Table of Contents

  1. The Florida Land Trust
  2. Martin County Case - when counties don't follow their own land use plan
  3. Case Studies in Transferable Development Rights
  4. Department of Environmental Protection Application Forms
  5. University of Florida Web Resources for Urban Planning
  6. Federal Conservation Programs
  7. Agricultural Lands Retention Study
  8. Restoring the Urban Forest
  9. The Tree Ordinance Pasco Should Have
  10. Managing Space to Manage Growth 

The Florida Land Trust

The Florida Land Trust

The Florida Land Trust is an amazing device which offers numerous benefits to property owners. The two reasons it is not used by every investor are that few know much about it and those who know about it do not know where to obtain trust services at a reasonable cost.

Trusts in general go back many hundreds of years and today they offer even more benefits than they did when they were invented. The Florida land trust is a statutory form of the "Illinois-type" land trust which has been used for over a hundred years.

The most important benefits of the land trust are privacy and avoidance of probate. With a land trust, no one needs to know what real estate you own either during your life nor at your death, and by avoiding probate you avoid thousands of dollars in attorney fees and months delay in distribution of your property to your heirs.

By using a land trust with Land Trust Service Corporation as trustee, there will be no public record of your ownership of the real estate in the trust. The public records will list the corporation as trustee, and the tax bill will be sent to the trustee (who will forward it to you for payment). The property will be managed by you or by your agent. Income tax returns will be filed by you in the same way they would for property in your own name.

Over twenty other benefits of using a land trust are listed in the book, Land Trusts in Florida, which you should read if you are planning to use a land trust. Some of the most popular benefits are, keeping the sales price secret, keeping liens and judgments off the property, avoiding a spouse's forced share, and avoiding litigation.

The beneficiary of your trust can be you individually, a corporation, a limited liability company, a partnership or any other legal entity. If you are the beneficiary individually, you can name any other person or entity to immediately become successor beneficiary upon your death. If your company is the beneficiary, you can name a successor in your company papers.

Besides a beneficiary, you can have a director. For example, you can set up a trust in which your children are the beneficiaries (paying the taxes on income) but you are the director. As director you would make all the decisions regarding the property. If you loan someone money you can have them put their property in a land trust and make you the director. Then you could control the property until you were paid in full.

 

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Martin County Case - when counties don't follow their own land use plan

IN THE DISTRICT COURT OF APPEAL OF THE STATE OF FLORIDA

FOURTH DISTRICT JULY TERM 2001

PINECREST LAKES, INC.; and

VILLAS AT PINECREST LAKES

LIMITED PARTNERSHIP,

Appellants,

v.

KAREN SHIDEL,

Appellee.

CASE NO. 4D99-2641

Opinion filed September 26, 2001

Appeal from the Circuit Court for the

Nineteenth Judicial Circuit, Martin County; Larry

Schack, Judge; L.T. Case No. 96-126 CA.

Jack J. Aiello and Ernest A. Cox, III, of

Gunster, Yoakley, Valdes-Fauli & Stewart, P.A.,

West Palm Beach, for appellants.

Richard Grosso, General Counsel, Environmental

& Land Use Law Center, Fort Lauderdale, for

appellee.

Stephen H. Grimes and Lawrence E. Sellers, Jr.

of Holland & Knight, LLP., Tallahassee, for Amici

Curiae, National Association of Home Builders,

Florida Home Builders Association, Florida

Association of Realtors, and Association of Florida

Community Developers, Inc.

Michael L. Rosen, Tallahassee, for Amicus

Curiae, Florida Legal Foundation, Inc.

Terrell K. Arline, Legal Director, Tallahassee,

Thomas G. Pelham, Kenneth J. Goldberg and

Douglas W. Ackerman, Tallahassee, for Amici

Curiae, The Florida Chapter of the American

Planning Association, and 1000 Friends of Florida,

Inc.

CORRECTED OPINION

FARMER, J.

The ultimate issue raised in this case is

unprecedented in Florida. The question is whether

a trial court has the authority to order the complete

demolition and removal of several multi-story

buildings because the buildings are inconsistent

with the County’s comprehensive land use plan.

We conclude that the court is so empowered and

affirm the decision under review.

Some twenty years ago, a developer1 purchased

a 500-acre parcel of land in Martin County and set

out to develop it in phases. Development there is

governed by the Martin County Comprehensive

Plan (the Comprehensive Plan).2 Phase One of

the property was designated under the

Comprehensive Plan as “Residential Estate,”

meaning single-family homes on individual lots

with a maximum density of 2 units per acre

(UPA). The Comprehensive Plan provides that

“[w]here single family structures comprise the

dominant structure type within these areas, new

development of undeveloped abutting lands shall

1Originally the developer was Pinecrest Lakes, Inc.,

the entity which planned and built Phases One through

Ten. In 1997, when we reversed the first appeal in this

case for a trial de novo, the corporation transferred title

to Phase Ten to a limited partnership known as The

Villas at Pinecrest Lakes. The trial court substituted the

limited partnership for the corporation as the developer.

Consequently, when we use the term “developer” in

this opinion, we refer either to the corporation or the

limited partnership or both as the context requires.

2See § 163.3167(2), Fla. Stat. (2000) (“Each local

government shall prepare a comprehensive plan of the

type and in the manner set out in this act or shall

prepare amendments to its existing comprehensive plan

to conform it to the requirements of this part in the

manner set out in this part.”).

(2)

be required to include compatible structure types

of land immediately adjacent to existing single

family development.” [e.s.]

Phases One through Nine were developed as

single-family homes on individual lots in very low

densities.

The subject of this litigation, Phase Ten, is a 21-

acre parcel between Phase One and Jensen

Beach Boulevard, a divided highway designated

both as “major” and “arterial.” Phase Ten was

designated by the Comprehensive Plan as

“Medium Density Residential” with a maximum of

8 UPA. The developer sought approval of three

different site plans before finally erecting the

buildings that are the subject of this litigation. In

1988, the developer first sought approval for an

initial scheme of 3-story apartment buildings with

a density of just under 8 UPA. Karen Shidel,

since 1986 an owner of a single-family residence

in the adjoining area of Phase One, along with

other residents, opposed the project proposed by

the developer. This initial site plan for Phase Ten

was approved by the County but never acted

upon.

Five years later the developer changed the

proposed scheme to single family residences, and

the County Commission approved a revised site

plan for 29 single-family homes with a density of

1.37 UPA. Two years after that, however, the

developer again changed its mind and returned to

its original concept of multi-family structures. This

time, the developer sought to develop 136 units in

two-story buildings, with a density of 6.5 UPA.

The County’s growth management staff

recommended that the County Commission

approve this second revised site plan for Phase

Ten. Following a hearing at which a number of

people objected to the proposal, including Shidel,

the County Commission approved the revision and

issued a Development Order3 for Phase Ten

permitting the construction of 19 two-story

buildings.

Claiming statutory authority, Shidel and another

Phase One homeowner, one Charles Brooks,

along with the Homeowners Associations for

Phases One through Nine, then filed a verified

complaint with the Martin County Commission

challenging the consistency of the Development

Order with the Comprehensive Plan, requesting

rescission of the Development Order.4 In

response to the verified complaint, after a hearing

the County Commission confirmed its previous

decision to issue the Development Order.

Shidel and Brooks then filed a civil action in the

Circuit Court against Martin County under the

same statutory authority.5 They alleged that the

3See § 163.3164(7) and (8), Fla. Stat. (2000)

(“‘Development permit’ includes any building permit,

zoning permit, subdivision approval, rezoning,

certification, special exception, variance, or any other

official action of local government having the effect of

permitting the development of land.… ‘Development

order’ means any order granting, denying, or granting

with conditions an application for a development

permit.”).

4See § 163.3215(4), Fla. Stat. (2000) (“As a condition

precedent to the institution of an action pursuant to

this section, the complaining party shall first file a

verified complaint with the local government whose

actions are complained of, setting forth the facts upon

which the complaint is based and the relief sought by

the complaining party. The verified complaint shall be

filed no later than 30 days after the alleged inconsistent

action has been taken. The local government receiving

the complaint shall respond within 30 days after receipt

of the complaint. Thereafter, the complaining party may

institute the action authorized in this section. However,

the action shall be instituted no later than 30 days after

the expiration of the 30-day period which the local

government has to take appropriate action.”).

5See § 163.3215(1), Fla. Stat. (1995) (“Any aggrieved

or adversely affected party may maintain an action for

injunctive or other relief against any local government

to prevent such local government from taking any

action on a development order…which materially alters

the use or density or intensity of use on a particular

piece of property that is not consistent with the

comprehensive plan adopted under this part.”).

(3)

Development Order was inconsistent with the

Comprehensive Plan. The developer intervened.

Shidel and Brooks argued that their statutory

challenge was a de novo proceeding in which the

court should decide in the first instance whether

the Development Order was consistent with the

Comprehensive Plan. Martin County and the

developer argued that the proceeding was in the

nature of appellate review in which the County’s

determination was entitled to deference and the

court should consider only whether there was

substantial competent evidence supporting the

Development Order. Basing its decision solely on

a review of the record created before the County

Commission, the trial court found that the

Development Order was consistent with the

Comprehensive Plan and entered final judgment in

favor of the developer.

At that point, the developer took stock of its

position. It had prevailed before the County

Commission and—at least initially—in the trial

court. Technically, however, its approval for the

project was not final. Developer considered

whether to proceed to construct the buildings or

instead await appellate review of the trial court’s

decision. Ultimately the developer decided to

commence construction, notwithstanding the

pendency of an appeal. Accordingly, it applied for

and received building permits for construction of

Buildings 8, 9, 10, 11 and 12, and started on each

of those buildings while the case was under

consideration in court.6 When construction was

just beginning, Shidel and Brooks sent written

notice to the developer of their intention, should

they prove successful in court, to seek demolition

and removal of any construction undertaken while

judicial consideration of the consistency issue was

pending.

Appellate review did not produce the outcome

for which the developer had hoped. In 1997 we

reversed the trial court’s decision that the

County’s consistency determination complied with

the Comprehensive Plan. Poulos v. Martin

County, 700 So. 2d 163 (Fla. 4th DCA 1997).

Specifically, we concluded that section 163.3215

required de novo consideration in the trial court on

the consistency issue. Our opinion explained:

“if section 163.3215 was intended to provide for

the circuit court to conduct an appellate review

by certiorari, then the statutory language

permitting the filing of the action up to 90 days

after the granting of the development order is in

conflict with the 30 day deadline outlined under

the Florida Rules of Appellate Procedure.”

700 So. 2d at 165. We further adopted an analysis

by Judge Wentworth as to the meaning of section

163.3215:

“the…language in the statute…provides only for

a suit or action clearly contemplating an

evidentiary hearing before the court to

determine the consistency issue on its merits in

the light of the proceedings below but not

confined to the matters of record in such

proceedings.”

700 So. 2d at 166 (quoting from Gregory v. City

of Alachua, 553 So. 2d 206, 211 (Fla. 1st DCA

1989) (Wentworth, J., dissenting)). We remanded

the case for a trial de novo and for any

appropriate relief.

On remand, the trial judge7 proceeded in two

s tages: the first stage involved a determination

whether the Development Order was consistent

with the Comprehensive Plan; and the second

stage, which became necessary, addressed the

remedy. While the case was pending on remand,

developer continued with construction. The

County conducted final inspections of Building 11

and 12, issuing certificates of occupancy (CO),

and residents moved into the buildings. At the end

of the consistency phase, the trial court entered a

partial judgment finding that the Development

6We express no view on the propriety of Martin

County issuing building permits while the case was

pending in court.

7The original judge assigned to the case was rotated

into another division, so the case was assigned to a

new judge.

(4)

Order was not consistent with the Comprehensive

Plan. The trial de novo then proceeded to the

remedy.

At the conclusion of the remedy phase, the trial

court entered a Final Judgment. The court found

that the Comprehensive Plan established a

hierarchy of land uses, paying deferenc e to lower

density residential uses and providing protection to

those areas. The “tiering policy” required that, for

structures immediately adjacent to each other, any

new structures to be added to the area must be

both comparable and compatible to those already

built and occupied.8 The court then found

significant differences between the northern tier of

Phase One and the adjacent southern tier of

Phase Ten. The structures in Phase One were

single level, single family residences, while the

structures in Phase Ten were two-story apartment

buildings with eight residential units. Therefore,

the court found, the 8-residential unit, two-story,

apartment buildings in Phase Ten were not

compatible or comparable types of dwelling units

with the single family, single level residences in

Phase One; nor were they of comparable density.

Consequently, the court determined, the

Development Order was inconsistent with the

Comprehensive Plan.

As regards the remedy, the Final Judgment

found no evidence indicating that either Brooks or

the Homeowners Association were damaged by

any diminution in value. The court found that the

Homeowners Association was not a person within

the meaning of section 163.3215(2) and therefore

had no standing to seek relief under section

163.3215. Accordingly, only plaintiff Shidel was

entitled to seek injunctive relief under section

163.3215.

In granting such relief, the court found that the

developer had acted in bad faith. Specifically, the

court found that the developer continued

construction during the pendency of the prior

appeal and continued to build and lease during the

trial—even after losing on the consistency issue.

The court found that the developer “acted at [its]

own peril in doing precisely what this lawsuit

sought to prevent and now [is] subject to the

power of the court to compel restoration of the

status prior to construction.” The relief awarded

was:

(1) the Court permanently enjoined Martin

County from taking any further action on the

subject Development Order for Phase Ten,

other than to rescind it;

(2) the Court permanently enjoined developer

and its successors in interest from any further

development of Phase Ten under the subject

Development Order; and

(3) the Court ordered developer to remove all

apartment buildings from Phase Ten either

through demolition or physic al relocation by a

date certain.

When the Final Judgment was entered, five of the

eight-unit buildings had been constructed in Phase

Ten (Buildings 8-12). Buildings 11 and 12 had

already received their CO’s, and fifteen of their

sixteen units were actually occupied. Building 10

was fully completed and was awaiting final

inspection as of the date the remedies stage of

trial began. Buildings 8 and 9 were 50% and 66%

completed, respectively, also as of that date.

Following the entry of Final Judgment, the

developer filed this timely appeal and moved for

a stay pending review.9 The trial court granted a

8“A project immediately adjacent to lands used or

designated for lower intensity use should be given

lesser density. (1) For that portion of said project

abutting the existing development or area of lesser

density, a density transition zone of comparable

density and compatible dwelling unit types shall be

established [e.s.] in the new project for a depth from the

shared property line that is equivalent to the depth of

the first tier of the adjoining development’s lower

density (i.e. the depth of the first block of single-family

lots).” Comprehensive Plan, § 4-5(A)(2)(b).

9Neither Charles Brooks nor Martin County has

appealed the final judgment, or filed a brief in this

appeal by Karen Shidel.

(5)

stay only as to the demolition order, allowing

lessees to continue in possession of those

apartments in Buildings 9-12 under actual lease

when the trial court entered final judgment, as well

as to those leases in Building 8 in existence as of

the date of filing of the notice of appeal. The

developer was prohibited, however, from entering

into any renewals of existing leases upon

expiration of the original term or any new leases

of any apartments. Upon review, we affirmed the

stay order. We now explain our decision on the

merits.

I. The Consistency Issue

Initially the developer argues that the trial court

erred in the consistency phase by failing to accord

any deference to the County Commission’s

interpretation of its own Comprehensive Plan

when the County approved the second revised site

plan and its multi-story, multi-family buildings.

Conceding that the proceedings are de novo and

that the Development Order is subject to “strict

scrutiny” under the Comprehensive Plan as to the

consistency issue, the developer nevertheless

argues that the courts must bow to the County’s

interpretation of its own Comprehensive Plan and

the application of its many elements to the site

plan. Developer argues that the statutes and

cases accord such deference to a local

government’s interpretation of its own

Comprehensive Plan and that it was reversible

error for the trial court in this case to fail to do so.

In partic ular, developer relies on Southwest

Ranches Homeowners Ass’n v. Broward

County, 502 So. 2d 931 (Fla. 4th DCA 1987), and

B.B. McCormick & Sons, Inc. v. City of

Jacksonville, 559 So. 2d 252 (Fla. 1st DCA

1990). According to developer, these cases

authorize the use of the highly deferential “fairly

debatable” standard of review—customary with

zoning decisions—to land use determinations such

as the issue of consistency in this case. We

disagree.

As we have already seen in this dispute, the

applicable statute provides that:

“[a]ny aggrieved or adversely affected party

may maintain an action for injunctive or other

relief against any local government to prevent

such local government from taking any action on

a development order…which materially alters

the use or density or intensity of use on a

particular piece of property that is not consistent

with the comprehensive plan….”

§ 163.3215(1), Fla. Stat. (2000). This statute

obviously creates an action for an injunction

against the enforcement of a development order,

rather than to carry out such an order. The

statute is aimed at development orders—which, by

their very nature, must have been approved by a

local government—so it is clear that the

Legislature did not mean that local governments or

developers would be the parties seeking injunctive

relief under this provision.

Moreover there is but one basis for issuing the

injunction: that the development order is not

consistent with the Comprehensive Plan to the

detriment of adjoining property owners. Hence

the issuance of an injunction under section

163.3215(1) necessarily requires the judge to

determine in the first instance whether a

development order is consistent with the

Comprehensive Plan. When a statute authorizes a

citizen to bring an action to enjoin official conduct

that is made improper by the statute, and that

same statute necessitates a determination by the

judge in the action as to whether the official’s

conduct was improper under the statute, as a

general matter the requirement for a determination

of the propriety of the official action should not be

understood as requiring the court to defer to the

official whose conduct is being judged. While the

Legislature could nevertheless possibly have some

reason to require some deference to the officials

whose conduct was thus put in issue, we would

certainly expect to see such a requirement of

deference spelled out in the statute with

unmistakable clarity. Here it is not a question of

any lack of clarity; the statute is utterly silent on

the notion of deference. It is thus apparent that

(6)

the structure and text of the statute do not

impliedly involve any deference to the decision of

the county officials. So we necessarily presume

none was intended.10

Section 163.3194 requires that all development

conform to the approved Comprehensive Plan, and

that development orders be consistent with that

Plan.11 The statute is framed as a rule, a

command to cities and counties that they must

comply with their own Comprehensive Plans after

they have been approved by the State. The

statute does not say that local governments shall

have some discretion as to whether a proposed

development should be consistent with the

Comprehensive Plan. Consistency with a

Comprehensive Plan is therefore not a

discretionary matter. When the Legislature wants

to give an agency discretion and then for the

courts to defer to such discretion, it knows how to

say that. Here it has not. We thus reject the

developer’s contention that the trial court erred in

failing to defer to the County’s interpretation of its

own comprehensive plan.

Before we proceed to assess the trial court’s

determination on the consistency issue, we pause

to consider the history of the land development

statutes. The State of Florida did not assert

meaningful formal control over the explosive and

unplanned development of land in this state until

the passage of the first growth management

statute, the Local Government Comprehensive

Planning Act of 1975. Chapter 75-257, Laws of

Fla. (the 1975 Act). The 1975 Act forced

counties and cities to adopt comprehensive plans,

but they were left to interpret such plans for

themselves, largely free from effective oversight

by the state. See, e.g., City of Jacksonville

Beach v. Grubbs, 461 So. 2d 160, 163 (Fla. 1st

DCA 1984) (determination of when to conform

more restrictive zoning ordinances with

Comprehensive Plan is legislative judgment to be

made by local governing body, subject only to

limited judicial review for patent arbitrariness).

The requirement of adopting a Comprehensive

Plan was, therefore, only a small step. Moreover

nothing in the legislation required local

governments to comply with their own

Comprehensive Plans or that all development be

consistent with the Plan.

By the early 1980’s it was widely recognized

10To illustrate the point, we draw an analogy. The

action by a county approving a development order

could fairly and logically be compared to the actions of

administrative agencies generally. Thus we might

contrast section 163.3215(1) with comparable provisions

of the Administrative Procedures Act. Section 120.68

generally grants parties in agency proceedings access

to a court after the agency has finally acted. Section

120.68(4), however, limits review to the record in

agency. There is no similar provision in section

163.3215. Moreover section 120.68(7) spells out in

precise detail exactly what the reviewing court can do.

Among its provisions is the following:

“The court shall remand a case to the agency for

further proceedings consistent with the court’s

decision or set aside agency action, as appropriate,

when it finds that … (b) The agency’s action

depends on any finding of fact that is not supported

by competent, substantial evidence in the record of

a hearing conducted pursuant to ss. 120.569 and

120.57; however, the court shall not substitute its

judgment for that of the agency as to the weight of

the evidence on any disputed finding of fact … (e)

the agency’s exercise of discretion was: 1. outside

the range of discretion delegated to the agency by

law; 2. inconsistent with agency rule; 3. inconsistent

with officially stated agency policy or a prior agency

practice, if deviation therefrom is not explained by the

agency; or 4. otherwise in violation of a

constitutional or statutory provision; but the court

shall not substitute its judgment for that of the

agency on an issue of discretion.” [e.s.]

§ 120.68(7), Fla. Stat. (2000). There is nothing even

remotely comparable in section 163.3215.

11See § 163.3194(1)(a), Fla. Stat. (2000) (“After a

comprehensive plan…has been adopted in conformity

with this act, all development undertaken by, and all

actions taken in regard to development orders by,

governmental agencies in regard to land covered by

such plan or element shall be consistent with such plan or element as adopted.”). [e.s.]

(7)

that the 1975 Act was proving ineffectual in

regulating Florida’s development. See Reid

Ewing, Florida’s Growth Management

Learning Curve, 19 VA. ENVTL. L. J. 375

(2000). The lack of state control over

interpretation of the Comprehensive Plan was

often cited as a serious deficiency. As one such

criticism described the situation:

“[f]rustration grew at the state level as well.

Lacking the actual power to approve or

disapprove local planning decisions, state and

regional planners could not effectively

coordinate and oversee local planning and

regulation. Local governments changed their

plans ‘willy-nilly virtually every time a city

council or county commission met...’ ”

John M. DeGrove, State and Regional Planning

and Regulatory Activity: The Florida

Experience and Lessons for Other

Jurisdictions, C390 ALI– ABA 397, 428 (1994).

For another thing, the 1975 Act was criticized

for failing to give affected property owners and

citizen groups standing to challenge the land

development decisions of local governments on the

grounds that they were inconsistent with the

Comprehensive Plan. The standing issue was

considered in Citizens Growth Management

Coalition of West Palm Beach Inc. v. City of

West Palm Beach, 450 So. 2d 204 (Fla. 1984)

(CGMC). CGMC involved a challenge by a

citizens group to a local decision to allow the

construction of a large scale residential and

commercial complex. The court began by

referring to Renard v. Dade County, 261 So.2d

832 (Fla. 1972), holding that standing to challenge

local development decisions was limited to the

highly deferential “fairly debatable” standard.

Affected property owners in the vicinity of new

development had no standing to seek enforcement

of local comprehensive plans unless they could

“prove special damages different in kind from that

suffered by the community as a whole.” 261 So.

2d at 834. The CGMC court determined that the

1975 Act did not change these rules on standing.

450 So. 2d at 208. The court reasoned that

because the 1975 Act “did not specifically address

the question” of standing, the statute was not

meant to alter the common law standing

requirements set forth in Renard. 450 So. 2d at

206-07.

Again, to return to the criticism, this limitation on

standing to enforce local planning laws resulted in:

“a failure to conform development decisions to

the plan based upon the fact that citizens lacked

standing to challenge development orders for

lack of consistency with the comprehensive

plan.”

James C. Nicholas & Ruth L. Steiner, Growth

Management and Smart Growth in Florida, 35

WAKE FOREST L. REV. 645, 657 (2000)(quoting

Daniel W. O'Connell, Growth Management in

Florida: Will State and Local Governments Get

Their Acts Together?, FLORIDA ENVTL &

URBAN ISSUES, 1-5 (June 1984)). If affected

property owners in the area of newly permitted

development could not challenge a project on the

grounds that it would be inconsistent with the

Comprehensive Plan, that eliminated the only real

check on local government compliance—a

challenge by those most directly affected by a

proposed development.

The growing pressure for a fundamental change

in the growth management law is reflected in the

following statement made just prior to the

Legislature’s adoption of the current law in 1985:

“In response to this lack of citizen standing, a

citizen initiative began last year and thousands of

signatures were collected around the state to

bring the standing issue to a referendum vote.

The petition specific ally calls for a referendum

on the issues of giving citizens a right in the state

constitution to environmental health and welfare

and providing them with legal standing to sue if

government at the local, regional, or state level

is not doing its job.

“That initiative fell just a few thousand

signatures short of the required number for

qualifying for a referendum in 1984. However,

(8)

the initiative is continuing, and I feel confident that

the issue will be brought to the voters of the state

in 1985 unless the legislature addresses the issue

more effectively than it did last year.”

Kathleen Shea Abrams, An Environmental Word,

1 J. LAND USE & ENVTL LAW 155, 159 (1985).

Clearly the pressure from a “civically militant

electorate” was growing, and the elected

representatives took notice of it. The result was

the Growth Management Act of 1985. Chap. 85-

55, Laws of Fla. This is essentially the statute we

have today, parts of which have been cited in

preceding paragraphs.12 Its most important

provision for our purposes was section 163.3215,

the provision used by Shidel to bring this action

into court.

In Southwest Ranches, we observed that

section 163.3215 had liberalized standing

requirements and demonstrated “a clear legislative

policy in favor of the enforcement of

comprehensive plans by persons adversely

affected by local action.” 502 So. 2d at 935. In

Parker v. Leon County, 627 So. 2d 476, 480 (Fla.

1993), the court held that “the legislature enacted

section 163.3215 to ensure the standing for any

person who ‘will suffer an adverse effect to an

interest protected ... by the ... comprehensive

plan.’ ” 627 So. 2d at 479. The Parker court

quoted with approval the above passage from

Southwest Ranches. 627 So. 2d at 479. See also

Putnam County Envt’l Council, Inc. v. Board of

County Comm’rs of Putnam County, 757 So. 2d

590, 593 (Fla. 5th DCA 2000) (“That standard

changed, however, with the 1985 adoption of

section 163.3215, which liberalized the standing

requirements and ‘demonstrat[ed] a clear

legislative policy in favor of the enforcement of

comprehensive plans by persons adversely

affected by local action.’”). Thus, the criticism

described above certainly was of great influence

in the 1985 Legislature’s formulation of the new

standing provision. Affected citizens have been

given a significantly enhanced standing to

challenge the consistency of development

decisions with the Comprehensive Plan.

The Growth Management Act of 1985 was

discussed in what is now recognized as the most

significant land use decision by the supreme court

in the past decade, namely Board of County

Commissioners of Brevard County v. Snyder,

627 So. 2d 469 (Fla. 1993). Snyder involved a

parcel then zoned only for single family homes and

a proposed development of 5-6 units. The

proposal also necessarily required a change of

zoning. After substantial opposition, and in spite of

a favorable staff recommendation, the County

voted to deny the request without giving any

reasons. Certiorari was denied in the circuit court,

one judge dissenting. The Fifth District held that

rezoning actions entailing the application of a

general rule or policy to specific individuals,

interests, or activities are quasi-judicial in nature

and should be subjected to a stricter standard of

judicial review. The court found that the proposed

site plan was consistent with the Comprehensive

Plan, that there was no evidence supporting the

denial of any necessary rezoning, and that the

denial of the request without giving any reasons

was arbitrary and unreasonable.

After granting review, the supreme court was

first concerned with the level of review given by

the courts to such proceedings. The county took

the position that it had been faced with primarily a

legislative judgment because the landowner sought

rezoning. As the court noted:

“Both federal and state courts adopted a highly

deferential standard of judicial review early in

the history of local zoning. In Village of Euclid

v. Ambler Realty Co., 272 U.S. 365 (1926), the

United States Supreme Court held that ‘[i]f the

validity of the legislative classification for zoning

purposes be fairly debatable, the legislative

judgment must be allowed to control.’ This

Court expressly adopted the fairly debatable

principle in City of Miami Beach v. Ocean &

Inland Co., 147 Fla. 480, 3 So.2d 364 (1941).”

12See supra notes 2, 3, 4 and 5 and accompanying

text.

(9)

[c.o.]

627 So. 2d at 472. The court went on to note,

however, that this tolerant form of judicial review

had not proved satisfactory:

“Inhibited only by the loose judicial scrutiny

afforded by the fairly debatable rule, local zoning

systems developed in a markedly inconsistent

manner. Many land use experts and

practitioners have been critical of the local

zoning system. Richard Babcock deplored the

effect of ‘neighborhoodism’ and rank political

influence on the local decision-making process.

Richard F. Babcock, The Zoning Game (1966).

Mandelker and Tarlock recently stated that

‘zoning dec isions are too often ad hoc, sloppy

and self-serving decisions with well-defined

adverse consequences without off-setting

benefits.’ Daniel R. Mandelker and A. Dan

Tarlock, Shifting the Presumption of

Constitutionality in Land-Use Law, 24 URB.

LAW. 1, 2 (1992).”

627 So. 2d at 472-73.

The court explained that in Florida the 1975 Act

“was substantially strengthened by the Growth

Management Act [of 1985].” 627 So. 2d at 473.

After analyzing various provisions of the Growth

Management Act of 1985, the court stated:

“We also agree with the court below that the

review is subject to strict scrutiny. In practical

effect, the review by strict scrutiny in zoning

cases appears to be the same as that given in

the review of other quasi-judicial decisions. See

Lee County v. Sunbelt Equities, II, Ltd.

Partnership, 619 So.2d 996 (Fla. 2d DCA1993)

(The term ‘strict scrutiny’ aris es from the

necessity of strict compliance with

comprehensive plan.). This term as used in the

review of land use decisions must be

distinguished from the type of strict scrutiny

review afforded in some constitutional cases.

Compare Snyder v. Board of County

Comm'rs, 595 So.2d 65, 75-76 (Fla. 5th

DCA1991) (land use), and Machado v.

Musgrove 519 So.2d 629, 632 (Fla. 3d

DCA1987), review denied, 529 So.2d 693

(Fla.1988), and review denied, 529 So.2d 694

(Fla.1988) (land use), with In re Estate of

Greenberg, 390 So.2d 40, 42-43 (Fla.1980)

(general discussion of strict scrutiny review in

context of fundamental rights), appeal

dismissed, 450 U.S. 961 (1981), Florida High

Sch. Activities Ass'n v. Thomas, 434 So.2d 306

(Fla.1983) (equal protection), and Department

of Revenue v. Magazine Publishers of

America, Inc., 604 So.2d 459 (Fla.1992) (First

Amendment).” [e.s.]

627 So. 2d at 475.

In the foregoing quotation the supreme court

drew a distinction between the use of strict

scrutiny in land use cases and its use in other

contexts. The court approved the analyses of the

Fifth District in Snyder and the Third District in

Machado v. Musgrove, 519 So. 2d 629, 632 (Fla.

3d DCA 1987), review denied, 529 So. 2d 693

(Fla.), review denied, 529 So. 2d 694 (Fla. 1988),

regarding land use decisions. These courts

explained that strict scrutiny of local government

development orders is necessary to insure that the

local governments comply with the duty imposed

by section 163.3194 to make decis ions consistent

with the Comprehensive Plan. In discussing the

difference between a developer aggrieved by a

land use decision of local government and an

affected property owner in the vicinity aggrieved

by a proposed new development, the Snyder court

emphasized that section 163.3215 “provides a

remedy for third parties to challenge the

consistency of development orders.” 627 So. 2d

at 475.

As one pair of writers put it, “Snyder changed

the rules of the game for local government land

use approvals.” John W. Howell & David J.

Russ, Planning vs. Zoning: Snyder Decision

Changes Rezoning Standards, FLA. B.J., May

1994, at 16. And another pair noted:

“The easygoing ‘fairly debatable’ test for sitespecific

rezonings was abandoned and the ‘strict

scrutiny’ standard was adopted for the review

of development orders under a county’s

(10)

comprehensive master plan.”

Lucia A. Dougherty & Elliot H. Scherker, Rights,

Remedies, and Ratiocination: Toward a

Cohesive Approach to Appellate Review of

Land Use Orders After Board of County

Commissioners v. Snyder, 24 STET. L. REV. 311,

312 (1995). In light of this history, deferential

review of the kind advocated by developer here is

no longer the rule after Snyder.

Under section 163.3215 citizen enforcement is

the primary tool for insuring consistency of

development decisions with the Comprehensive

Plan. Deference by the courts—especially of the

kind argued by the developer in this case—would

not only be inconsistent with the text and structure

of the statute, but it would ignore the very reasons

for adopting the legislation in the first place.

When an affected property owner in the area of a

newly allowed development brings a consistency

challenge to a development order, a cause of

action—as it were—for compliance with the

Comprehensive Plan is presented to the court, in

which the judge is required to pay deference only

to the facts in the case and the applicable law. In

light of the text of section 163.3215 and the

foregoing history, we reject the developer’s

contention that the trial court erred in failing to

defer to the County’s interpretation of its own

Comprehensive Plan.

Having thus decided that the trial court was

correct in failing to accord any particular

deference to the Martin County Commission in its

interpretation of the Comprehensive Plan, we now

proceed to consider the court’s determination on

the consistency issue. The trial court explained its

decision as follows:

“The primary claim by [plaintiffs] is that the

juxtaposition of multi-story, multi-family

apartments in Phase 10 directly next to the

single family homes in Phase 1 violates a

number of provisions in the Comprehensive

Plan. The provision of the Comprehensive Plan

that is central to their argument is section 4-

5(A)(2)(b), known as the ‘tiering policy.’ [see n.

6, above]

“The tiering policy was added to the

Comprehensive Plan … to address how

development would be added to existing singlefamily

residential communities. There was a

concern … over how existing single-family

homes were being impacted by new, adjacent

denser developments. …

“The tiering policy required…a transition zone

along the southern portion of Phase 10 equal to

‘the depth of the first block of single-family lots’

within the northern portion of Phase 1. The

section requires that development in the first tier

of Phase 10 be limited to construction ‘of

comparable density and compatible dwelling unit

types.’ The court finds that the appropriate

measure is 225 feet, using the shortest average

depth method of computation.

“No transition zone was established for Phase

10. The buildings along the first tier of Phase 10

are multi-family, multi-story, and have balconies.

The southern tier of Phase 10 has a density of

6.6 [UPA]. The overall density of Phase 10 is

6.5 [UPA]. There is no meaningful difference

in density across the entire western portion of

Phase 10. The northern tier of Phase 1, on the

other hand, is comprised entirely of single-family

homes on 0.75 acre to 1.2 acre lots, with a

density of 0.94 [UPA].13

“There was no first tier transition zone

established for Phase 10 as mandated by section

4-5(A)(2)(b). That section is not the only

provision of the Comprehensive Plan that

mandated compatible structures within the first

tier of Phase 10. Section 4-4(M)(1)(e)(2)

provided:

… Where single family structures comprise

the dominant structure type within [residential

estate densities (RE-0.5A)], new development

on undeveloped abutting lands shall be

13At this point in the Final Judgment, the court went

on to show in a comparative table that the change in

density between the two tiers represented a 560%

difference, the change in population a 492% difference,

and the number of units a 418% difference.

(11)

required to include compatible structure types of

lands immediately adjacent to existing family

development.

… Phase 1 is designated RE-0.5A

“It is impossible … to examine the photographs

of the homes in the northern tier of Phase 1, and

the apartment buildings in the southern tier of

Phase 10, and find that they are either

‘compatible dwelling unit types’ or ‘compatible

structure types.’ The only residential structure

that could be less compatible with the northern

tier of Phase 1, would be a multi-story

condominium building. There is no compatibility

between the structures in the southern tier of

Phase 10 and the northern tier of Phase 1.

Further, an examination of the density of

development in the two tiers at issue, precludes

this court from finding that they are in any way

comparable.

“[B]uffering does not grant relief to the

[developer] under section 4-4(I)(5). That

section deals with buffering between

‘incompatible land uses.’ The more specific

Tiering Policy mandates compatibility. More

importantly, even to the extent that the

Comprehensive Plan might, in some instances,

provide a builder with the ability to buffer

changes in density, intensity or uses, the

language of sections 4-4(M)(1)(e)(2) and 4-

5(A)(2)(b) simply do not permit the type of

development that is under construction in Phase

10.”

“Based on the foregoing, the Court finds that

the Development Order is inconsistent with the

Comprehensive Plan. It is not compatible with,

nor does it further the objective, policies, land

uses, densities and intensities in the

Comprehensive Plan. § 163.3194(3)(a).” [e.o.]

We have carefully reviewed the record of the

trial and the evidence presented. It is apparent

that there is substantial competent evidence to

support these findings. Developer argues that the

court erred in its interpretation of the “tiering

policy,” in deeming it a mandatory requirement

rather than a discretionary guide. We conclude

that the trial court’s construction is consistent with

the plain meaning of the text of the

Comprehensive Plan. See Comprehensive Plan,

§ 4-5(A)(2)(b) (“a density transition zone of

comparable density and compatible dwelling unit

types shall be established in the new project for a

depth from the shared property line that is

equivalent to the depth of the first tier of the

adjoining development’s lower density (i.e. the

depth of the first block of single-family lots).”).

Moreover, given the evidence as to Martin

County’s adoption of the tiering policy, the record

clearly supports the finding that the policy was

intended to be applied in all instances of projects

abutting single-family residential areas. We

therefore affirm the finding of inconsistency and

proceed to explain our decision on the remedy.

II. Remedy of Demolition

Developer challenges what it terms the

“enormity and extremity of the injunctive remedy

imposed by the trial court.” It argues that the trial

court’s order requiring the demolition of 5 multifamily

residential buildings is the most radical

remedy ever mandated by a Florida court because

of an inconsistency with a Comprehensive Plan.

Specifically, the contention is that the trial judge

failed to balance the equities between the parties

and thus ignored the evidence of a $3.3 million

dollar loss the developer will suffer from the

demolition of the buildings. The court failed to

consider alternative remedies in damages, it

argues, that would have adequately remedied any

harm resulting from the construction of structures

inconsistent with the Comprehensive Plan.

Developer maintains that the trial court

erroneously failed to give meaningful consideration

to the traditional elements for the imposition of

injunctive relief. It contends that the trial court

proceeded on an erroneous conclusion that where

an injunc tion is sought on the basis of a statutory

violation, no proof is required as to the traditional

(12)

elements for an injunction.

Traditionally, as the trial judge noted, it is true

that injunctions are usually denied where the party

seeking such relief fails to demonstrate a clear

legal right, a particular harm for which there is no

adequate remedy at law, and that considerations

of the public interest would support the injunction.

See, e.g., St Lucie County v. St. Lucie Village,

603 So. 2d 1289, 1292 (Fla. 4th DCA 1992).

These are, of course, the necessary ingredients for

equitable relief when we labor in the interplay of

common law and equity, where ordinary legal

remedies are unavailing.

Nonetheless, as between the State legislature

and the several counties, the Legislature is the

dominant creator of public duties and citizen

rights.14 Recognizing that the Legislature has the

sole power to create such public duties and citizen

rights, it logically follows that the Legislature is

necessarily endowed with the authority to spec ify

precisely what remedies shall be used by judges to

enforce a statutory duty—regardless of whether

in general usage such a remedy usually requires

additional factors before it is traditionally

employed.

When the Legislature creates a public duty and

a corresponding right in its citizens to enforce the

duty it has created, and provides explicitly that the

remedy of vindication shall be an injunction, the

Legislature has not thereby encroached on judicial

powers, as the courts held in Harvey v.

Wittenberg, 384 So. 2d 940 (Fla. 3rd DCA 1980),

and Times Publishing Co. v. Williams, 222 So. 2d

470 (Fla. 2d DCA 1969). The Times Publishing

court explained its theory of encroachment thus:

“Injunctive relief is an extraordinary remedy

which issues only when justice requires and

there is not adequate remedy at law, and when

there is a real and imminent danger of

irreparable injury. Statutory authority for such

writs, as in the act before us, are not

uncommon; but it must be remembered that

such writs are in the first instance judicial writs.

If such statutes purport to give the circuit courts

injunctive power they are ineffectual, since

those courts are otherwise vested with such

powers under the constitution, § 6(3) Art. V

Constitution of Florida; and if they purport to

dictate to such courts when, how or under what

conditions injunctions should issue they would

constitute an unlawful legislative infringement on

a judicial function.” [e.s.]

222 So. 2d at 476. Times Publishing and Harvey

both held that the Legislature is limited to

specifying certain harms as irreparable, but the

court alone has the discretion to determine

whether the injunction should otherwise issue. We

disagree with this analysis.

We think that is too wooden a construction of

legislative powers where a statute is concededly

valid. In our view when the Legislature provides

for an injunction in these circumstances, it has

deliberately made the new public duty and its

corresponding right of enforcement an integrated

statutory prescription. By specifying that the

public interest requires that a certain duty be

vindicated in the courts and not primarily within

other branches of government, the Legislature is

well within its powers. Surely the Legislature’s

primary role in defining public policy under the

constitution is broad enough to enable it to specify

a legal remedy in an enactment, regardless of

whether the traditional judicial restrictions on that

remedy in other, non-statutory contexts would limit

its usage. As the author of the primary duty, the

Legislature alone shapes the form of its

effectuating mechanism.

In section 163.3215, we think the Legislature

has constructed such a statute. The statute leads

off with a declaration that:

“Any aggrieved or adversely affec ted party

may maintain an action for injunctive or other

14See Art. VIII, § 1(f) and (g), Fla. Const. (whether

charter or non-charter government, Counties are

granted power to enact only ordinances that are “not

inconsistent with general law”).

(13)

relief against any local government to prevent

such local government from taking any action on

a development order, as defined in s. 163.3164,

which materially alters the use or density or

intensity of use on a particular piece of property

that is not consistent with the comprehensive plan

adopted under this part.”

From the plain and obvious meaning of this text

we discern only two elements to the granting of an

injunction against the enforcement of a

development order: (a) the party is affected or

aggrieved by (b) an approved project that is

inconsistent with the Comprehensive Plan. In

short, the existence of an affected neighbor is all

that is necessary for the issuance of an injunction

against a proposed land use that is inconsistent

with the Comprehensive Plan.

We note that the statute does not say that the

affected/aggrieved party bringing the action

“creates a presumption of irreparable injury” by

showing an inconsistency with the Plan. See, e.g.,

§ 542.335(1)(j), Fla. Stat. (2000) (“The violation of

an enforceable restrictive covenant creates a

presumption of irreparable injury to the person

seeking enforcement of a restrictive covenant.”).

When the Legislature wants to make a lesser

intrusion on traditional equitable jurisdiction, it

obviously knows how to do so. Here the statutory

text makes the injunction the first and preferred

remedy to alleviate the affects of in inconsistent

land use. Hence, we read the statute to make the

injunction the presumed remedy where the

conditions prescribed are shown.15

We disagree with the developer’s contention

that this statute was meant to create mere

discretion in the court to issue an injunction. If

injunctive relief is the specified, primary remedy to

correct a violation of a public duty and to vindicate

the right of a person affected by the violation of

that duty, it can properly be deemed a rule that the

Legislature has created, not a grant of discretion.

Here the Legislature has devised an entire

statutory scheme to insure that all counties have a

Comprehensive Plan for the development of land

within their respective jurisdictions. The scheme

creates mandatory duties to have a plan,

mandatory duties to have the plan approved by the

state, and once approved mandatory duties to limit

all developments so that they are consistent with

the plan’s requirements. At the end of all these

mandatory duties—all these shalls—comes a new

relaxation of the requirements on standing for

citizen suits to enforce comprehensive land use

15We reject developer’s argument that demolition is

improper simply because Shidel failed to seek a

temporary injunction against any construction while

the case proceeded in court on the consistency issue.

In the first place, when the action was filed the trial

court originally thought its role limited to a record

review of the proceedings before the Martin County

Commission and concluded that no error had been

shown. Having decided there was no error in the

limited review it thought applicable, the trial court was

hardly likely to grant a temporary injunction while the

case was on appeal.

Even more important, however, we find nothing in the

text of the relevant statutes making such a request for

a temporary injunction a precondition to effective final

relief after a trial de novo when the court finds that the

permitted use is inconsistent with the Comprehensive

Plan. We note from other statutes that when the

Legislature means to place restrictions on third party

challenges to agency decisions granting permits, it

says so in specific text. Compare § 403.412(2)(c), Fla.

Stat. (2000), with § 163.3215(4), Fla. Stat. (2000), as to

preconditions for suit; see also § 163.3215(6), Fla. Stat.

(2000) (“The signature of an attorney or party

constitutes a certificate that he or she has read the

pleading, motion, or other paper and that, to the best of

his or her knowledge, information, and belief formed

after reasonable inquiry, it is not interposed for any

improper purpose, such as to harass or to cause

unnecessary delay or for economic advantage,

competitive reasons or frivolous purposes or needless

increase in the cost of litigation. If a pleading, motion,

or other paper is signed in violation of these

requirements, the court, upon motion or its own

initiative, shall impose upon the person who signed it,

a represented party, or both, an appropriate sanction,

which may include an order to pay to the other party or

parties the amount of reasonable expenses incurred

because of the filing of the pleading, motion, or other

paper, including a reasonable attorney's fee.”).

(14)

plans and providing for the issuance of injunctions

when an inconsistency affects another land

owner. Judicial construction of that sole remedy

as discretionary strikes us as remarkably

inconsistent with not only the text of the statute

itself but also with the purpose of the entire

legislative scheme.

Developer lays great stress on the size of the

monetary loss that it claims it will suffer from

demolition, as opposed to the much smaller

diminution in value that the affected property

owner bringing this action may have suffered. It

contends that a $3.3 million loss far outweighs the

evidence of diminution in the value of Shidel’s

property, less than $26,000. Its primary contention

here is that the trial judge erred in failing to weigh

these equities in its favor and deny any remedy of

demolition. Instead, as developer sees it, the court

should have awarded money damages to eliminate

the objector’s diminution in value. Developer also

argued that instead of demolition it should be

allowed to build environmental barriers, green

areas of trees and shrubbery, between the

apartment buildings and the adjoining area of

single family homes.

Developer emphasizes that we deal here with an

expensive development: “a high quality, upscale

project;” “forty units of high-quality garden

apartments;” “five upscale multi-family dwellings,

housing 40 garden apartments, at a value of

approximately $3 million.” Developer concedes

that there is evidence showing that plaintiff

Shidel’s property is diminished by $26,000. It also

concedes that the total diminution for all the homes

bordering its project is just under $300,000.

Developer contends, however, that the real

countervailing harm to all these affected property

owners in the vicinity is not any diminution in the

value of their homes, but instead is merely

“knowing that there is an upscale apartment

building approximately a football field away,

partially visible through some trees behind the

house.”

Section 163.3215 says nothing about weighing

these specific equities before granting an

injunction. If the Legislature had intended that

injunctive enforcement of comprehensive plans in

the courts be limited to cases where such

imbalances of equities were not present, we

assume that it would have said so. As important,

such balancing if applied generally would lead to

substantial non-compliance with comprehensive

plans. We doubt that there will be many instances

where the cost of the newly allowed construction

will be less than any diminution resulting from an

inconsistency. Entire projects of the kind

permitted here will frequently far exceed the

monetary harms caused to individual neighbors

affected by the inconsistency. In other words, if

balancing the equities—that is, weighing the loss

suffered by the developer against the diminution in

value of the objecting party—were required

before demolition could be ordered, then

demolition will never be ordered.

Moreover it is an argument that would allow

those with financial resources to buy their way out

of compliance with comprehensive plans. In all

cases where the proposed use is for multiple acres

and multiple buildings, the expenditures will be

great. The greater will be its cost, and so will be

a resulting loss from an after-the-fact demolition

order. The more costly and elaborate the project,

the greater will be the “imbalance in the equities.”

The more a developer is able to gild an

inconsistency with nature’s ornaments—trees,

plants, flowers and their symbiotic fauna—the

more certain under this argument will be the result

that no court will enjoin an inconsistency and

require its removal if already built.

In this case the alleged inequity could have been

entirely avoided if developer had simply awaited

the exhaustion of all legal remedies before

undertaking construction. It is therefore difficult

to perceive from the record any great inequity in

requiring demolition. Shidel let the developer

know when it was just beginning construction of

the first building that she would seek demolition if

(15)

the court found the project inconsistent. When

developer decided to proceed with construction in

spite of the absence of a final decision as to the

merits of the challenge under section 163.3215, the

developer was quite able to foresee that it might

lose the action in court. It could not have had a

reasonable expectation that its right to build what

it had proposed was finally settled. It may have

thought the decision to build before the

consistency question was settled in court a

reasonable “business decision,” but that hardly

makes it inequitable to enforce the rule as written.

It also seems quite inappropriate, if balancing of

equities were truly required by this statute, to

focus on the relatively small financial impacts

suffered by those adjoining an inconsistent land

use. The real countervailing equity to any

monetary loss of the developer is in the flouting of

the legal requirements of the Comprehensive Plan.

Every citizen in the community is intangibly

harmed by a failure to comply with the

Comprehensive Plan, even those whose properties

may not have been directly diminished in value.

We claim to be a society of laws, not of

individual eccentricities in attempting to evade the

rule of law. A society of law must respect law,

not its evasion. If the rule of law requires land

uses to meet specific standards, then allowing

those who develop land to escape its requirements

by spending a project out of compliance would

make the standards of growth management of

little real consequence. It would allow developers

such as this one to build in defiance of the limits

and then escape compliance by making the cost of

correction too high. That would render section

163.3215 meaningless and ineffectual.

In this regard we are drawn to the views

expressed in Welton v. 40 Oak Street Building.

Corp., 70 F.2d 377 (7th Cir. 1934), a case of

strikingly analogous facts. There the developer

applied for a permit to erect a building, and

proceeded to build while its neighbor objected to

the edifice and sought to show that the building

plans did not comply with the zoning ordinances.

When the agency approved the building he sought

relief in the courts, finally being victorious in the

state supreme court. Ownership of the building

meanwhile passed to a federal receiver, and so the

objecting neighbor sought to enforce his remedy

by injunctive relief in the federal court. The trial

judge denied an injunction. On appeal the Court of

Appeals disagreed and ordered a mandatory

injunction to “rebuild” the edifice in compliance

with the zoning law, explaining:

“We have earnestly endeavored to place

ourselves in a position to fully appreciate

appellees’ argument to the effect that

enforcement of a right which arises out of an

effort to give light and air to metropolitan areas

is an equity that is outweighed by the dollars

advanced by builders of twenty story buildings in

defiance of zoning ordinances. We have also

endeavored to obtain appellees’ viewpoint when

they propose a money judgment to one who

suffers small financial loss as satisfaction for

violation of important ordinances enacted for the

benefit of the public. In the fight for better living

conditions in large cities, in the contest for more

light and air, more health and comfort, the scales

are not well balanced if dividends to the

individuals outweigh health and happiness to the

community. Financial relief to appellants is not

the only factor in weighing equities. There is

involved that immeasurable but nevertheless

vital element of respect for, and compliance

with, the health ordinance of the city. The

surest way to stop the erection of high buildings

in defiance of zoning ordinances is to remove all

possibility of gain to those who build illegally.

Prevention will never be accomplished by

compromise after the building is erected, or

through payment of a small money judgment to

some individual whose financial loss is an

inconsequential item.”

70 F.2d at 382-83. We agree with the Seventh

Circuit that respect for law, in this case the

Comprehensive Plan, trumps any “inequity” of

financial loss arising from demolition.

(16)

Our understanding of section 163.3215 is thus

different from equity’s traditional use of its

remedies. If, as we have shown, an injunction is

the statutory remedy to insure consistency of

development of property within the county, it does

not seem to us that the kind of balancing

advocated here would further that goal. In fact it

would very likely lead to even more inconsistent

development, particularly as to the kind of large

scale projec t involved here with multiple buildings

for multiple families. As we see it, the purpose of

this statute is precisely against this kind of

thinking. A clear rule is far more likely to erase

the kind of legal unpredictability lamented by

developer and amici.

The statute says that an affected or aggrieved

party may bring an action to enjoin an inconsistent

development allowed by the County under its

Comprehensive Plan. The statutory rule is that if

you build it, and in court it later proves

inconsistent, it will have to come down. The

court’s injunction enforces the statutory scheme

as written. The County has been ordered to

comply with its own Comprehensive Plan and

restrained from allowing inconsistent development;

and the developer has been found to have built an

inconsistent land use and has been ordered to

remove it. The rule of law has prevailed.

We therefore affirm the final judgment of the

trial court in all respects.

GUNTHER and GROSS, JJ., concur.

NOT FINAL UNTIL DISPOSITION OF ANY TIMELY

FILED MOTION FOR REHEARING.

 

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Case Studies in Transferable Development Rights

TDR Case Studies Updates

 

Beyond Takings and Givings contains case studies of 142 TDR programs in 134 communities around the nation. Since that book went to press in January 2003, TDR programs have been adopted, discovered or updated in the following communities. Rick Pruetz, who prepares these profiles, runs a consulting practice specializing in TDR workshops, studies and ordinances. Please contact him at arje@attglobal.net with corrections, updates or information on additional programs.

 

 

 


 

Bainbridge Island, Washington

Blacksburg, Virginia

Calvert County, Maryland

Chesterfield Township, Burlington County, New Jersey

Clallam County, Washington

La Quinta, California

Los Ranchos de Albuquerque, New Mexico

Lumberton Township, Burlington County, New Jersey

Montgomery County, Maryland

New Castle County, Delaware

Redmond, Washington

Scottsdale, Arizona

Summit County, Utah

Vancouver, British Columbia

 

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Department of Environmental Protection Application Forms

Approved Appraiser List Application
Appraisals and appraisal reviews conducted for the Board of Trustees state owned lands must be conducted by appraisers on the Division of State Lands Approved Appraiser List per FAC 18-1.007(2)(a).

Aquatic Plant Removal Permit Application  (pdf  35k, requires Acrobat Reader)

Florida Forever Application [doc]

Application for processing and collecting aquatic plants for Importation, Transportation, Non-Nursery Cultivation, Possession, and Collection (pdf 95k, requires Acrobat Reader)  Rules

Application for removing aquatic plants (pdf  35k, requires Acrobat Reader) Rules

DEP 63-030 (16) (doc) Application for Recordable Document for Lands Filled Prior to July 1, 1975 Pursuant to Chapter 253.12(9) & (10), Florida Statutes

Affidavit Example for Lands Filled Prior to July 1, 1975-"75 Certificate"

DEP 63-031 (16) (doc) Application for Disclaimers to Confirm Title of Formerly Sovereignty Lands Pursuant to Chapter 253.129, Florida Statutes

DEP 63-032 (16) (doc) Application for Quitclaim Deed to Clear Title of Formerly Sovereignty Lands Pursuant to Chapter 253.12(6), Florida Statutes

DEP 62-068 (16) (doc) Application to Purchase Lands Lost Due to Artificial Erosion or Artificial Erosion and Avulsion

DEP 62-069 (16) (doc) Application for Disclaimer for Lands Lost Due to Avulsion

Exchange of land title to which title is vested in the Board of Trustees of the Internal Improvement Trust Fund of the State of Florida

Mineral, Oil, or Gas Lease Application

Private Upland Easement Application

Private Upland Lease Application

Surplus Land Application

 

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University of Florida Web Resourses for Urban Planning


SMATHERS LIBRARIES
---Web Resources for Urban Planning
-
Introduction

This guide provides links to websites of high quality of likely interest to researchers in architecture.  Recommendations for additions or revisions to this guide are welcomed.  This guide is one of three which make up the Architecture Subject Guide.  The other guides deal with Reference Collection sources and Databases.-

 

 
Indices and Compilations Florida Sites Codes Directories
Association of Collegiate Schools of Planning
Sustainability Federal, State, Local Government Web Sites Planning Associations & Organizations Related Associations Environmental Organizations and Sites Planning Centers & Institutes

Planning Subject Guide | AFA Library | UF Libraries | UF



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Federal Conservation Programs

Release No. 0456.04

Julie Quick (202) 720-4632

Mary Cressel (202) 690-0547

VENEMAN ANNOUNCES RELEASE OF $1.6 BILLION FOR VOLUNTARY CONSERVATION PROGRAMS ON WORKING LANDS

 

WASHINGTON, Oct. 22, 2004—Agriculture Secretary Ann M. Veneman today announced the release of $1.6 billion in fiscal year 2005 funding for conservation programs on working lands, which, by knowing the initial mandatory program funding and technical assistance levels well before the next planting season begins, will help producers connect their business decisions to protecting water, air, soil and wildlife.

"This is one of the largest investments in conservation on private lands in our nation’s history," Veneman said. "In making the announcement today, we are responding to agricultural producers who want greater certainty and predictability in their decisions regarding environmental stewardship before planting season begins."

Veneman said that these program funds were being provided much earlier than in the past.

"Releasing the funds earlier in the year gives farmers and ranchers more time to make sound decisions regarding conservation practices," said Veneman. "This announcement will make conservations programs fully operational in every state and give producers the information they need to develop more effective conservation plans."

Veneman added that this effort is another example of the Bush Administration’s commitment to providing the tools and resources that will help agriculture producers remain the best stewards of the land. For example, on Earth Day 2004, President Bush highlighted the progress made by USDA in restoring America’s wetlands and announced an aggressive national goal to increase overall wetland acres and quality by restoring, improving and protecting at least 3 million wetland acres over the next five years. To help meet this goal, the President called on Congress to pass his FY 2005 Budget request, which includes $4.4 billion for conservation programs. By surpassing the decade-old "no-net-loss" policy, the President sent a message that we can continue the fight against soil erosion, improve the quality of our water and air and enhance wildlife habitat across America’s productive agricultural landscape.

In August, the President announced an expansion of the Conservation Reserve Program (CRP). As part of this announcement, the President unveiled CRP initiatives to create 250,000 acres of habitat for the northern bobwhite quail and to restore 250,000 acres of wetlands and playa lakes located outside the 100-year floodplain.

 

 

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In September, the President issued an Executive Order, Facilitation of Cooperative Conservation, which promotes cooperative conservation. The Executive Order emphasized appropriate local participation in Federal decision-making, in accordance with respective agency missions, policies and regulations. Cooperative conservation will enhance the enjoyment of natural resources through greater protection of the environment by involving collaborative activity among Federal, State, local and tribal governments, private for-profit and nonprofit institutions, other nongovernmental entities and individuals.

To help implement these initiatives, the Administration is announcing the initial conservation funding allocation today to allow USDA’s Natural Resources Conservation Service (NRCS) conservationists to work with farmers and ranchers nationwide to improve soil, water, air and at-risk habitat on privately-owned working lands in several programs.

Fiscal year 2005 allocations include $1.310 billion in financial assistance and $306 million for technical assistance for NRCS voluntary conservation programs and other activities. Veneman said that States will receive additional money after Congress makes discretionary funding decisions.

With financial and technical assistance from NRCS, farmers, ranchers and other landowners will continue to address resource concerns on agricultural working lands, promote environmental quality, address challenges in water quality and quantity, protect prime farmland and grazing lands and protect valuable wetlands ecosystems and wildlife habitat.

Key conservation programs and allocations include:

Environmental Quality Incentives Program (EQIP): $793,590,395. EQIP assists farmers and ranchers to improve soil, air and water quality and other related resources on private working lands.

Ground and Surface Water Conservation (GSWC): $62,874,481. GSWC assists farmers and ranchers to conserve our nation’s ground and surface water resources. The funding will result in improving agricultural water use efficiency and result in a net savings to ground and surface water reserves.

Klamath Basin: $9,734,200. These funds will help farmers and ranchers to enhance water quality, reduce water usage by increasing irrigation efficiencies, and improve habitat for affected fish and wildlife in the Klamath Basin.

Wetlands Reserve Program (WRP): $244,533,800. WRP is a voluntary program that helps landowners restore, enhance and protect wetlands through permanent easements, 30-year easements and restoration cost-share agreements. The program works to maximize wildlife habitat and wetland functions and values. 

 

 

-more-

 

 

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Farm and Ranchland Protection Program (FRPP): $66,574,678. FRPP is a voluntary program that provides matching funds to state and local governments and non-governmental organizations to purchase conservation easements on farm and ranch land. Since 1996, FRPP, in partnership with state and local governments and nongovernmental organizations, has protected over 440,000 acres.

Grassland Reserve Program (GRP): $40,832,400. GRP is a voluntary program designed to protect and restore grasslands, biodiversity, wildlife habitat and reduce soil erosion while sustaining viable working ranches. In 2005, GRP will utilize over $2 million to benefit the Greater Sage Grouse in key western states and protect precious Tall Grass habitat in Kansas.

Wildlife Habitat Incentives Program (WHIP): $21,935,051. WHIP offers technical and financial assistance through long-term agreements to create, restore and enhance wildlife habitat for upland wildlife, wetland wildlife, threatened, endangered or at-risk species and fisheries as well as other types of wildlife.

Agricultural Management Assistance (AMA): $12,997,456. AMA is available in 15 states where participation in the Federal Crop Insurance Program has been historically low: Connecticut, Delaware, Maine, Maryland, Massachusetts, Nevada, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Utah, Vermont, West Virginia and Wyoming. It helps farmers and ranchers voluntarily address natural resource concerns by incorporating conservation into farming operations while managing financial risk.

Conservation Reserve Program (CRP): $56,599,700 in technical assistance. CRP, administered by the Farm Service Agency, encourages farmers and ranchers to voluntarily establish conservation practices to protect environmentally sensitive land, provide food and habitat for wildlife and protect ground and surface water from runoff and sedimentation. Since the inception of CRP in 1986, this program has helped reduce soil erosion by more than 40 percent and restored 1.8 million acres of critical wetland acreage.

In addition, the allocation includes dollars for the Conservation Security Program (CSP). It includes $32,386,009 for active contracts and $162,024,991 for 2005 sign-up. State allocations for sign-up will be made at a later date. CSP recognizes those producers who are excellent stewards of the land and are willing to do even more by supporting ongoing conservation stewardship of agricultural working lands. In 2004, CSP was offered in 18 watersheds. In 2005 it is expected to be available in watersheds in all 50 states and a renewable energy component will be introduced that rewards farmers and ranchers for converting to renewable energy fuels such as soy bio-diesel and ethanol, for recycling 100 percent of on-farm lubricants, and for implementing energy production, including wind, solar, geothermal, and methane production.

A list of allocation totals by states is attached. Additional information on conservation programs is available at http://www.nrcs.usda.gov/programs. Landowners who want specific information regarding program participation should contact their local USDA Service Center or NRCS office, locate at http://offices.usda.gov or in the telephone book under Federal Government, U.S. Department of Agriculture.

#

FY 2005 Conservation Funding Allocation Totals by State:

 

FLORIDA

$39,180,466

* State allocations for CSP sign-up will be made at a later date.

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AGRICULTURE AND RURAL AREA

STUDY

ANALYSIS OF AGRICULTURAL LAND

RETENTION STRATEGIES

TASK 2.B.

SUBMITTED BY:

ROBERT H. FREILICH, AICP, LL.M., J.D.

TYSON SMITH, AICP, J.D.

ELISA PASTER, M. SC.

FREILICH, LEITNER & CARLISLE

WITH SUPPORT FROM

TISCHLER & ASSOCIATES

AND

UNIVERSITY OF FLORIDA

Miami-Dade County Agriculture and Rural Area Study

Task 2(b)

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TABLE OF CONTENTS

I. Introduction..................................................................................................................2

A. Task 2: Agricultural and Rural Area Retention and Promotion Strategies .............2

B. Task 2(b): Analysis of Agricultural Land Retention Strategies ..............................2

C. The Goal: Protection of Agricultural Land Values and the Essential Character of

the Study Area .................................................................................................................3

II. Overview......................................................................................................................4

A. Land Use Growth Patterns .......................................................................................4

B. Agricultural Land .....................................................................................................6

C. Economic Impact of Agricultural Land ...................................................................7

D. Growth Management Challenges ............................................................................7

III. Agricultural and Rural Land Policies and Implementation Techniques..................8

A. Agricultural Zoning .................................................................................................8

1. Area Based Zoning ..............................................................................................9

2. Large Lot Zoning .................................................................................................9

3. Cluster Zoning ...................................................................................................10

4. Buffering............................................................................................................12

5. Overall Benefits and Drawbacks of Agricultural Zoning..................................14

B. Non-Zoning Techniques ........................................................................................15

1. Right-to-farm Laws ...........................................................................................15

2. Agricultural Districting......................................................................................17

3. Land Evaluation Systems ..................................................................................18

C. Land Acquisition Programs ...................................................................................20

1. Conservation Easements ....................................................................................20

2. Purchase of Development Rights.......................................................................20

3. Land Banking.....................................................................................................22

4. Transfer of Development Rights .......................................................................23

5. Florida Rural and Family Lands Protection Act ................................................26

D. Taxation Programs .................................................................................................27

1. Differential Assessment .....................................................................................27

2. Circuit Breaker Tax Relief Credits ....................................................................28

3. Real Estate Transfer Taxes ................................................................................29

E. Funding Programs..................................................................................................30

1. Impact Fees ........................................................................................................30

2. Environmental Mitigation Fees .........................................................................31

3. Federal Programs ...............................................................................................31

F. Regulatory Techniques ..........................................................................................32

1. Growth Tiers ......................................................................................................32

2. Concurrency Programs ......................................................................................33

3. Urban Service Boundaries .................................................................................34

IV. Economics and the Law.........................................................................................35

A. Economic Value of Land .......................................................................................35

B. Legal Framework ...................................................................................................35

1. Takings ..............................................................................................................36

2. Impact Fees/ Mitigation Fees.............................................................................37

3. Due Process .......................................................................................................38

V. Miami-Dade County – Value Preservation Principle ................................................38

VI. Conclusion.............................................................................................................39

Miami-Dade County Agriculture and Rural Area Study

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The authors have prepared this analysis in completion of Task 2(b)

of the Scope of Services, “Agricultural and Rural Area Retention and

Promotion Strategies.” It is not the goal of this analysis to propose one

solution or another as appropriate to the Study Area, or to suggest one

policy approach over any other. Rather, this analysis is intended to set

forth alternative techniques that the CAC may recommend and the County

may adopt in pursuit of its overarching land use objectives in the Study

Area.

Tyson Smith, of the law firm, Freilich, Leitner & Carlisle, and coauthor

of this analysis, attended the August 21, 2002 meeting of the CAC,

presented the findings made herein, and received the initial input of the

Committee. This Report reflects the comments received at that meeting,

as well as additional comments received from other members of the

Consultant Team, staff, and the TAC.

The Task 2(c) report, “Analysis of Rural Land Uses,” presents a

case analysis of five different communities around the country that have

incorporated a number of the preservation techniques discussed in this

report. In Task 2(c) we focused on the “value preservation” mechanisms –

e.g., purchase or transfer of development rights – applied by the

communities to achieve successful agriculture and rural area programs.

Value preservation mechanisms make most programs successful, due

mainly to the fact that they protect both the agricultural and the

preservation interests of the community. This Report provides an

overview of zoning and incentive driven programs that may, in the final

analysis, constitute the ultimate recommendation of the Consultant Team.

I. INTRODUCTION

A. Task 2: Agricultural and Rural Area Retention and Promotion Strategies

Task 2 of the Scope of Services focuses on a range of agriculture and rural area

retention, promotion, and economic development strategies. Task 2(a) presents and

analyzes information on various economic development issues; Task 2(c) introduces

related programs used in similarly situated rural areas of the country; and, finally, Task

2(d) will include a recommended approach for addressing the specific needs of Miami-

Dade County.

B. Task 2(b): Analysis of Agricultural Land Retention Strategies

Objective: Collect, analyze and present information regarding

agricultural land retention strategies and implementing programs used in

areas facing similar urbanization pressures, as well as development rights

programs, land swaps, or any other means to ensure that landowner

equity is maintained, with emphasis on the success of such programs, their

ability to solve shortcomings and their applicability to Miami-Dade

County without negative effects on agricultural competitiveness.

Miami-Dade County Agriculture and Rural Area Study

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The goal of Task 2(b) is to present and analyze information regarding agricultural

and rural land use strategies and programs used in areas facing development pressures

similar to those in existence or anticipated in the Study Area. Section II of this Report

provides a general overview of the range of issues that underlie the overall analysis being

undertaken by the Consultant Team (the “Team”). Section III sets out numerous

agriculture and rural land use techniques that are available to the County in pursuit of its

overall rural policies. Section IV assesses the applicability and legality of various land

use policies and preservation techniques within the Study Area. And, finally, Section V

sets forth the proposed framework for analyzing or determining a policy approach that

will achieve the dual goal of this analysis: the protection of land values and the

preservation of agriculture and rural open space within the Study Area.

C. The Goal: Protection of Agricultural Land Values and the Essential

Character of the Study Area

Preserving the value of agricultural land is imperative to ensuring long term

preservation of farming, open space, and managed growth. Farmers, growers, and

ranchers own 80 percent of the private land in Florida; land that provides wide-open

views of forestlands, green groves, and pastureland.1 However, many of these large-scale

property owners are selling their land because encroaching urban uses have deemed

agricultural uses economically non-viable. When land value is diminished, future

economic development is limited. During times of economic hardship, the agricultural

landowner may have to rely on the underlying value of his or her land to make financing

arrangements to cover the cost of operations. If land values are significantly reduced, so

are refinancing opportunities, leaving the farmer in difficult financial straits. Preserving

land values is beneficial not only for the land owner, but also for the entire community;

while the farmer continues to farm, the community benefits from open space and

managed growth.

This paper concludes with a proposal for analyzing and developing a “preferred

development scenario” for achieving the long-term land use goals for the Study Area.

The authors propose that this analysis – this weighing of alternative techniques and

approaches – be conducted in light of the actual economic reality that landowners in the

Study Area will face over a twenty-year period. Simply put, that decision will be

whether to retain existing holdings in their current use, or a significant portion thereof; or

to develop those holdings at some undetermined urban or suburban density.

The framework of this analysis presumes, first, that a combination of

agriculture/rural open space preservation and reasonable development will characterize

the Study Area over the next twenty years. Second, it further presumes that this

combination of land use intensities will be defined by adopted County policies, which in

turn, may be based significantly on the recommendations of the Team and the Citizens’

Advisory Committee (the “CAC”). Third, this analysis contemplates an ultimate

“preferred development scenario” – to be determined and articulated under Task 2(d) –

that preserves both property rights and rural character, but neither at the expense of the

1 Florida Farm Bureau, Growth Management, available at

http://www.fb.com/flfb/issues/2001/Growmgt.htm (August 2, 2002).

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other. The authors believe that reasonable policies can be drafted and implemented,

which will advance both property rights and the rural policies of the County, while

protecting land values throughout the Study Area. The Alternatives Analysis set forth at

Section V proposes a framework for arriving at that ultimate recommendation.

II. OVERVIEW

A. Land Use Growth Patterns

Florida is one of the fastest growing states in the nation, and rural lands still

constitute a majority of land within the state.2 While rural populations accounted for only

7 percent of the state’s population in 1997, the growth rate of rural Florida has been

outpacing the national average.3 From 1990 to 2000, the population of Miami-Dade

County grew 12.3 percent.4

Historically, Miami-Dade County’s land use patterns have reflected patterns

across America: loss of agricultural land to urban development; rising land prices on the

urban fringe; and urban sprawl. Since World War II the greatest proportion of growth

has taken place in the urban-rural fringes of major metropolitan centers. This type of

growth has led to the depletion and deprivation of important environmental resources,

including the loss of unique agricultural lands.5 As urban growth spreads into the rural

and semi-rural areas of Miami- Dade County, the character unique to the rural community

is threatened.6

In 1985, the Florida Legislature passed into law the Local Government

Comprehensive Planning and Land Development Regulations Act (the “Growth

Management Act”). The Growth Management Act set up a public hearing and permitting

process for regional planned growth that protects important public natural resources

including rivers, lakes, springs, state parks, and rare wildlife species. The Growth

Management Act mandates comprehensive planning for local governments and vested the

Florida Department of Community Affairs (DCA) with an oversight role. From local to

regional to statewide comprehensive plans, DCA provides checks and balances to growth

and development, ensuring that developers and existing taxpayers alike foot some of the

costs associated with growth such as new schools, roads, new utilities (drinking water,

sewage treatment, electric, telephone), municipal services (fire, police, ambulance), and

additional parks and recreation areas. 7

The County’s Comprehensive Development Master Plan and its accompanying

Land Use Planning (LUP) map guide land use patterns in Miami-Dade County. The

Urban Development Boundary (UDB) is one of the major components of the land use

strategy in Miami-Dade County as it demarcates where urban development ends and rural

2 Florida Chapter of the American Planning Association & 1000 Friends of Florida, Rural Florida:

Opportunities for the Future, 3 (February 2002).

3 Id.

4 South Florida Regional Planning Council, Table: Southeast Florida Components Of Population Change

available at http://www.sfrpc.com/region/sfcmigc1.htm (August 1, 2002).

5 Robert H. Freilich & Linda Kirts Davis, Saving the Land: The Utilization of Modern Techniques of

Growth Management to Preserve Rural and Agricultural America, 13 URB. LAW. 27, 29 (1981).

6 See Fred Heyer, Perserving Rural Character, APA Planning Advisory Service Report no. 429, 1 (1990).

7 See generally Fla. Stat. §163 (2002).

Miami-Dade County Agriculture and Rural Area Study

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development begins.8 The purpose of the UDB is to ensure that development only occurs

in areas where infrastructure is available and to ensure vital natural resources are

protected outside the boundary. Development within the UDB will be approved through

the year 2005 provided that adequate services and public facilities are available.9 The

LUP also has a year 2015 Urban Expansion Area (UEA) boundary. The UEA is

comprised of that area located between the 2005 UDB and the 2015 UEA boundary. It is

the area where current projections indicate that further urban development beyond the

2005 UDB boundary is likely to occur between 2005 and 2015. Until this area is brought

into the UDB area through plan and review amendment processes, parcels are allowed to

be used for agricultural and open space use.10

Any person or organization, including the federal government, the State of

Florida, Miami-Dade County, any municipality in Miami-Dade County and any of their

agencies, authorities and departments may request amendment of the UDB and UEA.

The County Commission must review the Comprehensive Development Master Plan

every two years and any proposed amendment to the UDB may only be submitted in odd

years during a certain period in April.11 In considering amendments to the UDB the

Commission must meet all the requirements of the Growth Management Act and will

consider issues such as population trends, demand on urban services, levels of service

available, development right demand, infill potential, environmental and agricultural

resources, and above all concurrency, which demands that local government phase

development so it occurs only after urban facilities or infrastructure have been provided.

In December of 1996, the Miami-Dade County Board of County Commissioners

passed Resolution No. 1477-96 establishing an Infill Strategy Task Force to study

opportunities and strategies to promote infill within the UDB. The Task Force’s 1997

final report recommended, among other things, that the UDB not be expanded for at least

ten years and that the policy of discouraging infrastructure investment outside the UDB

be continued.12

Comprehensive Development Master Plan policies reflect the need to discourage

sprawl development outside the UDB in order to preserve agriculture. Policy 8G states

that the UDB should contain developable land having capacity to sustain projected

countywide residential demand for a total period of 15 years after adoption of the most

recent Evaluation and Appraisal Report.13 Policy 8H further indicates that when

considering land areas to be added to the UDB, the Redland area (a prime agricultural

location) shall not be cons idered, and land designated for agricultural land uses on the

LUP shall be avoided.14 The Comprehensive Development Master Plan also indicates

that the principal uses in the “Agriculture” district should be agriculture and uses

ancillary to and directly supportive of agricultural. While uses ancillary and necessary to

agriculture may be permitted, the County should consider whether future schools should

8 MIAMI-DADE COUNTY, COMPREHENSIVE DEVELOPMENT MASTER PLAN at I-45 (2001).

9 Id.

10 Id. at I-46.

11 MIAMI-DADE COUNTY ZONING CODE, Sec. 2-116.1. (2002).

12 MIAMI-DADE COUNTY, supra note 8, at I-45.

13 Id. at I-16.

14Id at I-17.

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be located outside the agricultural area within the urban development areas of the

County.15

Though some agriculturally zoned land exists within the UDB, no new

commercial agricultural use of property may be established within the boundary (though

limited exceptions exist).16 This is consistent with a countywide strategy to maximize

densities and urban uses within the UDB and to maximize preservation of land values

within the community. Conversely, there are lands that are zoned agricultural within the

UDB but are re-designated for urban development pursuant to amendments to the

Comprehensive Development Master Plan in 1995. These lands shall be converted only

pursuant to policies within the Comprehensive Development Master Plan and contingent

on a Farmland Conservation Study. 17

Residential development is only permitted at a density of one unit per five acres

(1:5). Smaller residential parcels may be created only if the immediate area surrounding

the subject parcel on three sides is predominately parceled in a similar manner and if

division of the subject parcel would not encourage further land division in the area.18 No

business or industry (with the exception of packing houses) is allowed in the Agriculture

district unless it is directly related to agricultural uses, is located on an existing arterial

roadway, and a adequate water supply and sewage disposal exists in accordance with

County law. Other uses compatible with agriculture and rural residential character may

be approved based on a determination of public necessity or public interest; or if the

applicant can prove no other suitable site exists outside the Agriculture district.19

B. Agricultural Land

There are approximately 1.55 million acres in Miami-Dade County, ¾ of which

are under water, in water conservation areas or considered submarginal for urban or

agricultural uses.20 Agricultural uses in Miami-Dade County are located in the south

central portion of the County, also known as the Redland. There are considerable urban

land uses scattered throughout this agricultural area.

According to the Census of Agriculture, land devoted to agriculture has remained

fairly stable since the 1980s, ranging from 83 to 87 thousand acres, or approximately 7

percent of total county acreage.21 While the number of farms declined by 17 percent to

1,576 since 1992, the acreage of land devoted to agriculture actually increased 1.7

15Id. at I-47.

16 Id at I-45.

17 Id at I-46.

18 Id.

19 Id.

20 ROBERT DEGNER, TOM STEVENS, DAVID MULKEY, & ALAN HODGES, FLORIDA AGRICULTURAL

MARKETING RESEARCH CENTER, ECONOMIC IMPACT OF AGRICULTURE AND AGRIBUSINESS IN MIAMI-DADE

COUNTY, FLORIDA p. x (2000).

21 Id.

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percent in the same period to 85,093 acres.22 Agricultural land in Miami-Dade County is

considered to be among the most threatened in the nation. 23

Government agencies have played a significant role in the purchase of agricultural

land for conservation purposes. Between 1975 and 1998 over 10,300 acres of farmland

were purchased by governmental agencies, in particular by the South Florida Water

Management District (SFWMD). In 2000 it is estimated that the SFWMD leased

approximately 5,000 acres to private individuals.24

C. Economic Impact of Agricultural Land

Florida ranks in the top 10 states in total market agricultural value and its market

value per acre of farmland is also among one of the top ten producing states.25 The total

economic impact from all agricultural sales originating in Miami-Dade County exceeded

$1.07 billion for the 1997-98 crop year. Fresh vegetable production was the largest

contributor to this total with nearly $491 million, or 45.6 percent of the total. The

greenhouse/nursery industry was responsible for nearly 41 percent or $439.8 million of

the total economic impact. Although sales revenues generated by nurseries and

greenhouses exceeded revenues for vegetables by over $7 million during this period, a

greater proportion of vegetables are shipped outside the County, thereby generating more

"new" dollars and a greater economic impact. Sales of tropical fruits produced in the

County created an economic impact of $137 million, representing about 12.7 percent of

agriculture’s value. Miscellaneous livestock sales, including aquaculture, generated an

economic impact of about $8.2 million, representing less than one percent (1%) of

agriculture's total economic impact.

Agriculture created an estimated 14,795 jobs in Miami-Dade County for 1997/98.

Agriculture's impact on earnings in Miami-Dade County totaled over $362 million for

1997-98. Approximately 46.5 percent, or $168 million, of this earnings impact was

generated by the vegetable industry. More than 42 percent, or approximately $153

million, was contributed by the greenhouse and nursery subsector. The tropical fruit

subsector generated nearly $41 million (11.2 percent) and miscellaneous livestock was

responsible for $450 thousand (0.12 percent) of agricultural earnings impact for Miami-

Dade County in 1997.26

D. Growth Management Challenges

Miami- Dade County must establish alternative development patterns to encourage

managed growth and preserve values of agricultural land. Growth management

techniques must preserve the value of agricultural land, the environment, and

development rights while protecting urban viability and stability.

22 Id.

23 American Farmland Trust, Farming on the Edge (1997) available at

http://www.farmlandinfo.org/cae/foe2/ (July 31, 2002).

24 DEGNER, supra note 20, at x.

25 American Farmland Trust, supra note 23.

26 DEGNER, supra note 20, at x-xi.

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Implementation of a program must be legally defensible. Statutorily, local

government is required to protect and preserve land and to mitigate impacts on

environmental lands.27 However, in fulfillment of state mandate, private property rights

advocates may view any scheme that reduces land values as a taking under the Fifth

Amendment of the U.S. Constitution, the Florida Constitution, or the Bert J. Harris Act.28

Governments must balance the need to protect health, welfare and safety with the

guarantee for compensation for land that is taken for public purposes. The land use

program for Miami-Dade County must strive to strike equilibrium between these

competing interests.

Agricultural preservation must be part of a wider comprehensive planning

program. Community input is vital to enhance the quality of planning. Agricultural

landowners bring specific information about their needs to the table. In the long run, a

plan that combines planning and agricultural knowledge will enhance the quality of the

plan. An extensive public input process will also help to avoid unnecessary contention

between self-interested parties, including urban and agricultural dwellers and the

government. An effective public input process allows interests to resolve their

differences prior to adoption of any plan, and to ensure that the plan addresses the needs

of different groups.

III. AGRICULTURAL AND RURAL LAND POLICIES AND IMPLEMENTATION TECHNIQUES

This section focuses on techniques for agriculture and rural land retention. The

underlying goal is to: (1) achieve preservation of the lands most suitable for future

agricultural use; (2) achieve preservation of agricultural land values; and (3) preserve the

rural character of the area.

A. Agricultural Zoning

Zoning is the most utilized technique for preserving agriculture and rural lands.

Zoning land exclusively for agricultural uses prevents residential subdivisions while

simultaneously creating a holding zone to restrict urban expansion. 29

Miami- Dade County has a specific zone, an AU zone, that allows agricultural and

related uses including packing facilities, outdoor storage of farming equipment, farming,

cattle grazing, hog and dairy farms (but only after approval at a public hearing),

nurseries, greenhouses, groves, truck gardens, single-family homes, schools, day cares,

and group homes. Minimum lot size for a residential lot is five acres.

27 Julian Conrad Juergensmeyer, James C. Nichols, & Brian D. Leebrick, Transferable Development Rights

and Alternatives After Suitum, 30 URB. LAW. 441, 443 (1998).

28 Id.

29 ROBERT H. FREILICH, FROM SPRAWL TO SMART GROWTH: SUCCESSFUL LEGAL, PLANNING, AND

ENVIRONMENTAL SYSTEMS 284 (American Bar Association 1999).

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1. Area Based Zoning

Fixed area based zoning allows for one dwelling unit for a specified number of

acres. For example, the zoning ordinance in Lancaster County, Pennsylvania (See Task

2(c) Report) allows for one non-farm lot for every 50 acres. A non- farm lot subdivided

from its parent tract must be at least one acre, but not more than two.30 Similarly, the

quarter-quarter approach operates by splitting off land from the parent parcel, and

establishing a maximum or minimum parcel size for building lots. 31

Sliding scale zoning is another agricultural protection technique in which the

number of dwelling units permitted varies with the size of the tract. Owners of smaller

parcels may divide their land into more lots on a per-acre basis than owners of larger

parcels.32 Sliding scale zoning may also be used by qualitatively assessing land. For

example, Clinton County, Indiana allows denser development on lands with poor soil

quality and prohibits development on lands with high soil quality. 33

The rationale behind sliding scale zoning is to promote development on smaller

tracts that are on less valuable soil while prohibiting development on fertile, soil rich

lands.34 High-density development also satisfies the legal requirement that municipalities

permit some economically viable use of land when farming is not profitable.35

Critics of area based zoning suggest that a successful program must require that

properties be restricted with conservation easements to prevent further development after

the maximum density is reached.36 Communities that do not require conservation

easements or some other type of deed restriction will be in danger of losing the land to

non-agricultural uses in the future. The other potential problem with area based zoning is

that, like any zoning ordinance, it only exists as long as the political will to maintain and

enforce it exists. Communities must be willing to commit to this type of zoning over an

extended period of time for it to be successful.

On the other hand, this type of zoning is a very inexpensive way to protect land

because little public expenditure is necessary. Compared to other programs such as

TDRs or PDRs (discussed below), zoning can be implemented very quickly, and,

furthermore, the public is accustomed to these traditional zoning techniques.

2. Large Lot Zoning

Some communities have tried to slow rapid growth patterns by requiring rural

land to be subdivided into lots no smaller than five or more acres, with the intention that

30 AMERICAN FARMLAND TRUST , SAVING AMERICAN FARMLAND: WHAT WORKS 59 (1997).

31 METROPOLITAN MIAMI-DADE COUNTY PLANNING DEPARTMENT & METROPOLITAN MIAMI-DADE

COUNTY COOPERATIVE EXTENSION DEPARTMENT, MANAGEMENT OPTIONS EVALUATED FOR THE

RETENTION OF LAND FOR AGRICULTURE IN DADE COUNTY, FLORIDA 76 (1981).

32 AMERICAN FARMLAND TRUST , supra note 30, at 317

33 Id.

34 Id. at 60.

35 Id. at 60.

36 Id. at 59.

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larger parcels will maintain lower density and rural character. The intent also is to

protect water quality and environmental resources. As a rule of thumb, the minimum lot

size created is the amount of land necessary to carry on a successful farming operation,

thus, lot sizes reflect the economic reality of agriculture.37

Though large lot zoning was a traditional strategy to protect farmland in the 1970s

and 80s, the resulting development of subdivisions has suggested that it may not be the

most effective strategy. The main problem is that the lot size is not large enough to

discourage development, yet is too small for effective agriculture.38

Large lot zoning, therefore, is widely criticized for promoting sprawl and the

degradation of farmland. Large-lot zoning essentially converts farms and valued open

space into private property and large lawns, where little community open space is

preserved, and neighbors are isolated from each other by their islands of unproductive

private land. The resulting pattern becomes "wall- to-wall" subdivision, where every

portion of each parcel is developed into yards, roads, and driveways.39 Many property

owners object to large lot zoning because, they allege, “low- and moderate-income

homebuyers are excluded from this sector of the housing market”. 40 Some critics have

dubbed large lot zoning “snob zoning”.41

3. Cluster Zoning

Cluster zoning utilizes development on part of a property while preserving the

remainder for open space and/or agricultural uses. Cluster zoning requires more

creativity in urban site design and protects on-site amenities or environmentally sensitive

areas. 42 Cluster zoning is also known as “open space zoning” or “density zoning,” and

cluster subdivisions are sometimes known as “cluster developments”, “open space” or

“open land subdivisions”. 43 Cluster zoning may allow variable lot sizes, setbacks,

landscaping, densities, and design standards.

Clustering may be accomplished by the use of a particular zoning district that

establishes a fixed or sliding scale area-based dwelling unit allocation and requires

clustering on a portion of the site. Clustering can be used in conjunction with existing

zoning and allowed as an optional or density bonus. 44 For example, in the Hammocks, a

clustered residential development in Florida, single-family housing was built by creating

green spaces within neighborhoods and a greenway system between the neighborhoods

37 METROPOLITAN MIAMI-DADE COUNTY PLANNING DEPARTMENT , supra note 31, at 73.

38 TOM DANIELS, WHEN CITY AND COUNTY COLLIDE: MANAGING GROWTH IN THE METROPOLITAN FRINGE

217 (Island Press 1999).

39 Jackson Meadow, Ecology of the Cluster Model, available at

http://www.jacksonmeadow.com/brochure/brochure/brochure_3.htm (August 1, 2002).

40 The Greenbelt Education Project, How to Keep the Country in the Lowcountry, available at

http://www.charleston.net/org/greenbelt/tools.html (August 1, 2002).

41 Executive Order 418 Housing Certification Commonwealth Of Massachusetts Fy2002, available at

http://www2.massdhcd.com/e418portal/ CommReport02.asp?MNO=317&FY=2002 (August 2, 2002).

42 METROPOLITAN MIAMI-DADE COUNTY PLANNING DEPARTMENT , supra note 31, at 77.

43 AMERICAN FARMLAND TRUST , supra note 30, at 33.

44 METROPOLITAN MIAMI-DADE COUNTY PLANNING DEPARTMENT supra note 31, at 77.

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and lakes. The Hammocks was also able to double their gross density to an average net

density of 11.5 units per acre.45

Cluster zoning may require the landowner of a tract of land to identify the

building lots and the open space to be preserved, or it may simply require that a certain

percentage of land remain as open space dedicated to agricultural uses. The protected

land is usually owned and maintained by a homeowners association. Permitted land uses

are either identified in the existing zoning or limited by cluster development regulations.

For example, one model ordinance permits residential uses such as clustered single

family houses, single family farmstead dwellings, and community living arrangements

and agricultural/open space uses such as farming (i.e. crops, farming, and livestock),

Christmas tree farming and sales, and passive recreational spaces (i.e. wildlife sanctuaries

and nature preserves).46 Other communities, like Larimer County, Colorado, offer a

system of incentives and benefits that gives local administrators and land owners

flexibility to tailor land use requirements to the particularities of individual parcels of

property. 47

However, the most effective clustering ordinances are those that are mandatory. 48

When clustering and open space preservation are left optional, few developers take

advantage of the approach. Most continue as they have always done: creating

checkerboards of house lots and streets. This means that even though the clustering

option is in the zoning ordinance, it remains essentially unused. The community is still

left with conventional development patterns which destroy agricultural areas.49

Though cluster zoning can keep land available for agriculture or open space, it is

generally not a viable technique for commercial agriculture.50 The protected land is

generally owned by a homeowners association, and while homeowners may lease it back

to local farmers, some residents may object to allowing agricultural production because

of noise, dust, and odors related to commercial farming.51 Utilization of right-to-farm

laws (discussed below) will help. One solution creates an ordinance that requires

homeowners to lease the land back to local farmers, while limiting the type and scale of

agriculture on the property, or ensuring that farmers who sell development rights to

homeowners retain title to continue farming.52 In general, cluster zoning has been used

most successfully to preserve open space or to create transitional areas between farms

and residential areas.53

45 Sprawlwatch, Land Use Planning and Zoning, available at

http://www.sprawlwatch.org/landuseandplanning.html (August 1, 2002).

46 Southeastern Wisconsin Regional Planning Commission, Model Zoning Ordinance for Rural Cluster

Development, available at http://www.sewrpc.org/modelordinances/cluster_ordinance.pdf (August 1,

2002).

47 E. Tyson Smith & Philip Moffat, An Analysis of the Development and Planning Alternatives to Protect

the Character of Eastern Sarasota County while Minimizing Adverse Impacts on Taxpayers 32 (January

2000) (unpublished manuscript, on file with the University of Florida Conservation Clinic).

48 Id. at 32 (referencing SAMUEL N. STOKES, ET AL., SAVING AMERICAS COUNTRYSIDE 182 (2nd Ed. 1997)).

49 Randall Arendt, “Open Space” Zoning: What it is and Why it Works, 5 PLAN. COMMISSION J. 4 (1992),

available at (http://www.plannersweb.com/articles/are015.html#mandatory) (August 2, 2002).

50 AMERICAN FARMLAND TRUST , supra note 30 at 33.

51 Id.

52 Smith, supra note 47, at 31.

53 AMERICAN FARMLAND TRUST , supra note 30 at 33.

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Critics of cluster zoning argue that it actually results in “clustered sprawl”.54

Critics also argue that cluster zoning is environmentally unsound because cluster

development works best with urban infrastructure, but the remote location requires onsite

septic tanks. Failing septic systems require the extension of water and sewer lines,

which opens farmland up to more development.55 Finally, cluster development sometimes

is criticized based on the simple presumption that residential and agricultural uses cannot

exist in close proximity without unacceptable conflict.56 Clearly, as mentioned above,

certain conflicts must be addressed. Crop dusting and spraying, for example, require that

significant buffers between crops and clustered homes be maintained.

Critics of clustering worry that this technique will cause loss of rural character.

However, subdivisions designed with this concern in mind can mitigate, if not eliminate,

this concern. For example, instead of having separate driveways onto the arterial roads,

creating a more urban feel, a subdivision could be designed so the entire tract is set back

from the main road, and only one access point exists to the road, with houses accessing a

loop or networks of small streets. Those streets should be gravel and narrower than

traditional urban subdivisions to create a rural neighborhood feel.

Subdivisions also should be buffered from the street with extensive landscape

material; perhaps so well-buffered that passing motorists are not aware that the houses

exist. If there are wooded or heavily landscaped areas, the cluster should locate within

the wooded areas

The design of the building within the community can also reduce any concerns.

Houses can be designed to connote a small town feeling instead of the spreading suburbs.

Architects may design homes with human proportions, local architectural styles, local

materials, and other techniques to connect the house to the particular community.57

Clustered developments are allowed in Miami-Dade County under its Zoning

Code.58 Cluster developments must be single-family dwelling units and common areas

are allowed within the zone, including any associated structures.

4. Buffering

Buffering is the physical separation of farms from incompatible uses, usually by

landscape, open space, or other barriers. Buffers are narrow bands of land planted with

permanent vegetation that are located around and in areas of intensive agricultural

production. 59 Buffers help safeguard farms from trespassers and protect adjacent

54 DANIELS, supra note 38, at 219.

55 Id.

56 Id. at 219.

57 RANDALL ARENDT ET AL., RURAL BY DESIGN: MAINTAINING SMALL TOWN CHARACTER 62 (Planners

Press 1994).

58 MIAMI-DADE COUNTY ORDINANCES 33-284.6-.9.

59 National Conservation Buffer Council, Conservation Buffers: Showing Stewardship, Protecting

Productivity, available at http://www.buffercouncil.org/ (August 1, 2002).

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homeowners from the externalities of commercial farming.60 Field borders, grass buffers,

contour grass strips, grassed waterways, and vegetative borders, are several types of

buffers which serve to minimize conflicts between residential and agricultural users. 61

Buffers are advantageous for many other reasons. Buffers create havens for

wildlife. Buffers are visible, tangible examples of land stewardship.62 Buffers enhance

quality of life by providing open space in a community and enhancing the value of land

conservation. Environmentally, buffers slow down water runoff from fields and block

suspended chemicals, pathogens, and sediment from reaching water bodies.63

Buffering places the responsibility for construction and maintenance upon the

farm owner, the adjacent homeowners or a third party. The Georgia Model Code, for

example, requires any non-agricultural use locating next to an agricultural use to provide

a 150 foot agricultural buffer.64 The buffer must consist of trees, hedges, landscaping,

and naturally occurring elements as long as there is a semi-opaque screen between the

agricultural and non-agricultural uses.65 Many California localities similarly require

agricultural setbacks. In San Luis Obispo County the buffer is mandatory and ranges

from 100 to 800 feet depending on the type of agricultural use to be protected. In

Sacramento County the buffer is mandatory and generally requires a physical separation

of 300 to 500 feet. In Stanislaus County the buffer is mandatory and can be

topographical, vegetative or other and is determined on a site-by-site basis.66

Some buffers are not mandatory but are farmer initiated. In Suffield, Connecticut

an individual farmer may request a buffer with a width of 30 to 100 feet. The buffer is

located on the parcel to be developed and maintained by the developer. The law also

requires that lot owners be notified that they are responsible for buffer maintenance and

that subdivision plans include a provision for active agriculture and recognize agricultural

practices that may annoy or irritate residents.67

The Natural Resources Conservation Service (NRCS), of the United State

Department of Agriculture (USDA), promotes the development of buffers by farmers

themselves. The NRCS leads the National Conservation Buffer Initiative, a multiyear

effort undertaken by the USDA. The goal of the initiative is to encourage the use of

conservation buffers by farmers, ranchers, and other landowners as a means of improving

soil, water, and air quality while enhancing fish and wildlife habitat, and adding to the

60 AMERICAN FARMLAND TRUST , supra note 30, at 318.

61 National Conservation Buffer Council, Conservation Buffers: Showing Stewardship, Protecting

Productivity, available at http://www.buffercouncil.org/ (August 1, 2002).

62 Id.

63 Id.

64 Georgia Department of Community Affairs, Model Code: Alternatives to Conventional Zoning:

Agricultural and Buffer Requirements §4-3 (April 2002), available at

http://www.dca.state.ga.us/planning/ModelCode/4-3AgriculturalBuffer.pdf (August 1, 2002).

65 Id.

66 Farmland Preservation Report, Farmland Programs Neglect Buffer Protections, Volume12, Number 4,

(February 2002).

67 Id.

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beauty and diversity of farms and ranches across the country. 68 Farmers can receive

assistance through the Conservation Reserve Program and other federal, state, and local

government programs to help with the cost of implementing buffer practices. These other

programs include the Environmental Quality Incentives Program, Wildlife Habitat

Incentives Program, Wetlands Reserve Program, and Stewardship Incentive Program. 69

A significant challenge with buffers is enforcement. Though ordinances may

require buffers, they are not always enforced. Buffering ordinances can be effective as

long as local government has subdivision review authority to impose the buffer

requirement and that they are enforced once in place. Placing the buffer restriction in the

landowner’s title will assure adequate legal notice to the individual land owner

responsible.70

Successful buffer ordinances cannot be standard; each buffer must be site based

and locally determined. A draft report from a California research group indicates that in

some cases structural barriers are actually more effective than swathes of open space.

Under this scenario, an ordinance must determine the structural barrier and establish a

source of payment for repairs and maintenance 71

5. Overall Benefits and Drawbacks of Agricultural Zoning

Overall, the aforementioned zoning techniques are an inexpensive way to protect

large areas of agricultural land because little public expenditure is necessary to

implement zoning ordinances. Communities also favor agricultural zoning ordinances

because they are easy and quick to implement as compared to TDR or PDR programs

(discussed below) and easy to explain to the public who are accustomed to zoning

ordinances. They also separate farms from non-agricultural land uses, and reduce the

likelihood of conflicts between farmers and non- farming neighbors. Finally, agricultural

zoning is flexible in that it can change wit h the economic or political climate.72

Critics of agricultural zoning suggest that such programs are not permanent.

While flexibility may be a benefit it is also a drawback because large agricultural parcels

may quickly be converted to developable parcels. Similarly, agricultural preservation

ordinances do not prevent annexation by municipalities (unless annexation is forbidden

on agricultural lands). Many successful agricultural zoning programs have a mandatory

deed restriction or easement requirement to prevent conversion when annexation occurs.

These ordinances also generally decrease land values, which decreases a farmer’s equity

in land. For this reason, many farmers oppose these programs. Finally, such programs

may be difficult to monitor and enforce on a day-to-day basis.73

68 United State Department of Agriculture, Farm Preservation Report: Buffers, Common-Sense

Conservation, available at

http://www.nrcs.usda.gov/feature/buffers/BufrsPub.html#InitiativeBuff_7Anchor (August 1, 2002).

69 Id.

70 Farmland Preservation Report, supra note 66, at 2.

71 Id. at 3.

72 AMERICAN FARMLAND TRUST , supra note 30, at 50.

73 Id.

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B. Non-Zoning Techniques

1. Right-to-farm Laws

Since 1963, every state in the nation has enacted a right-to-farm law. 74 Right-tofarm

laws are state laws or local ordinances that protect farmers and farm operations from

public and private nuisance law suits.75 The right-to-farm laws strengthen the legal

position of farmers against nuisance suits by their neighbors, and protect farmers from

anti-nuisance ordinances and unreasonable agricultural regulations.76 Right-to- farm laws

do not protect farmers from state and federal pollution and safety laws, but do underscore

the legitimacy of farm uses.77

State right-to- farm statutes can be broken into three groups. First, general rightto-

farm statutes provide that a farming operation cannot be declared a nuisance if it was

not a nuisance at the time the operation began. 78 This type of statute is also termed a

“coming to the nuisance” statute. It gives farmers a legal defense from residents moving

to the area who claim to be harmed by the off-site impacts of agriculture.79 The second

type of statute protects specific types of agriculture such as the cultivation of land,

production of crops, and raising of poultry. 80 These types of statutes protect farmers from

unreasonable local regulations. The third type of statute protects farmers and food

companies from suits over food safety. 81 Florida’s Right-to-Farm Act, which applies in

Miami- Dade County, is a general right-to- farm law.

Right-to-farm laws have not been extensively litigated, but this is likely to change

as the urban fringe creeps nearer to farmland and new residents file suits based on

trespass rather than based on nuisance.82 Plaintiffs may still file a nuisance suit against a

farmer regardless of the existence of right-to-farm laws. Though the plaintiff has a slim

chance of winning, the cost and aggravation of the suit may be detrimental to the farm.83

Thus, some statutes, for example Michigan, require plaintiffs to pay farmer’s costs in an

unsuccessful nuisance suit,84 while states such as Delaware, Iowa, Kentucky, Missouri,

New Mexico, South Dakota, and Wisconsin allow farmers to recover only for frivolous

suits.85

74 Id. at 169.

75 A public nuisance involves actions that injure the public at large, while private nuisances interfere with

an individual’s use of their property.

76 AMERICAN FARMLAND TRUST , supra note 30, at 169.

77 DANIELS, supra note 38, at 220.

78 DAVID L. CALLIES, ROBERT H. FREILICH, & THOMAS E. ROBERTS, CASES AND MATERIALS ON LAND USE

662 (3rd ed. 1999).

79 DANIELS, supra note 38, at 175 (citing NEIL HAMILTON, A LIVESTOCK PRODUCERS LEGAL GUIDE TO

NUISANCE, LAND USE CONTROL AND ENVIRONMENTAL LAW (Drake University Agricultural Law Center

1992)).

80 FREILICH, supra note 29, at 287.

81 Id.; Melody Petersen, Farmers’ Right to Sue Grows, Raising Debate on Food Safety, N.Y. Times, June 1,

1999 at A-1, col. 1.

82 DANIELS, supra note 38, at 150.

83 Id. at 151.

84 Id.

85 Id. at 176-79.

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Right-to-farm laws are effective when metropolitan areas begin to encroach on

outlying farm communities.86 They make urban dwellers that want a rural lifestyle

rethink their decision when animal waste, airborne pollution, odors, slow-moving farm

machines on roads, and roosters crowing at the crack of dawn disturb their “rural

tranquility”.87 Without such laws, public law nuisance suits may succeed. As a political

matter these ordinances also encourage elected officials to minimize ordinances that are

intrusive on farming. Nonetheless, these laws do not prevent the ultimate problem of

incompatibility of uses, which must be addressed through strict environmental

enforcement and well-designed agricultural districts. Another resolution is to allow for

payment of damages instead of cessation of activities.88

One County Commissioner in Larimer County, Colorado suggested a creative

“right-to- farm” provision. He drafted the Code of the West, which provides advice for

people thinking of buying land in the rural part of Larimer County’s metropolitan region.

The introduction says:

It is important for you to know that life in the country is different from life in the

city. County governments are not able to provide the same level of service that

city governments provide. To that end, we are providing you with the following

information to help you make an educated and informed decision about whether

to purchase rural land.89

The Code of the West then goes on to describe the realities of country life,

including slow tractors, that some lots are not buildable, that farmers work around the

clock and that animals and manure can cause objectionable odors.90

Right-to-farm laws strengthen growth management techniques such as clustering.

In a recent case, Whitted v. Canyon County Board of Commissioners,91 the Iowa Supreme

Court concluded that right-to-farm laws encourage full and complete use of agricultural

land, yet are still compatible with growth management techniques. A farmer proposed a

small subdivision on a portion of his farm with rocky, poor farmland. He intended to

continue farming the rest of the land. Neighbors appealed the approval of the subdivision

claiming it would deprive them of full use of their agricultural land. The court disagreed

and concurred with the county’s land use board, stating “[by] allowing development…the

development pressure on land more conducive to agriculture would be lessened.

Further…requiring deed restrictions and marketing disclosures would aid in preserving

the agricultural nature of the surrounding area.”92

Section 33-28.1 of the Miami-Dade County Zoning Code requires agricultural

disclosures for any land that is either designated Agriculture (AU), or zoned Interim (GU)

(outside UDB only) and determined to be subject to AU trends of development or located

within the UDB and abuts any AU zoned parcel. The seller of such property must inform

86 FREILICH, supra note 29, at 287.

87 Id.

88 See e.g. Boomer v. Atlantic Cement Co., Inc., 40 N.Y.S.2d 97 (N.Y.Sup. 1972).

89 DANIELS, supra note 38, at 275.

90 Id. at 275-78.

91 44 P.3d 1173 (Idaho 2002).

92 Id. at 1178.

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the buyer that the land or adjacent land is zoned agricultural and that there are associated

noises, pollutants, and activities that might be offensive to the buyer.

The Florida Right-to-Farm-Act prohibits farms in operation for a year or more

from being declared either a public or private nuisance, except under very limited

circumstances. In order to enjoy protection under the Act, however, the farm must

continue to comply with “generally accepted agricultural and management practices”. 93

The Second District Court of Appeals for the State of Florida found that the right-to-farm

law was “intended to preserve productive land for agricultural purposes and to protect the

established farmer from demands of sprawling urban development.”94 However, very

little litigation has occurred pursuant to this law since its original adoption in 1979.

2. Agricultural Districting

Agricultural districting is different than agricultural zoning. Zoning only

addresses particular land uses and is one tool that can be used in an agricultural district.

Agricultural districting, on the other hand, allows farmers to form special areas

where commercial agriculture is encouraged and protected, establishing a broad array of

measures to encourage and protect agricultural activity in the district.95 Protective

measures may include bans on local government laws that restrict farming, enhanced

protection from private nuisance lawsuits, eligibility for differential tax assessment,

limiting non-farm development around active agricultural areas and conservation

easement programs.96 Pennsylvania created one of the most effective agricultural

districting programs in the country. The Pennsylvania law identifies five purposes for

agricultural districting: “(1) Encourage landowners to make a lo ng term commitment to

agriculture by offering them financial incentives and security of land use; (2) Protect

farms from incompatible uses; (3) Assure permanent conservation of agricultural land to

protect the agricultural economy; (4) Provide compensation to landowners for

development rights; and (5) Leverage state funds for the purchase of agricultural

conservation easements and protects [sic] the public investment in easements.”97

Agricultural districting programs are generally state-level programs. To date,

sixteen states have enacted agricultural district laws.98 Generally, state statutes establish a

process for identifying agricultural districts and designate geographical areas for long

term agriculture. State statutes also include a combination of measures and management

tools, as described above, to protect farmland. The requirements and provisions of the

programs differ greatly, but general conclusions can be drawn. The programs are flexible

and local in nature, stabilize the land base at a low public cost, provide multiple benefits

93 Fla. Stat. 823.14.

94 Pasco County v. Tampa Farm Service, Inc., 573 So. 2d 909 (2nd DCA 1990).

95 AMERICAN FARMLAND TRUST, supra note 30, at 197; METROPOLITAN MIAMI-DADE COUNTY PLANNING

DEPARTMENT , supra note 31, at 94.

96 Id.

97 AMERICAN FARMLAND TRUST , supra note 30, at 201.

98 Id. at 197.

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to farmers, help protect large blocks of land, and enrollment is voluntary. 99 In contrast,

drawbacks associated with agricultural districting include the fact that sanctions for

withdrawing land are minimal and do not deter conversion; the limits on non-farm

development may not prohibit the development of urban infrastructure in agricultural

areas; in some states, the benefits are not a strong enough incentive for farmers to enroll;

and, in others, the procedure for creating the districts is long and cumbersome.100 Florida

does not have a similar state law, but that does not preclude Miami-Dade County from

implementing some agricultural districting measures typical in state- level programs.

New York has one of the most successful agricultural districting programs in the

nation, in part because it is aimed at preserving farmland through maintaining and

fostering farming itself. By granting a series of benefits that provide more favorable

social and economic conditions, the program encourages an environment that is more

beneficial for agriculture. Support from elected officials also has helped to create an

agriculture- friendly atmosphere. For example, the legislature passed an act that declares

agricultural land to be an “environmental resource of major importance”.101

In addition to creating an agricultural districting program, the New York program

also includes provisions that prohibit local nuisance ordinances from interfering with

normal farm operations; requires agency review of development which induces

infrastructure expansion; requires alternative consideration for public development

proposals that bring agricultural lands into the hands of the municipality through eminent

domain; allows for tax incentive programs; and directs all state agencies to maintain

viable agricultural districts.102

3. Land Evaluation Systems

The land evaluation and site assessment system (LESA) was launched in 1981 by

the U.S. Soil Conservation Service to make objective ratings of the agricultural suitability

of lands against demands for other uses.103 LESA effectively rates a tract’s potential for

agriculture, as well as other social and economic factors.104 Though the federal

government developed LESA, state and local governments have adopted it to meet their

specific needs, and it has become part of many governments’ land use planning tools.105

LESA enables the planning of water, sewer, and transportation projects or the creation of

agricultural districts, and the assessment and review of environmental impacts. 106

99 Shirley Sternamen & Elizabeth Mumby, New York State: Protecting Farming with Agricultural Districts

77, 80, in PLOWING THE URBAN FRINGE: AN ASSESSMENT OF ALTERNATIVE APPROACHES TO FARMLAND

PRESERVATION (Hal Hiemstra & Nancy Bush wick, eds., 1989).

100 Id.

101 Id. at 86.

102 Id. at 80; see also N.Y. AGRI. & MKTS. LAW § 300 et. Seq. (1988 Cum. Supp.).

103 Frederick R. Steiner, Introduction, in A DECADE WITH LESA: THE EVOLUTION OF LAND EVALUATION

AND SITE ASSESSMENT 13 (Frederick R. Steiner, James R. Pease & Robert E. Coughlin eds., 1994).

104 Id.

105 Id.

106 Lloyd E. Wright, The Development and Status of LESA, in A DECADE WITH LESA: THE EVOLUTION OF

LAND EVALUATION AND SITE ASSESSMENT 36, supra note 103.

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LESA’s land evaluation and site assessment elements form a two-part system that

assists in the implementation of the Farmland Protection Policy Act (FPPA), selecting

appropriate lands to be included in the program, and establishing minimum parcel sizes

for farm subdivisions in agricultural districts.107 The land evaluation part of LESA is

usually designed by the federal Soil Conservation Service (SCS) and local Soil and Water

Conservation Districts (SWCD), and implemented by a local committee generally

comprised of a district conservationist, a cooperative extension representative, SWCD

directors, farmers, planners, local agricultural officials, and others who have knowledge

of the land resources of the area.108

Local officials or a locally appointed site assessment committee usually design

the site assessment component.109 Site assessment factors include parcel size; on-farm

investment; and characteristics external to the parcel of land, such as nearby land uses,

zoning, and other farmland protection measures.110 A local committee may include local

planners, members of the planning commission, SWCD directors, a cooperative

extension representative, building industry representatives, recreational representatives,

public interest groups, concerned citizens, and other government representatives

interested in agricultural preservation. 111

LESA is a flexible system, designed to accommodate differences among states,

counties, or areas. Specific systems should be based on existing knowledge of the area,

local soil surveys, land use plans, policies, and programs. LESA may be applied

consistently to all lands or on a case-by-case basis.112 LESA may be used to accomplish

the following objectives:113

i. Select lands to be part of a TDR or PDR program;

ii. Implement the federal Farmland Protection Policy Act;

iii. Choose farm units to be included in agricultural preservation programs;

iv. Determine appropriate lot size for subdivisions in agricultural districts;

v. Plan water, sewer, and transportation projects or the creation of

agricultural districts;

vi. Determine the need for an agricultural preservation program and the types

of programs to be used;

vii. Assess and review environmental impacts; and

viii. Develop guidelines under which agricultural land conversion to nonagricultural

uses should be permitted.

A 1990-91 study identified 212 local and state governments in 31 states as active

or former users of LESA. 114 Of these 212 jurisdictions, 138 local and state governments

were still using the system in 1994. Those who abandoned the sys tem found it too

107 FREILICH, supra note 29, at 286.

108 WRIGHT, supra note 106, at 35.

109 Id.

110 Id.

111 Id. at 35-36.

112 Id. at 36.

113Id.

114 Id. at 58 referencing Steiner, F., J Pease, R. Coughlin, J. Leach, C. Shaw, A. Sussman, and J. Pressley.

Agricultural Land Evaluation and Site Assessment: Status of State and Local Programs (The Herberger

Center 1991).

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complicated or time consuming; some noted a lack of interest or support by landowners

or planners.115 The unreliability may be attributed to technical problems with a particular

LESA system, staffing inadequacies, or local political factors.116 Seventy- nine percent of

respondents were satisfied with the LESA system.

Miami-Dade County does not have a LESA program, but other counties in Florida

– Highlands, Marion, and Pasco, for example – have utilized LESA. Although soil

quality, a major factor under LESA, is not as relevant in Miami-Dade County, other

LESA criteria will be useful should the County adopt prioritization criteria to implement

the preferred development scenario.

C. Land Acquisition Programs

1. Conservation Easements

A conservation easement (or conservation restriction) is a voluntary legal

agreement between a landowner and a land trust or government agency that permanently

limits uses of land in order to protect its conservation values. It allows a landowner to

continue to own and use their land and to sell it or pass it on to heirs.117 Each easement is

tailored to meet the owner’s personal management objectives and goals for the property.

In essence the landowner sells his or her right to develop the land to a

conservation organization or governmental entity. Current uses, including residential and

recreational uses, agriculture, forestry, and ranching can continue, although the easement

might require the protection of some environmental and aesthetic qualities of the

property. 118

Placing an easement may result in property tax savings and can be essential for

passing land on to the next generation. By removing the land's development potential,

the easement lowers its market value, which in turn lowers estate taxes. Whether the

easement is donated during life or by will, it can make a critical difference in the heirs'

ability to keep the land intact.119

2. Purchase of Development Rights

In a typical purchase of development rights (PDR) program, the government

purchases the owner’s right to develop specific parcels of land for managerial purposes,

leaving the owner all the rights of ownership.120 One form of PDR commonly used for

agricultural preservation is a purchase of conservation easements (PACE).121 Landowners

115 Id. at 59.

116 Id.

117 Land Trust Alliance, Conservation Options for Landowners: Conservation Easements, available at

http://www.lta.org/conserve/options.htm (August 1, 2002).

118 University of Florida, Conservation Easements, available at

http://www.sfrc.ufl.edu/Extension/ffws/ce.htm (August 2, 2002).

119 Id.

120 See Thompson, Purchase of Development Rights: Ultimate Tool for Farmland Preservation?, 12

ZONING & PLAN. L. REP. 153 (1989).

121 The term PDR will encompass PACE for the remainder of this paper.

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sell conservation easements to governments or other private conservation agencies. The

price of the development right is generally equal to the diminution in the market value of

the land resulting from the removal of the development rights, and thus is the difference

between the value of the land for agricultural use or open space and the land’s

development value.122 In return for the payment, the landowner agrees to use the land for

open space or agriculture in perpetuity, though some programs allow termination of the

condition under certain restrictions.123

PDRs are designed to be voluntary. Offering an incentive to land owners may

convince them to resist selling their land for a potentially high price to subdivision

developers. In short, purchasing development rights is cheaper than buying the land in

fee simple.

State and local governments may cooperate on PDR programs or work

independently. Some states have enacted PDR programs that are funded, implemented,

and administered by state agencies. Other states fund the purchase of land by either local

governments or non-profit organizations.124 Cooperative programs are advantageous

because they allow the state to set broad policies and implement regional planning

strategies. Local governments, with their specific knowledge of the area, then identify

land suitable for the PDR program and monitor the land once the easements are in

place.125 Cooperative programs generally increase the level of funding available for

PDRs.

According to the American Farmland Trust, PDR programs are very popular with

farmers, yet the supply of money has lagged behind the supply of easements offered by

farmers. PDR programs are popular with farmers because they offer enticing incentives.

PDR programs increase the availability of real capital to farmers without mortgaging

land; lower real property taxes due to the decrease in the value of the land once the

development rights have been sold; and there are potential estate or inheritance tax

benefits.126 PDR programs offer a more permanent solution than zoning and avoid the

takings challenges that hamper zoning efforts.127

On the downside, some landowners reject PDR programs because they are

perceived as “tying the hands” of the landowners’ heirs, who may wish to sell the land

for development value.128 In addition, although buying development rights is cheaper

than buying the property outright, a PDR program is still cash intensive and communities

may reject PDR programs if they require local monetary support in the form of

development fees or taxes. In communities where taxes and fees are already levied for

schools, public safety, parks, infrastructure, and community programs, agricultural

122 FRANK SCHNIDMAN, MICHAEL SMILEY & ERIC G. WOODBURY, RETENTION OF LAND FOR AGRICULTURE:

POLICY PRACTICE AND POTENTIAL IN NEW ENGLAND 18 (Lincoln Institute for Land Policy 1990).

123 See, e.g., MASS. ADMIN. CODE Tit. 330 Section 22.10 or RI Gen Laws Section 42-82-5e.

124 See, e.g.,: Frank Schnidman, supra note 122, Rhode Island 204-5, Vermont 141-43, Connecticut 186,

Maine, 306 and Massachusetts 88-91.

125 Id.

126 PATRICIA E. SALKIN, ZONING AND LAND USE CONTROLS § 56.04[2] (2000).

127 DANIELS, supra note 38, at 223.

128 SALKIN, supra note 126, at § 56.04[2].

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preservation may fall by the wayside unless there is heightened community awareness of

the necessity of preserving agricultural lands.129

Successful PDR programs must be carefully designed and include a set of criteria

to determine from which lands the development rights should be purchased. The criteria

must take into account the location and surrounding uses of the land. PDR programs

make sense if hundreds of acres can be preserved (either through contiguous smaller

parcels or a few large parcels) because it makes it more likely that commercial farms will

be successful.130 If only smaller amounts of farmland can be preserved, the adjacent land

may be a magnet for housing developers who market “rural lifestyles” and the conflict

between farming and residential uses will be maximized.131 Additionally, the costs of

land in PDR programs must be reasonable and should be balanced against the likelihood

that land will remain in viable agricultural production for a certain amount of time.132 At

a high expense per acre, little farmland will be saved at enormous costs, and even then

the aforementioned issue arises of whether the farm will be big enough to sustain itself.133

Although Miami-Dade County has a viable “transferable development rights”

program (discussed below), known as “severable use rights” it does not have a PDR

program. The advantages of a PDR program are that the governing agency – or a

designated land trust – has greater control over which lands are identified for

preservation. The challenge, of course, is generating the funds to purchase development

rights. However, in communities that are experiencing a decrease in agricultural viability

and simultaneous increase in urban growth pressure, the ability to affirmatively secure

open space is critical to success. As is discussed in Task 2(c), this has proven to be the

case in many communities around the country that have successfully preserved

significant agriculture and open space lands. The Task 2(c) report explores five of these

communities and suggests ways that Miami-Dade County might successfully implement

similar regulatory approaches.

3. Land Banking

Land banking, also referred to as advance acquisition, is a technique where land is

purchased before it is ready to be developed.134 This requires the establishment of land

banks for the purpose of acquiring lands in urban areas where expansion is expected to

ensure that it is developed at the most advantageous time for the community.135 The land

banks are governmental units that could either purchase agricultural land in fee simple

and lease it back to farmers or only purchase the development rights.136

129 RICK PRUETZ, SAVED BY DEVELOPMENT: PRESERVING ENVIRONMENTAL AREAS, FARMLAND AND

HISTORIC LANDMARKS WITH TRANSFER OF DEVELOPMENT RIGHTS 69 (Arje Press 1997).

130DANIELS, supra note 38, at 224.

131 Id.

132 SALKIN, supra note 126, § 56.04[2].

133 DANIELS, supra note 38, at 224; see also the discussion of Suffolk County in Task 2(c).

134 DANIELS, supra note 38, at 171.

135 FREILICH, supra note 29, at 290.

136 FREILICH, supra note 5, at 42.

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Land banks are advantageous because they allow for better control over timing

and type of development, and discourage land speculation and leapfrog development.137

Also, by giving public officials a more personal interest in property and its regulation, it

helps promote sounder planning practices such as unrestricted, flexible comprehensive

plans. A land bank is flexible because it controls the land being sold and bought.138

A successful land bank must have the power to purchase property and condemn

land.139 A land bank should be granted the power to hold land for an indefinite amount of

time so that the land bank can pace development appropriately. A land bank must also

have the power to borrow money, issue bonds, and obtain government aid.140 The major

drawback to this technique is the expense.

The legality of land banking has been questioned, and the U. S. Supreme Court

has not established a bright line rule.141 Both state and federal courts have declared that if

the purpose of condemning the land has a reasonable relationship to the purpose of

protecting open space and environmental lands, then the taking is for a public use and

legitimate.142 Land banking is more likely to be upheld by courts than other planning

controls because it is a reasonable means of fulfilling a public purpose, particularly where

purchases are made consistent with the explicit policies of an adopted comprehensive

plan.

4. Transfer of Development Rights

Transfer of development rights (TDR) programs – called “Severable Use Rights”

in Miami-Dade – allow for planning on an area wide basis by allowing landowners in

restricted areas (“sending areas”) to transfer densities and other development rights to

landowners in areas appropriate for higher density development (“receiving areas”).143

Landowners in receiving zones are allowed to develop their land but only if they

purchase development rights from designated sending areas. Thus, development is

directed away from agricultural or environmentally sensitive lands to areas better

equipped to deal with heavy development.144 TDR programs give governments an

alternative to purchasing land outright and ameliorate the harshness of restrictive

zoning.145

TDR programs are popular with citizens and governments because the goal is to

have an “everyone wins” outcome.146 The sending site landowner is able to continue

farming without development pressures but with the benefits from the sale of the rights.

137 DANIELS, supra note 38 at 171.

138 FREILICH, supra note 29, at 291.

139 Id.

140 Id.

141 Id. at 292.

142 Id.

143 Id at 288.

144 Andrew J. Miller, Transferable Development Rights in the Constitutional Landscape: Has Penn Central

Failed to Weather the Storm? 39 Nat. Resources J. 459, 467.

145 FREILICH, supra note 29, at 288.

146 PRUETZ, supra note 129, at 3.

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The receiving site landowner is able to build at a greater density, and realizes the market

value of their land. The community benefits by preserving farmland without incurring

significant expense.147 Local governments particularly find these programs attractive

because:148

· They encourage increased densities in developed areas making full use of public

infrastructure;

· Increased density works together with the need to provide a fair share of

affordable housing;

· Often, private developers pay landowners, so no public monies are spent;

· Landowners receive compensation for the restrictions placed on their lands, thus

decreasing the likelihood of successful taking claims; and

· Local government can preserve a significant amount of land while funneling

growth into desired areas.

TDR programs are a market-based tool, thus municipalities must be certain there is a

market for the development rights being bought and sold. A municipality must, through a

comprehensive planning process, determine how many development rights are to be

bought and sold and where. A TDR program must encourage sales that benefit the entire

community, not just a few select landowners.149 The number of rights to be bought or

sold should be based on ecological and populations concerns; the more sprawling the

community, the more rights are required.150

Successful TDR programs include the following:

· Encouragement of sending area landowners to sell their development rights

through development restrictions, development constraints, and transfer ratios;151

· Encouragement of receiving area landowners by allowing the highest density

appropriate, exemption from certain fees, and exemption from certain

development standards;

· A clear separation between resource lands, existing development, and properties

planned for development;152

· An active real estate market to ensure buying and selling of rights;153

· Fast, easy and certain TDR approvals, including certain costs, and a clear,

discernible, and transparent process154

· A TDR bank or revolving fund that can help set a floor price for TDRs155

· Provision of public staff for implementation;

· Monitoring of program performance; and

· A flexible program that can be refined as needed.

TDR programs may be mandatory or voluntary. Mandatory programs are

designed to prevent fragmentation of farmland in a way that protects landowners’

147 Id.

148 DANIELS, supra note 38, at 225.

149 Id. at 51; FREILICH, supra note 29, at 289.

150 FREILICH, supra note 29, at 289.

151 PRUETZ, supra note 129, at 51.

152 DANIELS, supra note 38, at 226.

153 Id.

154 PRUETZ, supra note 129, at 58.

155 Id. at 61.

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equity. 156 Mandatory programs often feature dual zones with the down zoning of a

sending area and the designation of a receiving area. Landowners in the sending zones

are not required to sell their development rights, but may as a method of receiving

compensation for the down zoning. Similarly, receiving area landowners must buy

development rights to recognize the full economic potential of their land.157 Mandatory

development restrictions may include virtual prohibition of non-farm development in

agricultural areas through zoning, large minimum lot size, or restrictive requirements for

infrastruc ture.158 Local governments implementing mandatory programs must ensure that

adequate public facilities will be available in the receiving areas.159

Voluntary TDR programs allow landowners in sending areas to sell their

development rights to a party in a receiving area in lieu of development in the sending

area. There is no reduction in density in the sending area.160 Landowners in sending

areas may choose to develop parts of their property and sell off development rights on

another part, but this may lead to a large number of rural residences amid farmlands.161

Voluntary programs may be more attractive to local governments because they are less

politically controversial.

Successful TDR programs use a revolving fund where purchased development

rights are sold on the open market and the funds are reinvested in the purchase of new

development rights that will be banked. Communities that invest funds in areas other

than the purchase of development rights jeopardize their TDR program because only a

finite amount of money is available to purchase development rights.

However implemented, TDR programs must be designed to withstand legal

challenges. First, as discussed above, a market for development rights is critical. The

market will dictate whether a sending area is appropriate for down zoning or whether

such down zoning would leave no economically viable use for those property owners.

Designation of sending and receiving districts may also generate significant debate

(density in the sending areas is low, while density in the receiving areas is too high).

Next, zoning or the right to build in the receiving area should not be so restrictive so as to

force purchase of development rights for any type of development. Failure to allow some

use by right in the receiving district might be challenged as a taking.162

The Miami-Dade Board of County Commissioners adopted the East Everglades

Ordinance in 1981 that declares the Everglades an area of critical significance and

implements land use regulations that allow the transfer of development rights. The

programs is referred to as a severable use rights (SUR) program, because the right to

develop is “severed” from the sending property and transferred to a receiving property

more appropriate for development. The Miami-Dade County SUR program identifies

156 AMERICAN FARMLAND TRUST , supra note 30, at 128.

157 PRUETZ, supra note 129, at 128.

158 DANIELS, supra note 38, at 226.

159 PRUETZ, supra note 129, at 128.

160 Id.

161 DANIELS, supra note 38, at 226.

162 SALKIN, supra note 126, at § 56.04[3]; for further discussion of legal issues see Juergensmeyer, supra

note 27, and Miller, supra note 144.

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sending parcels within the East Everglades area and receiving parcels within the UDB.

The ratio for SURs varies from one SUR per five acres to one SUR per 40 acres.

The East Everglades Ordinance imposes strict environmental regulations within

the sending areas that include road standards and excavation limitations. As a result of

the environmental limitations and the density restrictions, landowners find it very

difficult and expensive to build in the East Everglades, providing incentives for them to

sell their development rights.

The receiving site may use the SURs to increase density, lot area, frontage, and

other development requirements on residential and commercial receiving sites in the

unincorporated parts of Miami-Dade County that are designated for urban development.

Sending zones are also eligible for a 10 percent reduction in the minimum lot size, a one

third reduction in the required front setback and an 18 percent increase in density.

Additional commercial floor area is allowed in commercial and office park zones.

Although initially of limited success, the success of the SUR program has

increased since 1995 because the Comprehensive Development Master Plan provides for

the use of SURs; the transfer ratios are high in certain areas; the ordinance has eighteen

different zones that can receive SURs; the administrative process is predictable and

uncomplicated; and the local government is supportive of the program. The Miami-Dade

County program is also successful because there is a substantial demand for additional

development in the area. Developers have found it cheaper to buy SURs than to buy

land. By the end of 1994, 213 SURs had been transferred to receiving sites.163

5. Florida Rural and Family Lands Protection Act

Passed by the Florida Legislature in 2001, the Rural and Family Lands Protection

Act (Act) allows the Department of Agriculture and Consumer Service (DACS) to protect

ranch and timber land by offering four options to willing land owners. DACS may:

· Purchase traditional permanent conservation easements;

· Purchase less restrictive rural land protection easements;

· Purchase agricultural easements, which are 30 year restrictions on development

and subdivision with an option for the government to buy the land; or

· Pay farmers to improve wildlife habitat and water resources on their land under a

permanent conservation easement.

While conservation easements are a familiar tool in Florida (see discussion above)

the Act is innovative in that it institutes options for varying degrees of restriction and

time parameters. It adds flexibility for both landowners and easement holders that was

not previously available. The Act is supported by the agricultural industry as a means to

keep family farms in business and realize value for their property while protecting the

property from subdivision and development.

While the Act passed in 2001, no funding has been set aside for the program. In

December of 2001, the DACS issued a legislative report that described the types of lands

163 PRUETZ, supra note 129, at 85.

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that would receive priority under the program. However, the 2002 and 2003 Legislatures

failed to allocate funds to the program. DACS had requested approximately $10 million

to fund the project. If future legislatures fund the program, this Act will significantly

impact local rural programs around the state, including Miami-Dade County. Funding

from the state- level can radically augment local efforts to preserve open space and rural

lands.164

D. Taxation Programs

The disparity between the market value of agricultural land for agriculture and for

other uses increases the pressure on farmers to sell their farms.165 To reduce the

temptation or need to sell many states have enacted legislation giving real property tax

deferments, preferences, or exemptions to the owners of agricultural or eligible land.

Besides agriculture, eligible uses might be open space or timber production. Tax

programs can be effective when used in tandem with other mechanisms. Though tax

incentives do reduce the tax pressure, they do not always reduce the development

pressure, as the capital gains for land development may still outweigh the property tax

incentive in some markets.166

The purpose of agricultural tax programs is to help farmers stay in business by

reducing their real property taxes; to treat farmers fairly by taxing farmland based on its

value for agriculture instead of its value for development; and to protect farmland by

easing the financial pressures that force some farmers to sell their land.167 Tax programs

are beneficial because they correct inequities in the tax system created by development

pressures and they help farmers stay in business. Tax programs, unfortunately, cannot

ensure long term protection of farmland, and are criticized when they inadvertently

provide a subsidy to real estate speculators who keep their land in agriculture pending

development.168

1. Differential Assessment

Differential tax programs provide incentives for landowners to keep their land in

agriculture by assessing agricultural lands at its current or farm value rather than its fair

market value.169 Agricultural value represents what farmers would pay to buy land in

light of the net farm income they can expect to receive from it. Full market value

represents what a willing buyer would pay for the land.170 Every state except for

Michigan has a differential assessment program. There are three kinds of differential

assessment programs: preferential assessment, deferred taxation, and restrictive

agreements.

Preferential assessment is the least restrictive of the three types because it does

not impose penalties for converting land to non-eligible uses. The agricultural value is

164 See Lancaster County, Pennsylvania, Task 2(c) Report.

165 Id. at 285.

166 Id.

167 DANIELS, supra note 38, at 147.

168 Id. at 151.

169 FREILICH, supra note 29, at 285.

170 DANIELS, supra note 38, at 147.

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multiplied by the local tax rate to determine the amount of real value tax due each year.

Farm buildings are generally taxed at their fair market value. These programs base

farmer’s tax bills on the agricultural value instead of the fair value as long as the lands

remain in agricultural use.171

The principle behind a deferred taxation program is that the tax on the market

value of the property is deferred until the property is developed. Deferred taxation

programs use the same process as preferential assessment programs to calculate property

taxes. The difference is that a tax is imposed on the landowner when the land is

converted to non-eligible uses or sold for development. Some states impose “rollback”

penalties that are calculated based on the sum of the tax benefits received, while other

states just require the landowner to pay a conversion tax. 172 Most states require

landowners to renew their application for tax deferment each year.

The taxation programs are designed to target commercial agricultural land rather

than small farms used for recreation or land that is vacant pending development. To

achieve this goal landowners may be required to sign restrictive agreements (California)

or restrictive covenants (Georgia, Hawaii, New York and Pennsylvania). The restrictive

agreements must be signed as a condition precedent to the reassessment of the land for

agricultural purposes.173 In Minnesota, this goal is achieved by having fairly restrictive

eligibility criteria whereby lots must be at least 10 acres, and meet an ownership and

production test. For the ownership test, the land must be the owner’s homestead or that

of a surviving spouse, child or sibling; the land must have been in possession of one of

the previously mentioned parties for seven years; or the land must be the homestead of a

shareholder in a family farm corporation. To be considered an eligible use the land must

be devoted to production of farm products for sale that provide at least 1/3 of the family’s

income, or yield at least $300 plus $10 per tillable acre in total income, including rent.174

The Florida Constitution provides for a differential assessment for agricultural

lands.175 Whether or not land is considered agricultural land for tax assessment purposes

depends on the length of time the land has been utilized as agricultural land; the purchase

price paid; the size, as it relates to specific agricultural use; whether effort has been made

to care sufficiently and adequately for the land in accordance with accepted commercial

agricultural practices, including, without limitation, fertilizing, liming, tilling, mowing,

reforesting, and other accepted agricultural practices; whether such land is under lease

and, if so, the effective length, terms, and conditions of the lease; and such other factors

as may from time to time become applicable.176 After land is qualified as agricultural

land, it is eligible for differential tax assessment.

2. Circuit Breaker Tax Relief Credits

Circuit breaker programs allow for farmers to take tax credits for part of their

local property tax bill. The cost of the tax credit is distributed among all the taxpayers in

171 Id. at 153.

172 Id. at 154.

173 FREILICH, supra note 29, at 286.

174 DANIELS, supra note 38, at 154.

175 FLA. CONST. ART 7 §4.

176 FLA. STAT. CH. 193.461 (2002).

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the state. A circuit breaker program depends on involvement at the state level. Only

Michigan, Wisconsin, New York and Iowa have instituted circuit breaker programs.

The New York program, adopted in 1996, provides farmers who earn at least 2/3

of their total household income from farming with relief from local school taxes levied on

agricultural land and buildings. Farmers receive a full credit for up to 250 acres of

farmland and a fifty percent credit for more than 250 acres. The amount of credit also

depends on a family’s income.

The other state programs operate similarly but also can require the farmer to sign

a restrictive agreement where the farmer promises not to build any non- farm structure for

ten years. In return, farmers are protected against taxes levied by local utilities and

receive credits against their state income taxes.177

3. Real Estate Transfer Taxes

Real estate transfer taxes are taxes on various property transactions such as the

transfer of property deeds and the transfer of a controlling ownership interest in entities

which own real property. 178 Many states, including Florida, charge the tax when a deed

is recorded. State statutes generally spell out the conditions of the tax and for what

purposes the revenue may be used.

Real estate transfer taxes are frequently used for farmland preservation.

Maryland is the leading state using this type of tax through a ½ percent tax on the value

of all real estate transfers that is divided between parkland acquisition and farmland

protection. 179

Florida’s real estate transfer tax, called the documentary stamp tax, is codified in

Chapter 201 of the Florida Statutes. The tax is primarily levied by the state and the

revenue is used for numerous purposes including the purchase of conservation lands

through Florida Forever and the Land Acquisition Trust Fund.180 Counties may assess

documentary stamp taxes in limited situations and only for the purpose of funding the

Housing Assistance Trust Fund.181 Miami- Dade County is the only Florida county that

has imposed a documentary stamp tax. 182

177 DANIELS, supra note 38, at 155-156.

178 PETER M. FASS; MICHAEL E. SHAFF; DONALD B. ZIEF, REAL ESTATE INVESTMENT TRUSTS HANDBOOK

§ 5:71 (2003).

179 AMERICAN FARMLAND TRUST, supra note 30, at 101; see also discussion of Montgomery County in

Task 2(c).

180 FLA. STAT. CH. 201.15.

181 FLA. STAT. CH. 201.031.

182 MIAMI-DADE COUNTY ORDINANCES 29-7.

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E. Funding Programs

1. Impact Fees

Impact fees are mandatory payments paid by developers or builders in return for

development approval. They are calculated to be the proportionate share of the capital

cost (e.g. roads, schools, sewer lines, or gutters) created by a new development.183 The

charges are generally levied by local governments but are not taxes because impact fees

constitute a single payment, unlike periodic payments of taxes. The costs of developing

infrastructure for a new development are charged at the time of development, reducing

the need of the city or county to rely on bonds,184 and the community is not forced to pay

the high costs of development on the urban fringe or in other areas without existing

infrastructure. Impact fees exist in some form or another in every state in the nation. 185

The power to charge impact fees is derived from local government’s police

powers. While some states enact enabling legislation for impact fees, others, such as

Florida, simply delegate the power to local governments through home rule power.

While local governments have limited powers to impose taxes, they have broad powers to

regulate in order to protect the health, safety and welfare of the community. Courts have

upheld the legality of impact fees if such fees meet the rationale nexus test, which ensures

a rational relationship between the demands of new development and assessments against

it.186 There are two prongs to the rational nexus test. First there must be a need for an

additional public facility (i.e. schools, public safety, sewers) created by the new

development and the fee must not exceed the cost of providing the facility. Second, the

property charged the fee must derive a roughly proportional benefit from the new

facility.187 Impact fees that do not meet this test may be considered takings, entitling the

property owner to monetary damages.

Impact fee programs must be carefully designed so the fees are reasonable, and

fairly and accurately reflect a new development’s fair share of the necessary facility. 188

Local governments often use careful economic analysis and planning to determine impact

fees. “The most widely implemented and judicially upheld impact fees are based on data

which indicate desired level-of-service standards for a particular facility and calculate the

cost of maintaining those standards in light of the increased demands created by new

development.”189 While impact fees have not traditionally been used as a direct tool to

protect agricultural land, they have been used as part of an overall growth management

policy.

183 Frank, James E. & Paul B. Downing, Patterns of Impact Fee Use, in DEVELOPMENT IMPACT FEES 3

(Arthur C. Nelson ed. 1988).

184 Id. at 4.

185 James C. Nicholas, Julian C. Juergensmeyer & Ellen Margrethe Basse, Perspectives Concerning the Use

of Environmental Mitigation Fees as Incentives in Environmental Protection (Part I), 7 ENVTL. LIABILITY

25, 28 (1999).

186 See Id. at 30; Jordan v Village of Menomonee Falls, 137 N.W. 2d 442 (Wis. 1965).

187 James C. Nicholas, supra note 185, at 37; see also Sarasota County v. Sarasota Church of Christ, Inc.,

667 So.2d 180, 183 (Fla.1995).

188 Nicholas, supra note 185, at 30-1.

189 Id. at 31.

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2. Environmental Mitigation Fees

A new type of impact fee is being proposed by environmental advocates called

environmental mitigation fees, one purpose of which may be agricultural preservation.

Environmental mitigation fees are a hybrid between impact fees and market based

environmental mitigation models. “The goal of environmental mitigation fees is to

harness market forces to make environmental protection profitable.”190

Traditionally, environmental pollution fees have been assessed on a case-by-case

basis.191 Each individual development or polluting facility has been required to mitigate

its own impact on its own site, or mitigate its impact through some regulatory means.192

The problem with this approach is that it may not meet comprehensive environmental

goals for the community because it is not based on a community wide plan.

An environmental mitigation fee requires long-range planning for environmental

goals. Agriculture and environmentally sensitive lands, critical habitat, endangered

species and other critical resources are identified early on. Then, the comprehensive plan

guides the assessment of impact of any development. “Government regulators would

determine the units of environmental impact associated with a new or existing project and

multiply the number of units by a price per unit.”193 A developer would be charged based

on the formula and may choose (1) to pay and proceed with the project; (2) to reduce the

adverse impact and pay a reduced fee; or (3) to pay another firm to mitigate adverse

environmental impact elsewhere.194 The money generated by the program could go into

preserving agricultural land through the purchase of development rights, a TDR program,

or other method discussed in this paper.

Although not a fee-based arrangement, in Miami-Dade, environmental impacts

are mitigated through regulatory mechanisms. Section 24-58 of the County Code

requires a permit for any development that alters County canal rights-of-way, mangrove

trees, tidal waters, submerged bay bottoms, wetlands, natural surface flows, or critical

groundwater sources. The environmental mitigation fee would be collected and used in

the protection of these same environmental resources.

3. Federal Programs

The United States Department of Agriculture (USDA) has a number of programs

to assist state and local governments and individual landowners with conservation. The

Food Security Act of 1985 created the Farmland Protection Program (FPP) which

provides funds to help purchase development rights to keep productive farmland in

agricultural uses.195 This program was recently reauthorized and modified by the Farm

190 James C. Nicholas, Julian C. Juergensmeyer & Ellen Margrethe Basse, Perspectives Concerning the Use

of Environmental Mitigation Fees as Incentives in Environmental Protection (Part II), 7 ENVTL. LIABILITY

69, 71 (1999).

191 Id.

192 Id.

193 Id.

194 The third option might be similar to off site mitigation programs such as pollution trading and wetlands

mitigation programs. For more information see James C. Nicholas, supra note 185.

195 Pub. L. No. 99-198, 99 Stat. 354 (1985).

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Security and Rural Investment Act of 2002.196 The general purpose of the program is "to

establish and carry out a farmland protection program under which the Secretary shall

purchase conservation easements or other interests in eligible land… for the purpose of

protecting topsoil by limiting nonagricultural uses of the land."197

The program is administered through the Natural Resources Conservation Service

(NRCS), a division of the USDA. The NRCS provides technical and financial assistance

to state, tribal and local governments and non-governmental organizations that already

have farmland protection programs. Through the benefit of the FPP these governments

and organizations acquire easements and interests in land, while landowners agree to

develop and carry out a conservation plan on the land. A total of $30 million was

available in 2001 for the program.

States may cooperate with the federal government to devise creative funding

techniques for agricultural preservation. Martin County, Florida recently agreed to pay

for the speedy installation of water lines for a Superfund project that will bring clean

water to its residents. While a state’s portion of Superfund programs is usually only 10

percent, in exchange for Florida's payment of the full cost of the project, the federal

agency has agreed to give Florida a credit that can be used to offset the state's share of

future cleanups.198 A similar program could be used for agricultural preservation or the

federal government might opt to give credit for farming programs as well as for clean up

programs.

F. Regulatory Techniques

1. Growth Tiers

Timing and sequencing deve lopment to coincide with the provision of public

facilities was first implemented in an innovative plan in Ramapo, New York and was

upheld by the courts in the landmark decision Golden v. Planning Board of Town of

Ramapo.199 The basic idea is that all residential development must proceed in accordance

with the provision of adequate municipal facilities as established by a long-term

comprehensive and capital improvement program.200 The importance of the Ramapo

plan is the recognition of the fundamental constitutional principle that development on

the urban fringe can be controlled by linking the development with the planned extension

of capital improvements over a reasonable time.

A “tier” system utilizes the Ramapo principle by providing for the delineation of

functional areas within the region for the identification of goals and objectives and the

implementation of growth management techniques.201 Generally five tiers are created.

Tier I consists of the downtown area or urban core. Tier II consists of existing residential

areas within the urban area and older suburban areas. Tier III consists of the actively

196 Pub. L. No. 107-171, §2503, 116 Stat. 134, 267 (2002)

197 Id. at 268.

198 John Cushman Jr., Superfund Makes a Rare Deal with Florida, N.Y. TIMES, July 31, 2002, available at

http://www.nytimes.com/2002/07/31/politics/31SUPE.html. (August 2, 2002).

199 Golden v. Planning Board of Town of Ramapo, 334 N.Y.S. 2d 138 (N.Y. App. 1972).

200 Freilich, supra note 5, at 34.

201 Id. at 35.

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development area. Tier IV is the rural and agricultural land that is inappropriate or

premature for development. Tier V incorporates environmental and agricultural zones

that warrant preservation or protection. 202 The number of tiers varies according to the

current and desired land use pattern within the urban area, but will be similar to the

system described above.

2. Concurrency Programs

Concurrency programs tie development approvals to level of service (LOS)

standards. LOS standards measure the ratio of public facility capacity to the need for the

facility. Such a program takes into account all demand for the facilities, including

existing demand as well as the additional population added by new development

proposals. An adopted LOS standard reflects a policy decision concerning the

appropriate equilibrium between population and public facilities that may be applied to

new development in the standard setting and review process, and to the public capital

budgeting process. LOS standards conveniently provide a benchmark for monitoring the

growth management system.203

Florida was the first state to introduce “concurrency” requirements; the Florida

Statutes specifically provide that, “[P]ublic facilities and services needed to support

development shall be concurrent with the impacts of such development.”204 The

requirement is part of Florida’s Growth Management Act of 1985 that was enacted to

discourage urban sprawl, improve existing infrastructure to support infill and

redevelopment, and to discourage urban development of rural lands.205

Concurrency programs do not concentrate on one particular sector of a city or

county; they look at a community comprehensively to plan for the entire area. The result

is that growth occurs at a rate that is economically beneficial to the community and in a

manner that retains land values. The specific techniques discussed above should be

implemented within the framework of the comprehensive plan.

Miami-Dade County has a Service Concurrency Management Program. No

development order shall be issued where LOS standards for all public facilities will not

meet or exceed LOS standards or where such an order would result in a reduction of

services, except in certain circumstances, such as when the development is located in a

designated urban infill area.

202 Id.

203 S. Mark White, Adequate Public Facilities Ordinances and Transportation Management 8. PAS Report

465 (1996).

204 West’s Fla. Sta. Ann. Section 163.3177 (10)(h).

205 See generally West’s Fla. Sta. Ann. Section 163.

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3. Urban Service Boundaries

An urban service boundary (USB)206 is a relatively simple technique for

channeling growth that involves designating an urban services area and a rural service

area. Planning studies designate the urban services areas, which are the most suitable to

the extension of municipal services such as streets, sewers, and water, and rural service

areas where development is restricted.207 The municipality commits to providing urban

services within the urban service area before going beyond it.208 One of the most

important attributes of a USB is that it makes the development pattern predictable for

landowners and developers.209

There are generally four goals for a USB: (1) to make the most efficient use of

public tax money for infrastructure funding; (2) preservation of agricultural and

environmentally sensitive lands; (3) efficient provision of municipal services; and (4)

promotion of compact urban development.210 The USB also preserves agricultural land

values within the community.

The most challenging issue surrounding a USB is how and under what

circumstances the boundary should be moved.211 The location of a USB significantly

impacts how a community develops, and in the agricultural context, may determine what

agricultural land is given over to development and what land is preserved for farming.

Therefore, adjustments to a USB should only take place after deliberate planning

considerations, that take into account both urban and rural interests.212 An effective

boundary adjustment process should be “firm enough to provide predictability for longrange

planning, yet sufficiently flexible to respond to changed conditions.”213 Some

states, such as Oregon, set out guidelines for adjusting boundaries. These guidelines

include compliance with a comprehensive plan, and the analysis of socio-economic

impacts on the community and the existence of intergovernmental agreements.214

Intergovernmental coordination is required to successfully implement a USB

program because most urban cores are associated with a municipality separate from the

unincorporated area of the county. 215 Intergovernmental agreements should define the

role of each governmental entity involved and describe the process for boundary

adjustments.

Miami-Dade County’s Urban Development Boundary (UDB) is a USB. Details

of the Miami-Dade County UDB are provided above in Section II.

206 A USB is different from an urban growth boundary that identifies an urban core and designates certain

uses appropriate. The focus is less on urban services than on uses such as siting of future development,

protection of natural lands and resources, and compact urban form. See Smith, supra note 47 at 19.

207 CALLIES, supra note 78, at 642.

208 V. Gail Easley, Staying Inside the Lines 10 PAS Report 440 (1990).

209 Smith, supra note 47, at 19.

210 See Wash. St. Ann. § 36.70A. 110 (2003)

211 Smith, supra note 47, at 20.

212 Id. at 20.

213 Easley, supra note 208, at 10.

214 Id. at 4.

215 Smith, supra note 47, at 21.

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IV. ECONOMICS AND THE LAW

A. Economic Value of Land

Preventing sprawl may be the most effective method of preserving the economic

value of land in Miami-Dade County. A 1995 Bank of America report stated, “Growth

has helped fuel … an unparalleled economic and population boom and has enabled

millions … to realize the enduring dream of home ownership … but sprawl has created

enormous costs… Ironically, unchecked sprawl has shifted from an engine of … growth

to a force that now threatens to inhibit growth and degrade the quality of our life.”

Indeed, the public infrastructure gap is nearing $4 trillion. Such high costs for

infrastructure impede development of community services and inhibit the preservation of

open space and agricultural lands. If urban growth consumes agricultural land, and

government money is spent building infrastructure, then community services and existing

infrastructure suffer. One conservative critic notes that more flexible zoning codes

“would allow for more innovative development designs that accomplish conservation

goals and satisfy consumer demand for housing alternatives. Ensuring that development

covers its infrastructure expenses will allow the marketplace to operate freely and

efficiently.”216

Preserving the economic value of land in Miami-Dade County can be

accomplished by concentrating on four goals:

1. Economic development through the preservation of agriculture;

2. Clustering of new development outside the urban area to reduce sprawl

and reduce infrastructure costs;

3. Maintain the character outside of the urban area; and

4. Develop strategies that are legally defensible.

B. Legal Framework

The following is intended to give a very general overview of the legal issues that

arise when local governments in Florida undertake planning and plan implementation.

Further legal analyses should be undertaken to address any specific program or ordinance

considered by the County for adoption.

The authority of local government agencies to adopt land use and zoning

regulations is derived from a state’s police power authority. Generally, comprehensive

growth management programs include police power regulations such as a zoning

ordinance incorporating density standards. Governments have the authority to regulate

the activity or use of property in order to protect or to prevent harm to the public health,

safety and welfare.217 Though there are limitations on a government’s police power, the

216 Samuel R. Staley & Matthew Hisrich, True Smart Growth, The Buckeye Institute Newsletter (May

2002), available at http://www.rppi.org/opeds/ohiosmartgrowth052102.pdf (August 2, 2002).

217 See Keystone Bituminous Coal Assoc. v. DeBenedictis, 107 S.Ct. 1232 (1987); Euclid v. Ambler Realty

Co., 272 U.S. 365 (1926); and Goldblatt v. Town of Hempstead, 369 U.S. 590 (1962).

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courts have recognized the need for plans to deal with critical issues such as urban

sprawl, declining land values, environmental degradation, a lack of open space, and

agricultural preservation. 218

Nonetheless, there are several types of legal issues that must be considered.

Generally, (1) does the local government have authority or police powers; (2) does the

action advance a legitimate governmental purpose; (3) is the system applied equally to

persons and land without operating in a discriminatory manner; (4) are the governmental

regulations implemented such that there is no "taking" of private property without "just

compensation"; and (5) do the government regulations afford substantive and procedural

due process to persons affected?

The authority of Florida’s local governments to plan is undisputed, and in fact

mandated, by Florida’s Growth Management Act of 1985. The other issues are

considered under three major headings: takings, impact fees/mitigation fees and due

process.

1. Takings

The majority of legal challenges to land use regulations fall under the claim that

the regulations constitute a "taking" of private property without "just compensation". 219

If the purpose is to protect the public welfare, government may limit use of property

through regulation without a finding that a taking has occurred under the Fifth and

Fourteenth Amendments of the U.S. Constitution. 220 However, once a regulation221 has

been deemed to effectuate a taking, monetary compensation may be required to be paid 222

or the regulation voided. If the regulation223 does not involve a physical or title taking,

but is in the nature of amenity protection such as open space preservation, environmental

protection, or agriculture preservation, the standard used is a balancing test to determine

whether the benefit to the public is outweighed by the burden to the land owner. The test

has two prongs: (1) does the regulation substantially advance a legitimate state interest,

and (2) does it deny an owner economically viable use of land.224

218 Robert H. Freilich & Jason M. Divelbiss, The Public Interest is Vindicated, 31 URBAN L. 731, 734

(1999).

219 The following analysis involves a discussion of federal takings jurisprudence, which is applicable in

both federal courts and state courts in Florida.

220 Keystone Bituminous Coal Assoc., supra note 217.

221 Since the seminal case Penn. C. Transp. Co. v. N. Y. C. Landmarks Commn., 438 U.S. 104 (1978), the

United States Supreme Court has recognized three kinds of regulatory takings: physical, title, and

economic. A physical taking is one where a governmental entity invades private property regardless of the

extent of diminution in property value. See Kaiser Aetna v. U. S., 444 U.S. 164 (1979). A title or exaction

taking does not involve land invasion, but results from the government accepting a title dedication or

monetary exaction representing a payment in lieu of dedication. See Nollan v. Ca. Costal Commn, 483 U.S.

825 (1987) and Dolan v. City of Tigard, 512 U.S. 374 (1994). An economic taking is one where a

regulation does not substantially advance legitimate state interest and denies an owner of economically

viable use of his land. See Agins v. City of Tiburon, 447 U.S. 255 (1980).

222 First English Evangelical Church v. County of L. A., 107 S.Ct. 2378 (1987).

223 Nollan, supra note 221.

224 See, e.g. Agins supra note 221; Haw. Hous. Auth. v. Midkiff, 467 U.S. 229 (1984); and Lucas v. S. C.

Costal Council, 505 U.S. 1003 (1992).

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Under the first prong, the court will not construe the governmental action to be a

taking as long as the governmental entity has reasonably concluded that “the health,

safety, morals, or general welfare would be promoted by prohibiting a particular

contemplated use of land.”225 The courts also require that the regulation is reasonably

calculated to meet the evil without exceeding the public necessity or substantially

affecting uses that do not “partake of the offensive character of those which create the

problem sought to be ameliorated.”226 In short, the government must craft regulations in a

manner that is rationally- related to the legitimate purpose it seeks to advance.

Under the second prong, a court must determine whether the property maintains

any permanent beneficial value when viewed as a whole.227 Both federal and state courts

have uniformly held that all substantial use of property must be lost before an economic

taking occurs. Economic takings must be viewed in their entirety, and therefore a

diminution in value of even 99 percent has not been viewed as a taking.228

TDR programs have been particularly susceptible to takings claims, but if the

TDR system is designed appropriately it will be upheld. The key to a successful program

is effectively protecting the sending area's resources while offering the property owner

fair and reasonable compensation. Florida courts have upheld TDR programs in City of

Hollywood v. Hollywood, Inc229 and Glisson v. Alachua County.230In the Hollywood

case, the court upheld a city zoning ordinance that restricted beachfront lots to singlefamily

dwellings and granted the owner TDRs that could be applied to adjacent lots to

increase permissible density. The purpose of the ordinance was to preserve the

beachfront property, and the court dramatically noted, “Before us is the last unspoiled

beach area on the Gold Coast, a veritable Shangri-La in an otherwise endless Himalayan

mountain range of cement to the south.”231 In Glisson, the court upheld a TDR program

designed to protect threatened wetlands. In both cases, the court found that protecting

open space and environmentally sensitive areas was a legitimate state interest.

2. Impact Fees/ Mitigation Fees

Although there is no specific case law on mitigation fees in Florida, a review of

the impact fees jurisprudence is relevant because any mitigation fee legal analysis should

follow the same arguments. In 1994, the U.S. Supreme Court decided the important case

of Dolan v. City of Tigard232 holding that not only must exactions have the required

nexus to a development’s impacts (a matter settled in Nollan v. California Coastal

Commission,),233 but also that the degree of the exaction must be “roughly proportional to

225 Penn C. Transp. Co., supra note 221, at 125.

226 Kirsch Holding Co. v. Borough of Manasquan, 59 N.J. 241, 281 A.2d 513, 518 (1971).

227 See, e.g. Concrete Pipe and Products, Inc. v. Constr. Laborers Pension Trust, 508 U.S. 602, 643-44

(1993); Pennel v. City of San Jose, 485 U.S. 1 (1988); Hodel v. Irving, 481 U.S. 704 (1987).

228 Concrete Pipe and Products, supra note 227; see also City of Monterey v. Del Monte Dunes, 119 S.Ct.

1624 (1999).

229 432 So. 2d 1332 (Fla. Dist. Ct. App. 1983), review denied, 441 So. 2d 632 (Fla. 1983).

230 588 So. 2d 1030 (Fla. Dist. Ct. App. 1990), review denied, 570 So. 2d 1304 (Fla. 1990).

231 Hollywood, supra note 229, at 1337-388.

232 Dolan, supra note 221.

233 Nollan, supra note 221.

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the projected impact of the proposed development.”234 Local governments must

demonstrate that exactions imposed as a condition of development are not only related in

nature, but also in extent, to the impact of the development paying the fee.

The Florida Supreme Court has upheld local government’s authority to impose

impact fees based on general home rule and police power theories. The Growth

Management Act specifically encourages the use of impact fees,235 and Florida courts

have adopted the rational nexus test as the appropriate standard by which to measure their

validity. 236 However, just as other land development regulations can only be exercised

within the bounds of substantive due process, so too are impact fee impositions similarly

bound. The Florida Supreme Court has adopted237 and reaffirmed238 the dual rational

standard as the appropriate measure of whether a local government has exceeded its

constitutional authority in the imposition of impact fees. Based on this case law, it is

likely that mitigation fees would be upheld in Miami-Dade County.

3. Due Process

Many land use claims are based on the due process clause of the Fourteenth

Amendment. Procedural due process is not discussed here as individuals cannot bring

these suits against a government for a legislative action. Substantive due process imposes

a requirement that the land use regulations must promote a legitimate public end in a

rationale manner.239 Legitimate state interests are often described in zoning laws in terms

of the protection or furtherance of the public health, safety, morals, or general welfare. A

landowner may assert that the regulation is arbitrary and capricious, bearing no

substantial relation to the public health, safety, morals, or general welfare, and is

therefore an invalid exercise of the police power (an “arbitrary and capricious due

process” or “substantive due process” claim).240 This standard is a heavy burden for a

landowner to overcome.241

V. MIAMI-DADE COUNTY – VALUE PRESERVATION PRINCIPLE

The following analysis presents a guiding principle for analyzing how the County

might develop a program that will retain the value of agricultural land while

simultaneously protecting open space and rural areas for future generations. Although

the final recommendation (Task 2(d)) will be presented in light of the development

scenarios outlined in Task 1(f), the Team, based on the extensive input of the Citizens’

Advisory Committee, has determined that the final recommendation – the “preferred

development scenario – should set forth a means of protects open space in perpetuity in a

234 Dolan, supra note 221, at 388.

235 See FLA. STAT. ch. 163.3202(3) (2001).

236 Home Builders & Contract Assocn. of Palm Beach County, Inc. v. Board of County Commissioners,

446 So.2d 140 (Fla. 4th DCA 1983).

237 Contractors & Builders Assocn., Inc. v. City of Dunedin, 329 So.2d 314 (1976).

238 St. Johns County v. Northeast Florida Builders Assocn., Inc. 583, So.2d 635 (Fla. 1991)

239 CALLIES, supra note 78, at 349.

240 Eide v. Sarasota County, 908 F.2d 716, 722 (Fla. 1990); Euclid supra note 217, at 395.

241 Restigouche v. Jupiter, 59 F.3d 1208, 1214 (11th Cir. 1995) (applying same rational relationship test as

in equal protection cases).

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manner that also protects the land investments made by property owners in the Study

Area. In order to meet the complex, and sometimes competing, goals of open space

preservation, a comprehensive program that includes any number of the agricultural

preservation techniques discussed in this paper - and more thoroughly in the Task 2(c)

report - may be employed. However, the Team recommends that the following principle

guide the ultimate recommendation:

Is there a regulatory balance that would provide a landowner a return on

his or her investment equal to or in excess of the reasonable return under

a suburban development alternative, while at the same time preserving

important open space and rural lands?

VI. CONCLUSION

This Report is intended to inform the ongoing analysis being conducted by

the Citizens’ Advisory Committee and the various consultant Team members.

The background concepts set forth here will be refined in forthcoming reports and

analysis. Specifically, Task 2(c), “Analysis of Rural Land Uses,” describes how

five (5) communities from around the country have employed value-preservation

techniques – relying heavily on the concept of PDRs – to protect their threatened

agricultural economies and rural open space. In each case, these communities

have sought to protect the resource most critical to a viable agricultural economy

– the land. Furthermore, consistent with the guiding principle set forth in the

section above, each of these communities has done so by adopting funding

programs that ensure that the community at large, which benefits from the

preservation of this discrete area of the jurisdiction, shares in the burden of

agricultural preservation.

Back to Top

Abstract: Restoring the Urban Forest Ecosystem1

Mary L. Duryea, Eliana Kämpf Binelli, and Lawrence V. Korhnak, Editors2

1. This document is the Abstract, Table of Contents, and Acknowledgments for SW-140, Restoring the Urban Forest Ecosystem, a CD-ROM (M.L. Duryea,

E. Kämpf Binelli, and L.V. Korhnak, Eds.) produced by the School of Forest Resources and Conservation, Florida Cooperative Extension Service,

Institute of Food and Agricultural Sciences, University of Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Mary L. Duryea, Professor and Extension Forester, Eliana Kämpf Binelli, Extension Forester, and Lawrence V. Korhnak, Senior Biological Scientist,

School of Forest Resources and Conservation, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, PO Box

110410, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Restoring the Urban Forest

Ecosystem

The urban forest ecosystem can provide many

ecological services and benefits to cities and

communities including energy conservation,

contributing to global biodiversity, and maintaining

hydrologic and nutrient cycles. Yet in many

instances these benefits are not realized due to poor

health and management of the urban forest. Many

opportunities for restoration -- reestablishing the

structure and function of the urban forest ecosystem

-- exist. The goal of restoration is to return the urban

forest to a form which is more ecologically

sustainable. A restored urban forest will contribute

positively to the community instead of being a drain

on its resources. Many of our parks are composed of

trees and grass requiring intensive maintenance

inputs such as fertilizing, irrigating, mowing and

raking. With restoration these parks could take

advantage of natural processes such as nutrient and

water cycling, thereby saving money, energy and

resources for the community. Connecting these

restored parks to other ecosystems such as

waterways can also contribute to biodiversity and

wildlife conservation. Restoration sites can range

from backyards to neighborhoods to parks to whole

waterways and metropolitan areas. The United States

hosts an abundance of successful and innovative

urban forest restoration projects which illustrate the

potential for creativity, diversity and the ability to

tailor projects to local needs and opportunities. This

CD-ROM explains basic ecological principles for the

urban forest's water, soil, plant and animal

communities. It discusses problems common in the

urban forest such as aquatic eutrophication, soil

aeration, invasive plants and loss of biodiversity.

Solutions, strategies, examples, and additional

resources are presented to help make urban forest

restoration projects successful. Its goal is to inspire

the restoration of urban forest ecosystems which will,

in turn, restore and conserve our planet for future

generations.

Contents

Chapter 1: Restoring the Urban Forest

Ecosystem - An Introduction - Mary L. Duryea

Chapter 2: Basic Ecological Principles for

Restoration - Mary L. Duryea, Eliana Kämpf

Binelli, and Henry L. Gholz

Abstract: Restoring the Urban Forest Ecosystem 2

Chapter 3: Biodiversity and the Restoration of the

Urban Forest Ecosystem - Eliana Kämpf Binelli

Chapter 4: Plant Succession and Disturbances

in the Urban Forest Ecosystem- Eliana Kämpf

Binelli, Henry L. Gholz, and Mary L. Duryea

Chapter 5: Developing a Restoration Plan

That Works - William G. Hubbard

Chapter 6: Restoring the Hydrological Cycle

in the Urban Forest Ecosystem - Lawrence V.

Korhnak

Chapter 7: Site Assessment and Soil

Improvement - Kim D. Coder

Chapter 8: Enriching and Managing Urban

Forests for Wildlife - Joseph M. Schaefer

Chapter 9: Invasive Plants and the

Restoration of the Urban Forest Ecosystem -

Hallie Dozier

Chapter 10: Glossary of Terms for Restoring

the Urban Forest Ecosystem - Eliana Kämpf

Binelli, Mary L. Duryea, and Lawrence V. Korhnak

Acknowledgments

We are grateful for funding from the USDA

Forest Service, Cooperative Forestry through the

National Urban Community Forestry Advisory

Council's grants program. Special thanks to Suzanne

del Villar who patiently waited for all our reports.

We are also most grateful to Ed Macie, USDA Forest

Service, Region 8, Atlanta, who in addition to

supporting this CD-ROM has enthusiastically guided

and sponsored the Urban Forestry Institute for over

ten years.

At the University of Florida, we would like to

thank Wayne Smith for his continued encouragement

and support for this project. Also, many long hours

were spent by Howard Beck and Petraq Papajorgji of

IFAS Information Technologies they planned,

designed and successfully created this CD-ROM and

its printable version. They were assisted by Anna

Beck, Joe Bess and Rayna Elkins. Thank you all so

much.

We found many beautiful photos to describe

projects around the U.S. Everyone is credited with

each photo but we would like to extend our thanks to

all you photographers for your generosity in sharing

these beautiful scenes with us.

And finally, the authors also extend their sincere

gratitude to the many people around the U.S. who

shared information with us about their restoration

programs: Don Alam, Artesia, NM; Laurie Ames,

City of Seattle Dept. of Neighborhoods; Rob Buffler,

Greening the Great River Park, St. Paul, MN;

Charley Davis, Portland Parks and Recreation, OR;

Meridith Cornett, Minnesota Department of Natural

Resources; Sandy Diedrich, Forest Park Ivy Removal

Project, Portland, OR; Ray Emanuel, Drew Gardens,

NY, NY; Alice Ewen, American Forests,

Washington, DC; Steve Graham, City of Tampa

Parks Department, Tampa, FL; Steve Gubitti, Bill

Baggs Park Restoration, Department of

Environmental Protection, Tallahassee, FL; Paula

Hewitt, Open Road, NY, NY; Judy Okay, Difficult

Run Watershed Project, Virginia Department of

Forestry; Kit ONeill, Ravenna Creek Alliance,

Seattle, WA; John Rieger, Carmel Valley Restoration

and Enhancement Project, CA; Linda Robinson,

Naturescaping for Clean Rivers, Portland, OR; Joe

Schaefer, Schoolyard Ecosystems for Northeast

Florida, Gainesville, FL; Beth Stout, National

Wildlife Federation, Portland, OR; David M.

Wachtel, Chicago Wilderness; David J. Welsch,

USDA Forest Service, Northeastern Division,

Radnor, PA; Paul West, Seattle Dept. of Parks and

Recreation; and Greg Wolley, Metropolitan

Greenspaces, Metro, Portland, OR.

We dedicate this work to all the hard-working,

dedicated and creative people around the U.S. who

are finding so many ways to restore the beauty and

health to the urban forest ecosystem.

Chapter 1: Restoring the Urban Forest Ecosystem: An

Introduction1

Mary L. Duryea2

1. This is Chapter 1 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Mary L. Duryea, Professor and Extension Forester, School of Resources and Conservation, Cooperative Extension Service, Institute of Food and

Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Urban and community forests are often managed

as individual trees instead of whole forest

ecosystems. Cities inventory and manage these tree

species to meet many important needs such as energy

conservation, beauty, and recreation in the city. Yet,

there are many opportunities for urban forest

restoration to provide additional ecological benefits

such as storm-water management, wildlife

management, and biodiversity. Restoring the urban

forest ecosystem is reestablishing the ecological

health of the urban forest ecosystem. The goal of

restoration is to return the urban forest to a form

which is more ecologically sustainable for the

community; the restored urban forest will contribute

positively to the community instead of being a drain

on its resources. Many of our parks, for example, are

composed of trees and grass requiring intensive

maintenance inputs such as fertilizing, irrigating,

mowing and raking. With restoration these parks

could take advantage of natural processes such as

nutrient and water cycling, thereby saving money,

energy and resources for the community. Connecting

these restored parks to other ecosystems such as

waterways can also contribute to biodiversity and

wildlife management and conservation. The options

for restoration sites include: yards, vacant lots,

shopping centers, schoolyards, parks, industrial

parks, and waterways. The projects can be varied

such as: (1) The simple act of eliminating leaf-raking

in a park to reestablish the natural forest floor and the

natural cycling of nutrients; (2) The establishment of

understory plant species in a schoolyard to promote

wildlife; (3) The eradication of an invasive plant

species which is eliminating much of the understory

biodiversity in a park; (4) The re-design of a parking

lot to decrease stormwater runoff and provide a small

ecological wetland; or (5) The re-creation of a park

with species and ecosystems to be just the way it was

in the 1800s. The United States hosts an abundance

of successful and innovative urban forest restoration

projects. The two key ingredients that make these

projects so successful are the involvement of people

from the community and the formulation of a

restoration plan.

The Urban Forest Ecosystem

To define the urban forest ecosystem we take

the original definition of ecosystem and apply it to

the urban forest.

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 2

The urban forest ecosystem is a collection of

living organic matter (plants, animals, people,

insects, microbes, etc.) and dead organic matter

(lawn clippings, leaf-fall, branches) on a soil (with

all its urban characteristics) through which there is

cycling of chemicals and water and flow of energy.

When we think of the urban forest ecosystem we

can think of the whole city or community as one

ecosystem or we can focus in on a smaller parcel of

land as the urban forest ecosystem. The big picture,

bird's-eye-view is important to identify sites that

might need restoration (Figure 1). For example, we

might see two parks that could be connected with a

greenway to benefit wildlife communities. Or we

might see an area of the city which is void of trees,

an urban heat island, that could be restored with a

tree canopy. Yet, we also need to look at the urban

forest ecosystem as smaller parcels of land such as

neighborhoods, parks, or schoolyards. At this level

we can see specific management alternatives and

specific ecological needs for each of these land units.

Figure 1. When we think of the urban forest ecosystem

we can think of the whole city or community as one

ecosystem or we can focus in on a smaller parcel of land

(a park, schoolyard or industrial park, for example) as the

urban forest ecosystem. Photo by Hans Riekerk

What is "Restoring the Urban Forest

Ecosystem"?

Restoration has traditionally been defined as

reconstructing or repairing something, often a work

of art or ancient building. Ecologists have defined

ecological restoration to be:

• "The return of an ecosystem to a close

approximation of its condition prior to

disturbance." (National Research Council

1992)

• "The intentional alteration of a site to establish

a defined indigenous, historic ecosystem. The

goal of this process is to emulate the structure,

functioning, diversity and dynamics of the

specified ecosystem." (Society of Ecological

Restoration 1992)

• "Ecological restoration is the process of

renewing and maintaining ecosystem health."

(Society of Ecological Restoration 1995)

• "Ecological restoration is the process of

assisting the recovery and management of

ecological integrity. Ecological integrity

includes a critical range of variability in

biodiversity, ecological processes and structures,

regional and historical context, and sustainable

cultural practices. (Society of Ecological

Restoration 1996)

Most of these definitions center around the

recovery, repair or re-establishment of native

ecosystems. Because of the loss of species, the

increase in disturbances and several other factors,

exact restoration may be an impossible feat and

many people wish to call it rehabilitation.

Restoring the Urban Forest Ecosystem is

reestablishing the ecological health of the urban

forest ecosystem.

In urban forest ecosystems we have a very

different situation, and therefore we need to define

restoration differently. The urban forest is a mosaic

or patchwork of highly altered landscapes ranging

from street trees to neighborhoods with landscaping

to shopping centers to waterways to parks to

fragments of remaining native ecosystems. For this

CD-ROM and its series of publications we have

chosen to define restoration as reestablishing the

ecological health of the urban forest ecosystem.

More specifically, restoration means altering a site (a

park, waterway, neighborhood) to a state which is

more ecologically sustainable for the community or

city. Restoration might reestablish ecological

structure, functions, pathways, and/or cycles. A

restored site with its renewed or re-introduced

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 3

ecological attributes will contribute more positively

to the community instead of being a drain on its

resources.

Examples of potential sites and projects for

restoring the urban forest ecosystem include:

• The simple act of eliminating leaf-raking to

reestablish the natural forest floor and the

natural cycling of nutrients.

• The establishment of understory plant species

in a schoolyard to promote wildlife species.

• The eradication of an invasive plant species

which is eliminating much of the understory

biodiversity in a neighborhood.

• The clean-up of a vacant lot or site in a

neighborhood and the establishment of a park.

• The re-design of a parking lot to decrease

stormwater runoff and provide a small

ecological wetland.

• The re-creation of a park with the native

ecosystems that were present 100 years ago.

Potential sites for restoring the urban forest

ecosystem include (Figures 2, 3, and 4):

Figure 2. A vacant or abandoned lot in an industrial area

of town.

Figure 3. A small water-retention pond which could be

restored with wetland species.

Figure 4. A schoolyard.

The Story of two parks

A description of two hypothetical parks offers

insights into the reasons and benefits of restoration.

Wilson Park

• Wilson Park has five baseball fields and four

basketball courts which are under constant use

by the community. (Figure 5).

• A monoculture of 60-year-old pine trees

surrounding the ball fields has swing sets and

picnic tables in its understory (Figure 6). Last

year when bark beetles invested loblolly pines in

nearby parks, plantations and natural areas, park

managers worried that they might lose this pine

forest to the beetle.

• When viewed closely we can see that not only

are there no understory plant species but the park

managers remove every leaf and twig that falls

to the ground (Figure 7).

• In another area of the park, managers work to

maintain a grass understory under several live

oaks (Figure 8). With little light for grass

growth, addition of fertilizers, water and

frequent mowing makes this an intensively

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 4

managed area for the park. Every leaf and

branch must also be removed in these hardwood

and grass forests.

Figure 5. Wilson Park has several baseball fields and four

basketball courts which are under constant use by the

community.

Figure 6. A monoculture of 60-year-old pine trees

surrounding the ball fields has swing sets and picnic tables

in its understory. Last year when bark beetles invested

loblolly pines in nearby parks, plantations, and natural

areas, park managers worried that they might lose this

pine forest to the beetle.

Figure 7. When viewed closely we can see that not only

are there no understory plant species but the park

managers remove every leaf and twig that falls to the

ground.

Figure 8. In another area of the park, managers work to

maintain a grass understory under several live oaks. With

little light, addition of fertilizers, water and frequent mowing

makes this an intensively managed area for the park.

Every leaf and branch must also be removed in these

hardwood forests.

• A bird's-eye-view of another hardwood area

shows very little remaining on the ground

(Figure 9). All leaves have been removed and

the resulting bare soil shows the exposed and

unprotected roots of shrubs and trees (Figure

10).

• This kind of management results in intensive

use of people and energy resources (Figure 11).

Often after the natural leaves and branches are

removed, landscape mulch is brought in to cover

the ground.

• One of the park managers has planted camelias

in one of the bare understories. Because these

are an exotic plant, maintenance of these flower

gardens has included additional fertilization and

installation of an irrigation system (Figure 12).

Andrews Park

• Andrews park has a natural creek running

through it (Figure 13). The creek originates

outside the town, and so the park provides a way

to connect several ecosystems as it meanders

through the park and town.

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 5

Figure 9. A bird's-eye-view of another hardwood area in

the park shows very little remaining on the ground.

Figure 10. All leaves have been removed and the resulting

bare soil shows the exposed and unprotected roots of

shrubs and trees.

Figure 11. This kind of management results in intensive

use of people and energy resources.

Figure 12. One of the park managers has planted

camelias in one of the bare understories. Because these

are an exotic plant, maintenance of these flower gardens

has included additional fertilization and installation of an

irrigation system. Photo by Larry Korhnak

• Several ponds and other wetland areas support

habitat for wildlife in the park (Figure 14).

• A walkway across one of the wetland areas

offers entry and a look at this wetland ecosystem

(Figure 15).

• Fallen leaves and branches maintain a natural

mulch for the park (Figure 16).

• Playground areas are well-defined as are the

special areas where plant life is being restored

(Figure 17)

• Fallen logs are left lying next to hiking trails

and on the forest floor to enhance natural decay

and nutrient cycling (Figure 18).

• Signs are utilized to educate people about the

park's ecosystems (Figure 19).

Developing a Checklist

It's good to look thoughtfully and critically at

our parks, neighborhoods, waterways and other

urban forests to see how they contribute ecologically

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 6

Figure 13. Andrews park has a natural creek running

through it. Photo by Larry Korhnak

Figure 14. Several ponds and other wetland areas

support habitat for wildlife in the park. Photo by Larry

Korhnak

Figure 15. A walkway across one of the wetland areas

offers entry and a look at this ecosystem. Photo by Larry

Korhnak

Figure 16. Fallen leaves and branches maintain a natural

mulch for the park helping to sustain the nutrient cycle in

the ecosystem. Photo by Larry Korhnak

Figure 17. Playground areas are well-defined as are the

special areas where plant life is being restored.

to the community. These benefits can be utilized to

gain support for restoration projects. By using a

checklist we can estimate the benefits for any area

within the urban forest ecosystem.

A Checklist of Wilson and Andrews Parks

shows the contrasting ecological benefits of the two

parks (Figure 20).

Both parks contribute recreational benefits to

the community. The monoculture of loblolly pines

and the hardwood forests at Wilson Park provide

very little biodiversity compared to the natural

ecosystems with many structural layers and plants at

Andrews Park. Parking lots and forests with very

little understory vegetation and natural mulch result

in high levels of stormwater runoff at Wilson Park.

The creek and wetland areas along with the forest

floor with its high water infiltration rates offer

several ways to dispose of stormwater at Andrews

Park. Andrews is a low maintenance, low energy-use

park compared to the high energy levels to maintain

Wilson Park. The removal of all leaves, twigs, and

fallen logs at Wilson Park means that nutrients are

being removed from the site annually; this will

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 7

Figure 18. Fallen logs are left lying next to hiking trails and

on the forest floor to enhance natural decay and nutrient

cycling. Photo by Eliana Kampf Binelli

Figure 19. Signs are utilized to educate people about the

park's ecosystems. Photo by Larry Korhnak

Figure 20. By using a checklist we can estimate the

benefits for any area within the urban forest ecosystem.

This checklist compares the ecological benefits of Wilson

and Andrews parks.

contribute to impoverishment of the site over time.

In addition, organic matter will not be present in the

soil to aid in water and nutrient retention. This

interruption of the natural nutrient cycle can be

remedied easily by retaining fallen plant materials as

in Andrews Park.

And finally, the Socio-Economic category of

benefits. Parks, greenways and natural areas

contribute to the economic health of a community.

For example, before the construction of the Pinellas

Trail (greenway), the city of Dunedin, FL had a 50%

occupancy rate and now with the new greenway,

there are no vacancies (Department of

Environmental Protection 1996). People come or

stay to recreate in communities; wildlife watching

alone generates $18.1 billion in the nation (Caudill

1997). Real estate prices are enhanced with the

presence of natural areas, parks and trees. The

improved psychological well-being of the citizens in

a community or neighborhood with parks and trees

has also been documented (Schroeder and Lewis

1991). People viewing trees have slower heartbeats,

lower blood pressure, and more relaxed brain wave

patterns than people viewing urban areas without

vegetation (Ulrich 1981).

It can be very advantageous to quantify costs

and benefits for maintaining or restoring areas. In

addition to stormwater and energy conservation cost

reductions, other less tangible benefits such as health

and recreation can be demonstrated. Recreational

studies have shown that citizens often prefer

recreating in parks near their homes, emphasizing the

importance of community parks (Schroeder 1990).

In Chicago, 50% of all the people visiting forest

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 8

preserves traveled 10 minutes or less from their

homes (Young and Flowers 1982). In 1996, 2.7

million Floridians participated in wildlife

recreational activities within a mile of their homes

(Florida Game and Fresh Water Fish Commission

1998). It is very important for urban foresters to

demonstrate to their city councils and managing

agencies the importance of parks and trees as

infrastructure in their communities.

Where can We Restore?

The options for restoration sites and projects in

cities and communities are endless. Here are a few:

• Yards can be enhanced with native species or

even native ecosystems (Figure 21).

• Vacant lots, often ignored or treated poorly for

many years, are often candidates for restoration.

• The possibilities for better energy conservation

and stormwater management in shopping center

parking lots are great (Figure 22).

• Street trees, aging or lacking diversity, can be

restored.

• Schoolyards can become natural areas with

unlimited potential as educational areas.

• Industrials parks can be transformed.

• Waterways can be enhanced and connected to

support recreational and hydrological benefits

(Figure 23).

Figure 21. Yards can be enhanced with native species or

even native ecosystems. Instead of a typical

mono-species hedge or a fence, this area between two

neighbors has been restored and planted with native

species.

Figure 22. The possibilities for better energy conservation

and stormwater management in shopping center parking

lots are great.

Figure 23. Waterways such as this creek can be

enhanced with native species and connected to support

recreational and hydrological benefits.

Examples of Sucessful Projects

One objective of this CD-ROM was to find and

showcase successful restoration projects in the U.S.

We have been overwhelmed with the variety and the

high quality of projects being implemented

throughout our cities and communities. There is a

tremendous amount of creativity, ingenuity, and hard

work going into these projects. The high quality and

success are due to the amount of effort by so many

talented people ranging from young children to

funding agency personnel to natural resource

managers and community development

professionals. Partnerships are a common ingredient

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 9

of these projects. As you can see the variety

illustrates the imagination involved and the potential

for even more new projects in other communities.

The Forest Park Ivy Removal Project in

Portland

Sandy Diedrich saw a problem in her

neighborhood park and decided to take the lead in

trying to remedy it. Forest Park, is a 5,000 acre urban

park in Portland, Oregon -- one of the largest urban

forested parks in the country. It has 70 miles of trails

and 30 miles of creeks and tributaries. But it also has

English ivy, a common landscaping plant, which has

invaded the park, covering the native understory

plants and trees, and reducing the biodiversity in the

forest. Controlling the ivy is a challenge - because it

is so mixed with the native plants, herbicides are not

feasible. Instead manual control is necessary (Figure

24). In 1993, Sandy started a program with

volunteers, specifically with high school students

(Figure 25). She developed workshops and

workdays when citizens would come to help. In

addition to eradicating the ivy in the park, the

workshops taught nearby residents methods for ivy

control in their yards - the source of the ivy in the

park (Figure 26). Through their work with this

project, the high school students learned about the

basic ecology of the park, working together as a

team, and the importance of environmental projects

in the community. Alex Johnson, a high school

student and crew leader, noted that, "It's a chance to

make a difference. I've never known about the forest

and here I've learned a lot about nature."

Figure 24. Crew leaders demonstrate ivy removal

methods.

Figure 25. Sandy Driedrich (center) with the crew leaders

(Bruno Precciozzi, Kristin Harman, Alex Johnson, and

Heidi Dragoo) in the headquarters of the Forest Park Ivy

Removal Project.

Figure 26. Standing in front of an area where ivy has been

removed and the forest's natural biodiversity is returning.

Drew Gardens in New York

Ray Emanuel and several others in the Bronx,

New York identified a site in their community that

had potential to be restored. The site was a vacant lot

located next to a school; for years this lot was used

for dumping and even criminal activities. Their goal

was to transform the space into a park for the

community and the school children. This

community-driven initiative including corporations,

the Urban Resources Partnership, and the community

began with planning and clean-up of the site. Fall

clean-ups and spring festivals involve the community

and corporate volunteers. High school students work

at the gardens and this work program is part of a job

protocol educational program (Figure 27). Several

high school classes utilize the gardens for their

instruction including art, language arts (especially

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 10

writing), and science classes. Ecology Days at the

gardens include stations where participants can learn

about subjects such as water testing of the Bronx

River, composting, small wildlife, and edible wild

plants (Figure 28).

Figure 27. A vacant lot located next to a school in New

York was transformed into a park for the community and

the school children.

Figure 28. Included in this new park, named Drew

Gardens, are trails and a deck to view the Bronx River.

Apex Park in Tampa

Apex Park is on Davis Island, a small island in

Tampa. It is the first thing you see after you cross the

bridge to the island. And the residents wanted the

first impression to be the best. So they approached

Steve Graham, Tampa's urban forester for assistance

in restoring the site, a small piece of land about an

acre in size. After researching old photos and

documents and some remnant ecosystems in the area,

they arrived at a list of plants that would have made

up the ecosystem before development of the island

(Figure 29). They were delighted to find one grass,

twisted fiddle leaf, that was endangered and found

some specimens still remaining on the island (Figure

30). They planted a small area with native tree and

shrub species including twisted fiddleleaf. The other

small part of the park was landscaped with grass to

showcase and allow viewing of the native ecosystem

(Figure 31). The park has kindled interest among

residents in native species and several people have

landscaped their yards with many of these species.

Figure 29. With the help of Steve Graham, Tampa's urban

forester, the community of Davis Island restored native

plants at Apex Park.

Figure 30. One plant, twisted fiddleleaf, was endangered

so the community collected specimens and planted it at

the park.

Landscaping for Wildlife

An educational program developed by the

Florida Cooperative Extension Service has given

homeowners the knowledge and tools for

landscaping their backyards and small urban lots for

wildlife using ecological principles (Figure 32).

Workshops are aided by the inclusion of a

participant's guide, instructor's guide and videos

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 11

Figure 31. The other part of the park was landscaped with

grass to showcase and allow viewing of the native

ecosystem.

developed by extension specialists. The first of three

modules entitled "Landscaping for Wildlife:

Providing Food in Your Yard" demonstrates how to

restore a remnant of native landscape, start a

bird-feeding program, control squirrels, plant a wild

bird food plot, and feed hummingbirds and

butterflies. The second module enables participants

to select plants to provide good wildlife cover

including bird and bat houses, burrows for toads and

other small mammals, treefrog houses, rock piles for

lizards and snakes and brush piles for birds and

rabbits (Figure 33). The third module highlights the

importance of the third wildlife requirement - water.

Figure 32. In the Landscaping for Wildlife program,

homeowners learn how to enhance wildlife habitat in their

backyards. Photo by Joe Schaefer

Figure 33. The second module enables participants to

select plants to provide good wildlife cover including bird

and bat houses, burrows for toads and other small

mammals, treefrog houses, rock piles for lizards and

snakes and brush piles for birds and rabbits. Photo by Joe

Schaefer

Naturescaping For Clean Rivers

Landscaping your backyard can have a positive

impact on the environment. That's the theme for

Portland's Naturescaping For Clean Rivers project

(Figures 34 and 35). "Rainwater runoff, or

stormwater, becomes a problem in urban areas

because of the thousands of acres of impervious

surface: roofs, roads, driveways, and parking lots,"

notes the project workbook. This runoff contains

contaminants such as oils, metals, and chemicals.

The goal of naturescaping is to improve the quality

and reduce the quantity of water reaching storm

drains. Workshops teach homeowners how to

landscape with native plants which require much less

water, fertilizers, mowing, and chemicals to maintain

(Figures 36 and 37). Other classes include

composting, attracting wildlife and reducing

pesticide use. Neighbors work together to host

workshops in their communities; all workshop

participants receive project workbooks which help

them develop an action plan for their yard.

Restoring Fire In Haile Plantation

A neighborhood in Gainesville, Florida wanted

to restore the native longleaf pine ecosystem as well

as reduce the fire hazard for their homes. In the past,

fire was a natural disturbance in Florida longleaf pine

ecosystems. Yet, development as well as new forest

practices have excluded fire from many of Florida's

ecosystems. The neighborhood decided to re-instate

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 12

Figure 34. In the Naturescaping for Clean Rivers program

homeowners learn how to landscape with native plants

which require much less water, fertilizers, mowing, and

chemicals to maintain. Here a backyard is prepared for

planting. Photo by Linda Robinson

Figure 35. The backyard is transformed into an energy

and water efficient native landscape. Photo by Linda

Robinson

Figure 36. Native wildflowers adorn a "naturescaped"

backyard. Photo by Linda Robinson

Figure 37. Butterfly gardens are a popular part of the

Naturescaping program. Photo by Linda Robinson

this natural ecological process to the small patches of

forest in their community (Figure 38). Fires reduce

the competing hardwoods allowing longleaf pine to

regenerate and become reestablished in the

ecosystem (Figure 39). Educational signs are a big

part of the program.

Figure 38. A neighborhood in Gainesville, Florida has

brought fire in as a management tool to restore the native

longleaf pine ecosystem as well as reduce the fire hazard

for their homes. Photo by Eliana Kampf Binelli

Greening the Great River Park

The Mississippi River, as with most rivers in the

world, became a center of industry and shipping as

St. Paul, Minnesota became a prosperous city. But

often as with most industrial areas the native forests

along the river were destroyed and replaced with

industrial buildings, pavement, and warehouses. The

Greening the Great River Park Program, established

in 1995, seeks to restore many of these areas along

the River (Figures 40 and 41). This public-private

partnership includes The Saint Paul Foundation, City

of St. Paul and others including thousands of

volunteer and over 240 partner organizations. The

project involves the landscaping of over 100 private

industrial lands with the four native plant ecosystems

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 13

Figure 39. Fires reduce the competing hardwoods

allowing longleaf pine to regenerate and become

reestablished in the ecosystem.

including 30,000 trees and shrubs that occupied the

area in the past. "Our goal is to have a 50% canopy

cover throughout the valley. In 20 to 25 years, as the

trees reach mature heights, we want the valley to

look as though the buildings were placed in a forest

rather than some trees were planted around

buildings."

Figure 40. The Greening the Great River Park Program,

established in 1995, seeks to restore many sites in

industrial areas along the River. This shows an industrial

site before restoration. Photo by Rob Buffler

Figure 41. Over 100 private industrial lands have been

landscaped and planted with four native plant

ecosystems. This shows the same site after restoration.

Photo by Rob Buffler

A Community Park in New York City

A one-acre lot used as a bus garage for many

years and next to three schools was the site for the

birth of a community park in New York City. The

planning began in 1990 with meetings involving the

whole community - city agencies, non-profit

organizations (headed by "Open Road"), students,

businesses, neighbors and more. The grass-roots

park design includes a greenhouse, basketball area,

nature pond with plantings, wildlife area, and

playground (Figures 42). To restore this "brown

field" site the area needed to be lined with plastic and

new soil needed to be imported. However, the group

including professional engineers and school children,

decided to develop a composting system and produce

compost from nearby businesses to produce the

"soil." The newly invented composting system is

now sought by many other communities in New

York. School classes using the park range from

science and gardening to energy and physics to

poetry and art. A math class, for example, helped

design the greenhouse. Paula Hewitt, the project

creator and Open Road Director, emphasizes that

"the purpose of the park is to be educational, yet we

have a very relaxed, fun atmosphere" (Figures 43

and 44). The park is open to the community every

day of the year.

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 14

Figure 42. The planning for this community park in New

York City began in 1990 with meetings involving the whole

community - city agencies, non-profit organizations

(headed by "Open Road"), students, businesses,

neighbors and more. The grass-roots park design

includes a greenhouse, basketball area, nature pond with

plantings, wildlife area, and playground.

Figure 43. Paula Hewitt, the community organizer, looks

for turtles and fish in the park's pond with neighborhood

kids.

Figure 44. Gerald Brinson, who started as a volunteer for

the park and is now part of the staff, describes the new

dock project with flowing water that he is constructing.

Bill Baggs Park

In 1991 Hurricane Andrew struck Miami and its

surrounding communities including Key Biscayne.

Bill Baggs Park which until that time was mostly

occupied with an invasive tree, Australian pine, was

completely destroyed (Figure 45).

Figure 45. In 1991 when Hurricane Andrew struck south

Florida, the non-native Australian pine forest at Bill Baggs

Park on Key Biscayne was completely destroyed.

The nearly clean slate provided an opportunity

and several visionaries saw that it was a possible

chance to restore the park. With partnering between

federal, state, county, city and many non-profit

groups, a proposal and plan was developed to

re-create the park to the way it was 100 years ago.

They researched the five native ecosystems including

four wetland areas that had occupied the site

(Figures 46 and 47).

Historical and recreational amenities were also

considered - for example, without the shade of the

previous forest, nine picnic shelters needed to be

constructed (Figure 48). Cultural history including

archaeological findings were incorporated into the

plan (Figure 49). The ecosystems were restored and

future invasions of non-native plants were monitored

by volunteers. Educational displays were important

to inform the public about the process of restoration

as well as the diversity of the "new" ecosystems

(Figures 50 and 51).

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 15

Figure 46. With partnering between federal, state, county,

city and many non-profit groups, a restoration proposal

and plan was developed to restore the park with the five

native ecosystems that it had 100 years ago. Old

documents were studied to carefully re-create and map

the ecosystems.

Figure 47. The coastal strand ecosystem three years after

planting shows the restoration success.

Figure 48. The shade that had been removed with the

Australian pine tree canopy had to be replaced with

several picnic shelters.

Figure 49. The historical, cultural, and archaelogical

significance of the site such as this 1825 lighthouse with

restored lighthouse-keeper's house was an important part

of the restoration plan.

Figure 50. Involving the park's neighbors and the

community in all the stages was very important to the

restoration success. Nearby condominiums can be seen

from the restored south Florida slash pine ecosystem.

Streamside Restoration in Virginia

The Difficult Run Watershed in Virginia has

over one-half million acres of forests and urban

communities. Nonpoint source pollution is affecting

the water quality of the Difficult Run River and

downstream the Potomac River and Chesapeake

Bay. This restoration project is a partnership with

the Virginia Department of Forestry, Environmental

Protection Agency, Virginia Department of

Conservation and Recreation, Chesapeake Bay

Foundation and the USDA Forest Service. Together

they are striving to:

• Improve water quality by enhancing and

restoring streamside forests.

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 16

Figure 51. Educational displays were important to inform

the public about the process of restoration as well as the

diversity of the "new" ecosystems such as the mangroves

along the ocean and bay.

• Increase public awareness and education

regarding the value of riparian forests.

• Improve fish and wildlife habitat (Figure 52).

Over 8,000 trees have been planted to reestablish

riparian buffers or streamside forests to restore and

maintain this important watershed.

Figure 52. The Difficult Run Watershed Project restores

streamside forests which act as buffers to protect water

quality and fish and wildlife habitat in riparian ecosystems.

Photo by Judy Okay

The Two Key Ingredients

These projects have been very successful

because they all had two key ingredients. First, the

people. All projects became an essential part of the

community because they involved the people in the

community from the start and then in every step.

People included all stakeholders such as citizens (all

ages), businesses, non-profit groups, volunteers, and

government agencies. Collectively these people put

together the second key ingredient to success - a

plan. As you will see in Chapter 5, the successful

restoration plan contains a vision, goal, objectives,

action plans and evaluation tools. Well-developed

plans demonstrate the need for the project and are

used to seek public and financial support. These

plans are usually very effective at obtaining funding

and other in-kind support. Successful projects have

support of the people and a well laid-out plan (Figure

53).

Figure 53. Successful restoration projects have two key

ingredients - support of the people and a well laid-out plan.

Conclusions

There are many options for restoring ecological

benefits in your community. It is important to

consider the whole city or community as an

ecosystem and then to focus in on parcels or projects

that could benefit that ecosystem or landscape as a

whole. Restoration projects can be as small as

Chapter 1: Restoring the Urban Forest Ecosystem: An Introduction 17

backyards to parking lots, city streets, parks,

waterways and any place where there are or could be

trees. Most often it's important to start with a small

manageable project. The United States hosts an

abundance of successful and innovative urban forest

restoration projects. The Bronx's Drew Park brought

life back to a vacant lot next to a school. Portland's

Ivy Project removed invasive ivy at the 5,000 acre

Forest Park. Greening the Great Green River is

restoring industrial parks along the Mississippi

River. The possibilities for restoration projects are

unlimited and up to the imagination and energy of

people (Figure 54). Planning and involving the

community - the stakeholders - are the two most

important ingredients for success.

Figure 54. The possibilities for restoration projects are

unlimited and up to the imagination and energy of people.

Literature Cited

Caudill, A. 1997. 1991 National impacts of non

consumptive wildlife related recreation. Div. of

Economics. US Fish and Wildlife Service.

Arlington. 8 p.

National Research Council. 1992. Restoration

of aquatic ecosystems: science, technology, and

public policy. Committee on Restoration of Aquatic

Ecosystems - Science, Technology and Public Policy,

Water Science and Technology Board, Commission

on Geosciences, Environment, and Resources.

National Academy Press. Washington, D.C. 552 p.

Florida Department of Environmental

Protection. 1996. Environmental Benefits of

Greenways Summary Sheet. 2 p.

Schroeder, H. 1990. Perceptions and

preferences of urban forest users. Journal of

Arboriculture 16(3):58-61.

Schroeder, H. and C. Lewis. 1991.

Psychological benefits and costs of urban forests.

Pages 66-68 In: Proceedings of the Fifth National

Urban Forest Conference. Los Angeles, CA.

Ulrich, R.S. 1981. Natural versus urban scenes:

Some psychophysiological effects. Environment and

Behavior. 13:523-556.

Young, R.A. and M.L. Flowers. 1982. Users of

an urban natural area: their characteristics, use

patterns, satisfactions, and recommendations.

University of Illinois, Department of Forestry,

Forestry Research Report 82-4.

Chapter 2: Basic Ecological Principles for Restoration1

Mary L. Duryea, Eliana Kämpf Binelli, and Henry L. Gholz2

1. This is Chapter 2 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Mary L. Duryea, Professor and Extension Forester, Eliana Kämpf Binelli, Extension Forester, and Henry L. Gholz, Professor, School of Forest Resources

and Conservation, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Traditionally the urban forest has been viewed

as trees in the city - often along streets and in small

groups in other public places such as parks.

However, another way to look at the urban forest is

as an ecosystem, including many more living

components than trees (people, shrubs, herbs,

animals, microorganisms), a physical environment

(light, moisture, soil, rocks), energy flow from the

sun and water and nutrient cycles. A first step in

reorienting our view of urban forests and their

management is to review some important ecological

principles and to see how they apply to restoration

and management. The goal of this chapter is to

examine urban forests as ecosystems and to discuss

some of the opportunities for managing urban forest

ecosystems to provide more natural benefits to

communities and cities. By comparing the present

state of the urban forest ecosystem (UFE) to natural

ecosystems, we can learn how to manage the UFE for

some of the natural benefits it can provide. These

include energy conservation, stormwater

management, wildlife conservation, and recycling or

solid waste management. The urban forest

ecosystem is an open system with energy and

materials constantly entering and leaving the system.

Producers (mainly green plants) and consumers

(organisms dependent on living and dead plant and

animal matter) make up the living portion of all

ecosystems which are linked together in complex

networks called food webs. Cities are largely

consumers relying on production of food, energy and

natural resource from outer agricultural, forested and

other natural areas. The urban forest ecosystem can

provide many opportunities for ameliorating the

drain and stress on our natural resources. For

example, by cooling the city with a forest canopy, we

are less dependent on outside natural resources for

air conditioning. By providing natural areas for

water infiltration, storage and evaporation of

rainwater, the waste water from our streets and other

impervious surfaces is reduced. When leaves,

branches, and grass-clippings are left on-site instead

of being removed, these natural materials sustain the

natural nutrient cycle and provide the same benefits

that we ascribe to mulches in gardens and landscapes.

Urban forests can also help reduce atmospheric CO2

build-up in two ways by reducing fossil fuel (energy)

use and by increasing carbon storage. Finally, the

UFE can provide wildlife habitat and help with the

movement and conservation of some organisms

through connectivity. Seven guidelines to restore and

manage the urban forest ecosystem are: (1) Restore

and manage the UFE to decrease consumption and

contribute to conservation; (2) Restore and manage

Chapter 2: Basic Ecological Principles for Restoration 2

the UFE for its water cycling benefits; (3) Restore

and manage the nutrient cycle within the UFE:; (4)

Restore and manage the UFE to support greater

biodiversity; (5) Restore natural forest ecosystems in

the city; (6) Educate policy makers, city managers

and the public about the benefits of a healthy UFE;

and (7) Incorporate UFE management and

restoration into urban and regional planning.

Introduction

Traditionally the urban forest has been viewed

as trees in the city - often along streets and in small

groups in other public places such as parks (Figure

1). Managing these trees has included inventorying

the tree population and assessing their health. We

have cultured and managed them mostly as

individuals, and this is called arboriculture.

However, another way to look at urban forests is as

ecosystems, with many more components (people,

animals, microorganisms), a physical environment

(sidewalks, soil, rocks), energy flow (sun) and

processes (water, nutrient cycles) (Figure 2). This

ecological perspective is more comprehensive,

incorporating biological, physical, chemical and

social components. This approach offers a great

opportunity to enhance the environmental benefits of

forests in urban areas. The environmental benefits

gained from a healthy urban forest ecosystem (UFE)

include energy savings, reduction of waste and

stormwater costs, water quality improvement,

increased recreational opportunities and enhanced

wildlife and biodiversity conservation. With this

outlook we also have the additional opportunity to

think in the long-term and to consider the urban

forest as part of the larger landscape.

Figure 1. Traditionally the urban forest has been viewed

as trees in the city - often along streets and in small groups

in other public places such as parks.

A first step in reorienting our view of urban

forests and their management is to review some

important ecological principles and to see how they

apply to restoration and management. The goal of

this chapter is to examine urban forests as ecosystems

and to discuss some of the opportunities for

managing urban forest ecosystems to provide more

natural benefits to communities and cities.

Figure 2. Another way to look at the urban forest is as an

ecosystem with many more components (people, animals,

microorganisms), a physical environment (sidewalks, soil,

rocks), energy flow (sun) and processes (water, nutrient

cycles).

The Urban Forest As An Ecosystem

An urban forest ecosystem (UFE) is a collection

of living matter (plants, animals, people, insects,

microbes) and nonliving matter (soil, rocks and dead

organic matter) through which there is a cycling of

nutrients and water and a flow of energy from the

sun. Based on this definition the UFE represents not

only the trees but also the other components

(including humans, microbes, wildlife and the

physical environment) and the interaction of these

components.

What are the boundaries of a UFE? We can

consider UFEs to be the whole city or smaller parcels

within the city. The boundaries of the UFE depend

Chapter 2: Basic Ecological Principles for Restoration 3

on the nature and scope of our management goals.

No matter what the boundaries of the ecosystem are,

each ecosystem is linked to other surrounding

ecosystems (Figure 3). As we noted above, urban

and rural ecosystems also overlap and interact to

form landscapes. All the ecosystems on earth

together form the biosphere, which contains all of the

life on earth.

Figure 3. We can consider the UFE to be the whole city or

smaller parcels within the city depending on our

management goals. The UFE is linked to other

surrounding ecosystems which together form the

landscape.

Why View the Urban Forest

Ecosystem as an Ecosystem?

Cities are part of what used to be rural

landscapes, most of them originally forested (Figure

4).

Figure 4. Cities are part of what used to be rural

landscapes. Here you can see the natural forest edges of

this small city. Photo by Hans Riekerk

By comparing the present state of the urban

ecosystem to natural ecosystems, we can learn how

to manage the UFE for some of the natural benefits it

can provide (Figure 5). These include energy

conservation, stormwater management, wildlife

conservation, and recycling or solid waste

management. Also, by taking an ecosystem view, we

can better understand the importance of the structure

and function of UFEs which may help solve local

problems such as flooding, and air and water

pollution. By focusing on urban ecosystem

management we can also contribute to solving larger

scale problems such as biodiversity conservation and

reduction of atmospheric CO2 concentrations.

Figure 5. By comparing the present state of the urban

ecosystem to natural ecosystems, we can learn how to

manage the UFE for some of the natural benefits it can

provide. Photo by Larry Korhnak

The Structure and Function of the

UFE

The UFE is an open system (in thermodynamic

terms) with materials and energy constantly entering

and leaving (Figure 6).

Energy from the sun is fixed by plant leaves in

the UFE. Some of the absorbed energy then flows

out of the ecosystem as heat, which warms the air

(Figure 7).

The rest of the absorbed solar energy is used to

evaporate or transpire water. Materials entering the

UFE may be in the form of nutrients (fertilizers),

water (in rainfall or irrigation), plants (new plantings

or seeds from invasive plants) or other forms of

non-solar energy, such as fossil fuels (Figure 8).

Chapter 2: Basic Ecological Principles for Restoration 4

Figure 6. The urban forest ecosystem is an open system

with energy and materials constantly entering and leaving

the system.

Figure 7. Energy from the sun is fixed by plant leaves in

the UFE.

Figure 8. Fossil fuels are one of the materials entering the

UFE for management.

Forms of these same materials may leave the

UFE in runoff (storm water), with the wind (seeds)

or in trucks going to landfills (yard and solid waste)

with much converted to CO2 and heat (Figure 9).

Figure 9. Pruned branches and leaves are materials often

leaving the UFE to end up in landfills.

The UFE may have a very complex structure

with a variety of layers including a tree canopy, a

shrub understory, an herb layer and a litter layer. The

UFE is made up of living things, called biotic

components (living plants and animals) and

nonliving things, called abiotic components (soil, air,

nutrients, water, dead organic matter). Nutrients

(such as nitrogen, phosphorus and calcium) and

water cycle from the abiotic parts of the ecosystem

to the biotic parts and back again. These are called

nutrient and water cycling, respectively.

There are two major groups of the living things

in the UFE: (1) producers (also called autotrophs)

and (2) consumers (also called heterotrophs)

(Figures 10 and 11).

Producers, which are mainly green plants, take

light energy and store it through the process of

photosynthesis. Consumers cannot photosynthesize

but instead feed directly on the producers (i.e.,

herbivores) and other consumers (i.e., carnivores or

detritivores or decomposers). Consumers include

non-photosynthetic bacteria, fungi, and animals,

Chapter 2: Basic Ecological Principles for Restoration 5

Figure 10. One of the two major groups of living things in

the UFE is producers (also called autotrophs).

Figure 11. The other major group of living things in the

UFE is consumers (also called heterotrophs) which cannot

photosynthesize but instead feed directly on the producers

(i.e., herbivores) and other consumers (i.e., carnivores and

decomposers).

including humans. Producers and consumers are

linked together in complex networks called food

webs (Figure 12). Food webs are important to

recognize in UFE management, because the

disruption or elimination of one part of the web may

impact other organisms and ecosystem functioning in

unexpected ways.

Figure 12. Producers (mainly green plants) and

consumers (organisms dependent on living and dead plant

and animal matter) are linked together in complex

networks called food webs.

Comparing Natural and Urban Ecosystems

Natural ecosystems have a balance of

production and consumption constantly operating. If

by chance the ecosystem produces more than it

consumes, the excess energy is stored as carbon (in

the wood of tree stems, peat in bogs, etc.). If a fire

or another disturbance lowers plant production, the

consumer populations will adapt accordingly. Cities,

on the other hand, are largely consumers relying on

production of food, energy and natural resources in

outer agricultural, forested and other natural areas

(Odum 1983) (Figure 13). Seldom do cities produce

these necessities within their perimeter in quantities

sufficient to support large numbers of people. At the

same time, cities must contend with the wastes that

are produced, often sending solid wastes and waste

water out of the city.

Figure 13. Cities rely on natural and domesticated

environments for resources. At the same time these cities

must contend with the wastes that are produced, often

sending solid wastes and waste water out of the city

(adapted from Odum 1983).

Chapter 2: Basic Ecological Principles for Restoration 6

How Can the UFE Help?

The urban forest ecosystem can provide many

opportunities for ameliorating the drain and stress on

our natural resources. For example, by cooling the

city with a forest canopy, we are less dependent on

outside natural resources for air conditioning (Figure

14).

Figure 14. By cooling the city with a forest canopy, we are

less dependent on outside natural resources for air

conditioning. Photo by Hans Riekerk

By providing natural areas for water infiltration,

storage and evaporation of rainwater, the waste water

from our streets and other impervious surfaces is

reduced (Figure 15).

Figure 15. By providing natural areas for water infiltration,

storage and evaporation of rainwater, the waste water

from our streets and other impervious surfaces is reduced.

Photo by Larry Korhnak

By providing places for recreation, fewer people

will need to use fossil fuels to leave the city for their

nature experiences (Figure 16).

Figure 16. By providing places for recreation, fewer

people will need to use fossil fuels to leave the city for

their nature experiences. Photo by Larry Korhnak

By supporting, for example, water quality,

forest management, and growth management policies

for lands outside our cities, we will sustain our

natural and domesticated ecosystems. Infusing our

cities and communities with more urban forest

ecosystems will restore natural structure and

processes to our urban forests making us less

dependent on our limited natural resources outside

the city.

Characteristics of the UFE

The Urban Heat Island

Cities can reach temperatures 7o to 15o F higher

than in the surrounding rural ecosystems. This is

called the urban heat island effect (Figure 17).

Figure 17. A city is 7o to 15o F warmer than the

surrounding countryside. Adapted from Oke 1982.

Chapter 2: Basic Ecological Principles for Restoration 7

Some of the reasons for this heat buildup are:

(1) cities generate heat from burning fossil fuels

(factories, cars, heating and air conditioning),

(2) city structures absorb and store solar heat

(especially dark surfaces such as asphalt roads and

dark roofs),

(3) through decreased vegetation and rapid

routing of rainwater to storm sewers, cities have

much less natural cooling due to the evaporation and

transpiration of water,

(4) air pollutants may slow the outflow of heat

away from urban surfaces, and

(5) cities usually have less air movement to take

heat out of the city (Lowry 1967; Oke 1982).

Large numbers of trees can reduce local air

temperatures by 1o to 9o F (McPherson 1994).

Evapotranspiration by trees lowers air temperatures

in two ways. First, when precipitation is intercepted

by trees and other plants, the evaporation of this

water cools the air. Secondly, trees constantly take

up water from the soil and lose water to the air. This

process, called transpiration, also lowers air

temperature. Therefore, the UFE can reduce heat

buildup in the city by storing less heat, using more of

the sun's energy for evaporative cooling, and shading

buildings and other surfaces so that they require less

fossil fuel energy for cooling (Figures 18 and 19).

Figure 18. The urban forest ecosystem through

evaporative cooling and shade can contribute to reducing

the temperatures in the urban heat island. This parking lot

is a contributor to high temperatures in the urban heat

island.

Figure 19. The urban forest ecosystem through

evaporative cooling and shade can contribute to reducing

the temperatures in the urban heat island. This parking lot

demonstrates trees properly placed to reduce temperature.

Nutrient Cycling in the UFE

Chemicals circulate from the plants and animals

to the soil and back again, as part of the nutrient

cycle (Figure 20). The health of plants in the

ecosystem is mainly dependent on the soil for its

source of nutrients. Dead organic matter in the soil,

also called detritus, is the long-term storage site for

essential nutrients. Decomposers (primarily

microrganisms) break down the detritus and release

the nutrients held in the organic matter into organic

forms that can be reused by plants, thus completing

the nutrient cycle. In the UFE, this cycle is often

disrupted or arrested because most of the dead

organic material such as lawn clippings, leaves,

branches, and logs are removed and hauled to landfill

sites or chipped for application to other sites. By

doing so, we are denying the UFE of a readily

recyclable source of fertilizers, which then must be

imported in the form of man-made fertilizers.

What happens when we remove these natural

materials from a backyard, a park, or a schoolyard in

the UFE?

• the soil may be exposed, resulting in erosion,

• plant roots may be exposed and desiccated or

damaged (Figure 21),

• fossil fuels are used to blow leaves, clean the

site and transport the yard waste to landfills or

compost piles (Figure 22),

Chapter 2: Basic Ecological Principles for Restoration 8

Figure 20. Chemical elements in ecosystems circulate

from the plants and animals to the soil and back again, as

part of the nutrient cycle.

• the organic matter removed no longer helps the

moisture and nutrient holding capacity of the

soil,

• wildlife and other organisms that depend on

decaying wood or litter for habitat and/or food

cannot live in this neatly maintained

environment,

• precious plant nutrients are removed often

requiring fertilizer applications for replacement

(Figure 23),

• fertilizers, water, mulches, and pesticides

brought in to support and maintain this altered

system are manufactured at a great fossil fuel

cost.

Figure 21. When natural plant materials are removed from

a landscape, many plant roots may be exposed and

desiccated or damaged.

Figure 22. Many leaves and branches that could be piled

or spread (recycled) in a homeowner's landscape are

instead transported to landfills or urban compost piles.

Figure 23. Precious plant nutrients are removed from the

landscape either resulting in plant deficiencies or requiring

fertilizer applications.

Instead of using tremendous amounts of energy

to remove branches, leaves, and snags, we can utilize

these materials to sustain the health of the UFE.

These natural mulches can be recycled on-site for

free where they will serve as natural fertilizers.

When they remain on-site, these natural materials

provide all the benefits that we ascribe to mulches in

gardens and landscapes (Figure 24).

It is quite feasible to take advantage of natural

nutrient cycling processes in UFE, contributing in the

process to conservation (water, energy, and soil) and

improving the environment both locally and globally.

Landscapers need to change many ingrained

practices, such as leaving more dead plant materials

on the ground. Creating "natural" or "semi-natural"

Chapter 2: Basic Ecological Principles for Restoration 9

Figure 24. When leaves, branches, and grass-clippings

are left on-site, these natural materials provide all the

benefits that we ascribe to mulches in gardens and

landscapes.

areas in parks, backyards and other appropriate sites

will have favorable results for nutrient cycling and

other UFE processes such as cycling.

Water Cycling in the Urban Forest

Water forms a critical link between the earth's

surface and the atmosphere. After water falls to earth

as rain (and in other forms), it flows downhill into

creeks or soaks into ground, entering the ground

water (Figure 25).

Figure 25. In the water cycle, water falls to the earth as

precipitation, enters the ground or flows as runoff to rivers,

lakes and the ocean, and is taken up (used) by plants and

other organisms. By evaporation from vegetation, land

and bodies of water, water re-enters the atmosphere to

begin the cycle once again.

Water in creeks flows into rivers, lakes and

finally the ocean. Water reenters the atmosphere by

evaporation from the land and sea and and by

evaporation and transpiration from vegetation (see

Chapter 6 - The Hydrological Cycle). In the UFE,

impervious surfaces such as buildings, paved streets

and parking lots interrupt this water cycle by

collecting the water and channeling it into sewers,

canals and other structures.

The consequences of interrupting the natural

water cycle include:

1. decreased infiltration of water into soil,

2. more runoff, which must then be managed and

accomodated,

3. decreased water quality as pesticides, fertilizers

and other polluants are concentrated in the

collected runoff,

4. erosion of unprotected soils and

5. less evaporation of water with its associated

cooling effect.

How does the UFE help restore the water cycle?

First, vegetation in the UFE intercepts rainfall and

evaporation of this water helps cool the city. Second,

soils absorb water; then it is either taken up by plants

or percolates to the water table or creeks instead of

running into storm sewers. The result is lower

stormwater treatment costs and less flooding

potential in the city (Figures 26 and 27).

Figure 26. In the city, impervious surfaces such as

buildings, paved streets and parking lots interrupt the

water cycle by collecting the water and channeling it into

sewers, canals and other structures. Photo by Larry

Korhnak

Chapter 2: Basic Ecological Principles for Restoration 10

Also, if soils are protected with mulches and

plants, less erosion will result in less sediment

entering the water. Wetlands also serve as storage

areas for water. Restoring and managing wetlands in

cities will lower the rate and volume of stormwater

runoff, control floods and erosion and help purify

water that will reach the water table. For example,

after storm in Dayton, Ohio the existing urban forest

reduced runoff by 7%. A slight increase in the urban

forest canopy could reduce runoff by 12% (Sanders

1984).

Figure 27. Soils in the UFE absorb water; then it is either

taken up by plants or percolates to the water table or

creeks instead of running into storm sewers. Photo by

Larry Korhnak

Educating policy makers, city managers and the

public about the benefits of vegetation in the UFE

and cost-saving potential is essential to more efective

management of the water cycle. For further

discussion on the water cycle, see Chapter 6- The

Hydrological Cycle.

Carbon Storage and Sequestering by UFEs

Carbon dioxide (CO2) in the atmosphere is

increasing globally and is the principal contributor to

the expected increase in the greenhouse effect

(global warming). The two main sources of CO2 are

the burning of fossil fuels and deforestation

(Houghton et al. 1996). Trees, litter, soil and organic

matter all store carbon (C). Since organic matter

contains 50% C, the more biomass (plant and animal

matter) on the earth, the less CO2 in the atmosphere.

In an ecosystem, carbon is taken in as CO2 in

the process of photosynthesis (Figure 28). Carbon is

either stored as living or dead plant material or

consumed by other organisms in the food web. CO2

is also given off during respiration. Forests can store

much greater amounts of C in the vegetation and

soils than any other type of ecosystem on earth due

mainly to the relatively massive storage in tree stems.

Figure 28. In an ecosystem carbon is taken in as CO

2

in

the process of photosynthesis. Carbon is either stored as

living or dead plant material or consumed by other

organisms in the food web. CO

2

is also given off during

respiration.

Can the UFE help to store more carbon? Forests

store carbon in their plants, roots, forest litter and

animals. One urban study estimated that the 69

million acres of urban forest in the U.S., with an

average of 28% canopy cover, store annually a net

6.5 million tons of C (Rowntree and Nowak 1991).

However, the whole world puts out 5.4 billion tons C

per year (deforestation alone accounts for 1.6 billion

tons) (Sundquist 1993). Urban forests in the USA

therefore currently only remove 0.1% of the output.

Even though urban forests are not likely to be better

managed just for C sequestration, it is important to

recognize that C sequestration by the UFE is an

additional benefit, albeit small.

To summarize, the UFE can contribute to reduce

atmospheric CO2 in two ways: First, by reducing

fossil fuel (energy) use in the cities (Figure 29);

Second, by increasing C storage from planting and

managing trees especially in cities where tree cover

is currently low.

Chapter 2: Basic Ecological Principles for Restoration 11

Figure 29. The UFE can contribute to reduce atmospheric

CO

2

by reducing fossil fuel (energy) use in the cities.

Wildlife in the UFE

Urbanization and urban sprawl have resulted in

habitat loss, highly fragmented forests, drained

wetlands and disrupted migration routes for wildlife.

Also, in many situations wildlife is dependent upon

two or more ecosystems, and these may not be

available. A forest fragment is a small parcel

separated from the larger forest (see also Chapter 3

- Biodiversity). In the UFE, forest fragments often

become small parks or undeveloped and often

degraded land. These fragments may be too small or

too distant to support many wildlife species

characteristic of natural areas. However, by

connecting some smaller fragments, larger

ecosystems can be simulated and some migration

routes and habitats restored (Figures 30 and 31). For

further discussion on wildlife, see Chapter 8 -

Wildlife.

Figure 30. This creek outside of a small city is connected

to a wetland inside the city allowing migration of some

wildlife species. Photo by Hans Riekerk

Figure 31. By connecting some smaller fragments, larger

ecosystems can be simulated and some migration routes

and habitats for wildlife may be restored. Photo by Larry

Korhnak

Biodiversity

Until recently, efforts in biological conservation

have largely focused on preservation and protection

of individual species, subspecies and populations,

through the implementation of the Endangered

Species Act. However, scientists and practitioners

are realizing today that this has not always been

successful or even possible, and that many other

species have been ignored as a result. More recently

there is a greater focus on ecosystem management

with the idea that by managing and restoring whole

ecosystems, biodiversity and whole food webs, as

well as individual species, may be better protected.

Urban forests, which range from highly degraded

woodlots to monocultures of exotic trees to

semi-natural ecosystems, may play an important role

in managing for biodiversity. Although urban forests

cannot be expected to support all species groups (for

example large mammals or other wide-ranging

animals), if effectively managed, they can provide

habitat at a smaller scale, increase the effectiveness

of larger nearby reserves, and help with the

movement and conservation of some organisms

through enhanced connectivity (Figure 32).

Thus urban forests can be "stepping stones

between ecosystems" (Franklin 1993) (Figure 33).

At a smaller scale, biodiversity can also be restored

by enhancing the ecosystem's natural structure,

creating multi-age ecosystems in several stages of

succession, controlling invasive plant and animal

species, leaving stumps, leaves, snags and logs to

Chapter 2: Basic Ecological Principles for Restoration 12

Figure 32. Although urban forests cannot be expected to

support all species groups (for example large mammals or

other wide-ranging animals), if effectively managed, they

can provide habitat at a smaller scale, increase the

effectiveness of larger nearby reserves, and help with the

movement and conservation of some organisms through

enhanced connectivity. A corridor of forest provides this

connectivity. Photo by Henry Gholz.

improve nutrient cycling and for wildlife and by

planting native species that mimic composition of

nearby ecosystems. (For further discussion, see

Chapters 3 - Biodiversity, 4 - Plant Succession and

Disturbances, and 9 - Invasive Plants.)

Figure 33. Urban forests can be "stepping stones

between ecosystems" (Franklin 1993).

Opportunities for Restoring and

Managing the UFE More

Ecologically

How can we restore and manage the urban forest

ecosystem? We propose the following seven

guidelines:

Restore and manage the UFE to decrease

consumption and contribute to conservation:

• Take advantage of natural nutrient cycling

by leaving grass clippings, leaves, branches

and logs on the ground and thereby reduce

the tremendous amount of energy expended

to remove plant materials from the

landscape.

• Plant and maintain trees around buildings

to reduce energy consumption for cooling

and heating.

• Save energy used for stormwater

management by increasing areas within the

UFE for water infiltration and evaporation.

• Manage the UFE to encourage recreation

in the city, thereby decreasing energy

consumption for travel to distant recreation

sites.

• Plant tree species that are adapted to local

conditions and require only natural rainfall

(after establishment) to save water and

energy costs from irrigation.

Restore and manage the UFE for its water

cycling benefits:

• Decrease storm water runoff and flooding

by increasing pervious surfaces (soils) in

the city to absorb water.

• Encourage increased canopy and

vegetation for increased evaporation and

transpiration of water to decrease

stormwater runoff and treatment costs.

Chapter 2: Basic Ecological Principles for Restoration 13

• Increase the retention of water in the UFE

for evaporative cooling to lower urban heat

island temperatures.

• Increase soil water infiltration in UFE soils

along with the retention of sediments and

pollutants to improve water quality.

• Restore and manage wetlands in cities to

lower the rate and volume of stormwater

runoff, control floods and erosion and help

purify water that will reach the water table.

Restore and manage the nutrient cycle within

the UFE:

• Leave grass clippings, leaves, branches

and logs on the ground to decompose and

provide nutrients.

• Use less fertilizers by taking advantage of

nutrients that naturally exist and cycle

through the system.

• Rake and distribute on-site mulch in the

UFE to protect the soil, retain moisture and

increase the nutrient holding capacity of the

soil.

• Plant less nutrient-demanding species.

Restore and manage the UFE to support

greater biodiversity:

• Include many different species and life

forms (herbs, shrubs, trees) in the UFE to

provide wildlife habitat and resist

disturbances.

• Restore small ecosystems (with their

structure and function) as important

connections in the landscape.

• Restore and manage waterways to connect

with other ecosystems.

Restore forest ecosystems in the city:

• Take a role in restoring natural ecosystems

by establishing one on a vacant lot, in a

schoolyard, at a park or another potential

site.

• Restore smaller model ecosystems to serve

as demonstration sites for restoration and

ecology education.

• Educate people about the UFE by restoring

or improving the health of degraded

ecosystems.

• Reduce deforestation by encouraging

developers to retain more green space or

larger forest areas in their developments.

Educate policy makers, city managers and the

public about the benefits of a healthy UFE:

• Cost-savings benefits,

• Recreation opportunities,

• Tourism benefits of healthy UFE's,

• Energy-saving,

• Wildlife conservation,

• Benefits to natural cycles and recycling,

• Water quality improvement,

• Stormwater management, and

• Carbon sequestration.

Incorporate UFE management into urban

and regional planning:

• Demonstrate how the UFE will benefit

regional environmental, economic and

social health.

• Be involved in the planning process to

incorporate UFE management into plans.

• Educate people to think about the UFE

when developing new areas and in

downtown redevelopment projects.

• Consider and educate people about the

ecological, economic and social benefits of

the UFE at the local to global scale.

Chapter 2: Basic Ecological Principles for Restoration 14

Additional Readings

Chameides, W.L., R.W. Lindsay, J. Richardson,

and C.S. Kiang. 1988. The role of biogenic

hydrocarbons in urban photochemical smog: Atlanta

as a case study. Science 241:1473-1476.

Gilbert, O.L. 1989. The ecology of urban

habitats. Chapman and Hall, NY.

Gill, D. and P. Bonnett. 1973. Nature in the

urban landscape: A study of city ecosystems.

Baltimore: York Press.

Goldman, M.B., P.M. Groffman, R.V. Pouyat,

M.J. McDonnell, and S.R.A. Pickett. 1995. CH4

uptake and N availability in forest soils along an

urban to rural gradient. Soil Biological Biochemistry

27(3):281-286.

Lyons, T.J., J.R. Kenworthy, and P.W.G.

Newman. 1990. Urban structure and air pollution.

Atmospheric Environment 24B:43-48.

Naiman, R.J., Décamps, H. and M. Pollock.

1993. The role of riparian corridors in maintaining

regional biodiversity. Ecological Applications

3(2):209-212.

Vitousek, P.M., P. Ehrlich, A. Ehrlich, and P.M.

Matson. 1986. Human appropriation of the products

of photosynthesis. Bioscience 36:368-373.

White, C.S. and M.J. McDonnell. 1988.

Nitrogen cycling processes and soil characteristics in

an urban versus rural forest. Biogeochemistry

5:243-262.

Cited Literature

Akbari, H., S. Davis, S. Dorsano, J. Huang, and

S. Winnett. 1992. Cooling our communities: A

guidebook on tree planting and light colored

surfacing. US Environmental Protection Agency and

Lawrence Berdeley Laboratory Report LBL-31587.

Franklin, J.F. 1993. Preserving biodiversity:

Species, ecosystems, or landscapes? Ecological

Applications 3:202:205.

Houghton, J.T., L.G. Meira Filho, N. Callander,

N. Harris, A. Kattenberg, and K Maskell. (eds.)

1996. Climate change 1995, the science of climate

change. Working Group 1, Intergovernmental Panel

on Climate Change, Cambridge University Press.

Lowery, W.P. 1967. The climate of cities.

Scientific American 217:15-23.

McPherson, E.G. 1994. Energy-saving potential

of trees in Chicago. In Chicago's urban forest

ecosystem: Results of the Chicago Urban Forest

Climate Project, edited by E.G. McPherson, D.J.

Nowak, and R.A. Rowntree. Gen. Tech. Rep.

NE-186. Radnor, PA: USDA Forest Service,

Northeast Forest Experiment Station.

Odum, E.P. 1983. Basic ecology. Fort Worth,

TX: Saunders College Publishing.

Odum, E.P. 1993. Ecology and our endangered

life support systems. Sunderland, Massachusetts:

Sinauer Associates, Inc.

Oke, T.R. 1982. The energetic basis of the urban

heat island. Quarterly Jounal of the Royal

Meteorological Society 108:1-24.

Rowntree, R.A. and D.J. Nowak. 1991.

Quantifying the role of urban forests in removing

atmospheric carbon dioxide. Journal of

Arboriculture 17:269-275.

Sanders, R.A. 1984. Urban vegetation impacts

on the urban hydrology of Dayton Ohio. Urban

Ecology 9:361-376.

Sundquist, E.T. 1993. The global carbon

dioxide budget. Science 259:934-941.

Chapter 3: Biodiversity and the Restoration of the Urban

Forest Ecosystem1

Eliana Kämpf Binelli2

1. This is Chapter 3 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Eliana Kämpf Binelli, Extension Forester, School of Forest Resources and Conservation, Cooperative Extension Service, Institute of Agricultural

Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Biodiversity is the variety of life and all the

processes that keep life functioning. Global

biodiversity provides many ecosystem services, such

as protection of water resources, nutrient storage and

cycling, and pollution mitigation. These ecosystem

services have recently been estimated to provide $33

trillion per year. Biodiversity occurs at many levels

from genetic diversity to species diversity to

ecosystem diversity. Biodiversity has been reduced

in urban areas through ecosystem destruction,

degradation and fragmentation of remaining

ecosystems. Biodiversity can be increased in urban

areas by managing the landscape as a whole and

improving connectivity between ecosystem

fragments. Biodiversity can also be restored by (i)

leaving stumps, leaves, snags and logs to improve

nutrient cycling and for wildlife, (ii) planting native

species that mimic composition of nearby

ecosystems, (iii) controlling invasive plants and

animals, (iv) enhancing the ecosystem's natural

structure, and (v) creating multi-age ecosystems in

several stages of succession. Ecological processes to

restore include natural disturbances (e.g., fire),

ecological succession, nutrient cycling and

hydrological cycling.

Introduction

While watching TV, reading newspapers,

listening to the radio or even talking to friends, we all

have heard something about biodiversity. Issues

such as old-growth forests and the spotted owl,

tropical deforestation, hunting of whales and many

other topics related to biodiversity have made the

news.

Biodiversity has emerged as one of the key

environmental concerns in the debate over the

worldwide depletion of natural resources.

Biodiversity is now a matter not only of scientific

interest but also public concern throughout the

world.

But, what exactly is biodiversity? Why is it

important? Are urban forests important to the

conservation and maintenance of biodiversity? Why

should urban foresters, citizens, policy makers and

professionals be concerned about biodiversity in

urban areas? Can we restore biodiversity in our

cities? How? This publication will discuss these

questions and how managers can incorporate

biodiversity into urban forest restoration projects.

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 2

What Is Biodiversity?

Biodiversity, the short term used for biological

diversity, is "the variety of life and all the processes

that keep life functioning" (Keystone Center 1991).

Biodiversity includes 1) the variety of different

species (plants, animals - including humans,

microbes and other organisms), 2) the genes they

contain, and 3) the structural diversity in

ecosystems.

The wealth of biodiversity supports ecological

processes which are essential to maintain ecosystems

on earth (Figure 1). Examples of such ecological

processes are the nutrient cycle, the hydrological

cycle, and natural succession.

Figure 1. The exact number of existing species in the

world is unknown, with estimates varying from as low as 5

million to as high as 100 million species. Most are insects

that play critical roles in ecosystems such as

decomposition and nutrient cycling.

One of the most fundamental attributes of

biological diversity is that it is always changing. The

wealth of biodiversity is the product of hundreds of

millions of years of evolutionary history. The

process of evolution means that the pool of living

diversity is dynamic and constantly changing.

Climatic, geologic, hydrologic, ecological and

evolutionary processes generate biodiversity and

keep it forever changing (Noss and Cooperrider

1994). We explore this issue with more details in

Chapter 4 - Succession and Disturbances.

Levels of Biodiversity

Let's explore in more detail how biodiversity

occurs in ecosystems. The key to an effective

analysis of biodiversity is the definition of each level

of organization that is being addressed.

Biodiversity is usually considered at three

different nested levels: 1) gene, 2) species and 3)

ecosystem. Changes in one level of biodiversity may

have impact on the next level and vice-versa. For

example, imagine that an exotic disease (Dutch elm

disease or Chestnut blight) is introduced to an urban

forest with low species diversity (mostly elms or

chestnut trees). Since the genetic pool of these urban

forests is limited to species susceptible to these

diseases, not only individual species will be affected

but also the whole ecosystem to which these species

belong.

Gene level

Biodiversity at the genetic level refers to the

information contained in the genes of all individual

plants, animals and microorganisms. This level of

biodiversity is critical in order for species to adapt to

changing conditions and to evolve.

Restoration ecologists usually recognize the

genetic level of biodiversity in restoration projects.

For example, after Hurricane Andrew struck in South

Florida in 1992, all the Australian pines (Casuarina

equisitifolia) were destroyed in Bill Baggs, a heavily

used urban park in Miami. Prior to the hurricane,

Australian pine, which is a highly invasive species,

covered a large portion of the park. The natural

removal of Australian pines by the Hurricane

provided a great opportunity to restore the park to

conditions closer to its previous natural conditions.

In this project, it was recommended that seeds be

collected from local ecosystems within 50 miles

radius of Bill Baggs in order to ensure a well-adapted

genetic pool to the climate and soils of this specific

location (Figure 2).

Species level

This level is what most people have in mind

when they think about biodiversity. Most simply,

species diversity is the number of species present in

an area. However, the specific combination of

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 3

Figure 2.1 Photo by Mary Duryea

Figure 2.2 Photo by Mary Duryea

Figure 2. The Bill Baggs Cape Florida Restoration

Project, considered the genetic level of biodiversity by

collecting genetic material from areas representative of

the region's ecosystems. Several small ecosystems were

restored including wetlands (2.1), and uplands (2.2).

species and their relative abundance are also

important considerations.

It is common in many cities across the US to

find neighborhoods where streets are all planted with

the same tree species. In fact, if we consider even

the whole city, we would find only a few species

planted over and over again. The diversity of street

tree species is critically low in many U.S. cities and

towns (Sun 1992). In Oakland CA, for example,

only four species make up 49 percent of the tree

population (Nowak 1993), and in Chicago IL, six

species or genera constitute more than half of the

population (Nowak 1994).

A classic example of problems associated with

lower species diversity is the extensive use of

American elm (Ulmus americana) as a street and

urban tree in U.S. cities after World War II.

American elm constituted 95 percent of all street

trees (200,000 elms) in Minneapolis MN, for

instance (Price 1993). When Dutch elm disease, a

fungus spread by bark beetles that causes wilting and

dieback of elms, was introduced in the late 1960's,

nearly all American elms were killed in Minneapolis

and in the rest of the country (Figure 3). Besides the

obvious aesthetic problems, this lack of biodiversity

necessitated major and expensive efforts to eradicate

and dispose of the killed elm trees.

Figure 3.1 Photo by Mary Duryea

The Dutch elm disease outbreak and the loss of

virtually all American elms illustrate the

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 4

Figure 3.2 Photo by Edward Gilman

Figure 3. American elms (Ulmus americana), were once

extensively planted in streets and parks in many cities and

towns across the U.S. (3.1). The introduction of Dutch elm

disease killed nearly all the elms (3.2) and reminds us that

the species level of biodiversity is critical when managing

urban forests.

consequences of lack of species diversity. Besides,

by planting only a few tree species or genera, the age

diversity of the species planted may be extremely

reduced. The end result of this practice is many old,

decaying trees to be removed, pruned and managed

at the same time, increasing the city's or

municipality's tree maintenance costs.

Biodiversity can be enhanced at the species

level by simply increasing the number of different

tree species planted (preferably native species

present in natural ecosystems in the region).

Additionally, by planting species each year instead of

all in one year, the age diversity in urban forests can

also be increased.

Ecosystem level

The structure of the urban forest is an important

biodiversity consideration at the ecosystem level.

Structure in forests is characterized by the nature and

abundance of the various vegetation layers (canopy,

subcanopy, shrub layer and ground cover) and the

presence of dead logs and snags. It is important that

ecosystems retain their natural structure.

In most ecosystems, a greater structural

diversity will support a greater diversity of wildlife

and will ensure better ecosystem functioning. A

forested ecosystem should have snags (dead standing

trees) (Figure 4) and logs (Figure 5), which provide

habitat for small mammals, amphibians and reptiles

and food for many insects and fungi (which in turn

are food for birds).

Figure 4.1

Structural diversity should be reintroduced in

restoration projects. There are several ways in which

this can be accomplished. For example, a snag can

be created by cutting a hazard tree but leaving a taller

stub to decay. Many urban forest restoration projects

also import logs and snags by salvaging trees in areas

slated for development. These trees are then used as

either downed logs or "planted" back in the ground

like giant posts to decay, increasing the structural

diversity and enhancing nutrient cycling.

Why Is Biodiversity Important?

Recently, all natural ecosystems on earth have

been estimated to provide $33 trillion annually in

ecosystem services (Costanza et al. 1997). This is

twice the combined gross domestic product of all

nations in the world. Ecosystem biodiversity

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 5

Figure 4.2

Figure 4. Snags provide important ecosystem structure.

They are habitat for birds (4.1), mammals, termites,

insects, frogs and several microorganisms and are also

important for the nutrient cycle (4.2).

Figure 5. In a natural forest, there will be snags and logs

in different stages of decay. Different living organisms use

these different stages.

provides us with these services, which include the

protection of water resources, nutrient storage and

cycling, pollution bioremediation (biologically based

environmental cleanup), maintenance of ecosystems,

soil formation, climate regulation and other natural

processes, recreation and food production.

Biodiversity occurs at several spatial scales

(locally, regionally, globally). This means that

biodiversity has significance at a global scale as well

as in our own city backyards. Some of the values

associated with biodiversity include:

• ecosystem functioning,

• future value, and

• educational and recreational benefits.

Ecosystem functioning

When ecosystems are diverse, there is a range of

pathways for many ecological processes and for

primary production. If one of these pathways is

damaged or destroyed, an alternative pathway may

be used and the ecosystem can continue functioning

(Kimmins 1996). For example, when a particular

bacteria species is missing from the nutrient cycle, in

a diverse ecosystem, another organism may be

present to carry out the same function (Figure 6).

However, some organisms, such as top predators,

also play an important role in ecosystem functioning

but cannot be easily replaced. In any case, if the

biological diversity is greatly diminished, the

functioning of the ecosystem may be at a risk.

The associated costs of losing the ability of

ecosystems to function are extremely high. The

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 6

Figure 6. An example of ecosystem services is the

decomposition of organic matter by microorganisms and

other species, such as these fungi. Photo by Larry Korhnak

degradation of wetlands is a dramatic example of the

problems associated with loss of ecosystem

biodiversity. Floods, problems in water quality and

quantity for natural and human systems, and declines

in fish and wildlife populations, have all been linked

to wetlands destruction, degradation and

fragmentation. The Everglades is an extensive

ecosystem in Florida which currently faces such

problems. Costs for restoring natural ecosystem

services and biodiversity to the Everglades have been

estimated to be hundreds of million of dollars.

Congress recently approved the expenditure of $1.5

billion to restore only some areas of the Everglades

(South Florida Ecosystem Task Force 1998).

Future value

Natural ecosystems are a reservoir of continually

evolving genetic material, irrespective of whether

their values have been recognized. The same genetic

material may have important but yet to be discovered

medicinal, economic, aesthetic, recreational or

intrinsic values for future generations.

An example of one of the most promising

discoveries in recent years has been taxol, which was

initially isolated from the Pacific yew (Taxus

brevifolia Nutt.), a tree species in the Douglas-fir

forests of the Pacific Northwest that was until

recently considered unimportant (Figure 7). Taxol

has been used in the treatment of ovarian and breast

cancers. In the U.S., approximately 25% of all

prescriptions contain active ingredients derived from

plants (Principe 1989).

Figure 7. The bark of Pacific yew (Taxus brevifolia Nutt.)

trees contains taxol, a new drug for treating several forms

of cancer. Photo by Dr. AC Mitchell

Biodiversity is also essential in biological

control and for the breeding of disease resistant

species. Use of genetically resistant plant species for

food production, clothing, commercial and urban

forestry is derived from a wide array of diverse

native species.

Educational and recreational benefits

One of the most important reasons to manage

and protect biodiversity in urban centers is their

educational and recreational values. Recreational

benefits are perhaps the most important value of

biodiversity in urban areas. People value natural

areas for a variety of reasons: psychological

renovation through contact with nature, jogging and

hiking, birdwatching, photographing, and many

other activities. The aesthetic value of ecosystems

also contributes to the emotional and spiritual

well-being of a highly urbanized population (Figure

8).

Figure 8.1 Photo by Mario Binelli

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 7

Figure 8.2 Photo by Mario Binelli

Figure 8. Recreational benefits of biodiversity are closely

related to aesthetic, psychological (8.1 and 8.2) and

educational values.

In 1991, 30 million Americans participated in

wildlife watching and another 14 million adults went

fishing (U.S. Fish and Wildlife Service 1992).

Nationwide, wildlife viewers spent $18 billion

(Norris 1992). Watchable wildlife recreational

activities provide local economies with important

income generated by sales, employment and tax

revenues. For example, Florida's watchable wildlife

generated $3.5 billion in 1996 (Florida Game and

Fresh Water Fish Commission 1998).

Some ecosystems, especially those close to

metropolitan centers are becoming extremely rare.

For example, Florida's scrub ecosystems are now

surrounded by the greater Orlando urban area and are

threatened by human encroachment and

development. Ultimately, it will be up to these urban

citizens to protect such ecosystems and their benefits.

In this case, there is some evidence that the Florida

scrub jay, an endangered bird in the scrub ecosystem,

may persist in residential areas, provided adequate

patches of the scrub ecosystem remain preserved

nearby. (Florida Game and Fresh Water Fish

Commission 1997). These urban remnant

ecosystems could be powerful tools for educating

urban citizens about the importance and value of

such diverse ecosystems (Figure 9).

Figure 9.1

Figure 9.2 Photo by Larry Korhnak

Figure 9. Managing for biodiversity in urban areas is an

excellent opportunity for integrating ecological,

educational (9.1) and recreational values (9.2).

Increasing urbanization accelerates human

pressures on remaining natural ecosystems. At the

same time, however, recreational spaces have to be

managed for this increasing population. In 1996, 2.7

million Floridians participated in wildlife

recreational activities within a mile of their homes

and 543,000 visited natural areas around their homes

(Florida Game and Fresh Water Fish Commission

1998). Urban forests may play an important role in

integrating recreational demands and conservation of

natural resources.

Now that we have discussed some values of

biodiversity, why should urban managers consider

biodiversity in the restoration of urban forests as

ecosystems? Urban and community forests have

been estimated to provide nationwide $3 billion a

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 8

year in social, ecological and economic benefits

(McPherson and Rowntree 1991). These benefits

include conservation of energy, pollution control,

and improvement of aesthetic quality of cities. By

managing and restoring urban forests for biodiversity,

such benefits could be greatly enhanced. For

example, by restoring ecosystems and their

associated natural processes, such as nutrient and

hydrological cycling, local communities could save

money, energy and resources. Restoring an urban

wetland to provide habitat for wildlife would also

contribute to recreational and economic

opportunities. Removal of invasive species from a

city's park, for instance, may bring back the natural

diversity and functioning of the ecosystem, which in

turn might improve its recreational and aesthetic

value for the local community.

Managing for biodiversity in urban areas will

require a more holistic approach than usually seen.

Urban forests are more than a collection of street

trees. Remnants of natural areas, waterways, parks,

backyards, right-of-ways and industrial parks both in

public and private properties are all part of the urban

forest ecosystem.

Can Biodiversity Be Protected In

Urban Forests?

Most human-made habitats, such as a

landscaped park, have lower biodiversity than natural

forests. However, urban environments usually

include a great diversity of habitats (such as water

retention ponds, industrial parks, railway

rights-of-way, greenways, and others) which may

support some wildlife and plant species. In some

cases, urban habitats may even play a significant role

in the conservation of 'rare' or 'threatened' species.

For example:

1. Rare prairie plant species in the Midwestern US

are found alongside railroads and highways. In

such areas these species are protected from the

agricultural activities that destroyed much of the

original prairie habitat (Ahern and Boughton

1994).

2. Of the 144 threatened and endangered wildlife

species of Illinois, 14% (20 species) have been

recorded in recent times in Cook county, the

most urbanized county of the Chicago

Metropolitan area (Friederici 1997).

How Is Biodiversity Reduced In

Urban Areas?

The ultimate threat to global biodiversity is an

increasing human population and the consequent

increased use and development of the world's

remaining natural ecosystems. The largest threat to

biodiversity in urban areas is the reduction and

alteration of the total area of natural ecosystems

available to native animal and plant species (Figure

10). Ecosystem destruction, degradation and

fragmentation may significantly reduce biodiversity.

Figure 10.1

Ecosystem destruction

Frequently, urban natural areas are completely

eliminated during residential and/or commercial

development. Usually, after construction exotic

trees, shrubs and lawns are established. Additional

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 9

Figure 10.2

Figure 10.3

Figure 10.4

Figure 10. Biodiversity is lost by ecosystem destruction

(10.1), fragmentation (10.2) and degradation. Figure 10.3

illustrates a degraded longleaf pine ecosystem that has

been invaded by exotic species whereas figure 10.4

illustrates a healthy longleaf pine ecosystem. The diversity

of the longleaf pine ecosystem is associated with its

herbaceous layer and a relatively open canopy.

amounts of fertilizers and irrigation, frequent

mowing and mulch are required for such intensively

managed areas.

If instead natural areas are preserved and

incorporated during development, biodiversity could

be maintained. Natural areas have much lower

maintenance requirements when compared to

traditional landscaping. Additionally, aesthetically

pleasing environments, such as natural urban

remnants, increase the economic value of residential

and commercial areas.

Ecosystem degradation

Ecosystem degradation may not be easily

noticed in the short-term and is difficult to detect and

harder to quantify. Degradation is of greater

long-term concern, since its effects are cumulative

and may build up only very slowly. Degradation

deteriorates and disrupts ecosystem processes. Some

examples of causal degrading agents are pesticides,

chronic air pollution and invasive species. Erosion,

or removal of the litter from a forested site would

also cause ecosystem degradation by interrupting

nutrient cycling.

Microorganisms in the soil (such as

invertebrates, fungi and bacteria) carry out critical

ecosystem functions (such as decomposition and

nitrogen fixation). Yet these organisms are so small

that they usually go unnoticed until the consequences

of their disruptions are too obvious to neglect.

In metropolitan centers, for instance, air

pollutants slowly accumulate in urban forest soils

over time. The gradual accumulation of

hydrocarbons in a New York urban forest, for

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 10

example, formed a hydrophobic soil layer, which in

turn, has decreased the population and activity of soil

microbes and invertebrates. This hydrophobic layer,

coupled with trampling and high concentrations of

heavy metals in urban soils, have also reduced the

rates of microbial processes, affecting the nitrogen

cycle in these forests (White and Mc Donnell

1988).

Ecosystem fragmentation

Landscapes become fragmented when natural

ecosystems are broken up into remnants of

vegetation that are isolated from each other (Figure

11). Therefore, fragmentation results in a landscape

that consists of remnant areas of native vegetation

surrounded by other land uses. At a larger scale the

landscape is composed of cities, farms, rivers, rural

areas and natural areas (Figure 12). In the urban

area the landscape might include strips of street trees,

backyards, schoolyards, shopping centers, creeks,

rivers, parks, landfills, industrial parks and fragments

of natural areas (Figure 13).

Figure 11. In urban areas, ecosystems that used to be

continuous are now fragmented in the landscape.

Figure 12.1 Photo by University of Florida, Map and

Imagery Library.

Figure 12.2

Figure 12. At a larger scale, the landscape is composed

of cities (12.1), farms, rivers, rural areas, natural areas and

fragments of natural areas (12.2).

Ecosystems are Connected and

Inter-related

The landscape is a mosaic of several different

ecosystems. It is important to recognize that natural

ecosystems are connected and inter-related.

Fragmentation of natural ecosystems will affect

ecosystem processes, plants, and wildlife. Turtles, for

example, live in water but need upland ecosystems to

lay their eggs. If we fragment upland ecosystems, by

either constructing a road between the ecosystems or

putting a fence around the upland, turtles will be

prevented from reproducing (Figure 14).

This example shows that we need integrated

management and restoration efforts, where

ecosystems are allowed to interact with each other.

Roads, fences or other human-made boundaries may

limit the flow of nutrients and water and the

movement of plants and animals between ecosystems.

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 11

Figure 13.1

Figure 13.2

Figure 13.3 Photo by Paul West, Seattle Department of

Parks and Recreation

Figure 13. In urban areas, the landscape is composed of

street trees (13.1), backyards, shopping centers (13.2),

parks, industrial parks and fragments of natural areas

(13.3).

Figure 14. This yellow bellied turtle (Trachemys scripta)

was stranded by a road while trying to move to an upland

ecosystem to lay eggs. This usually happens when the

interconnectedness of ecosystems is not taken into

account. Photo by Joseph Schafer

What happens to ecosystem

fragments?

Let's take a closer look at an ecosystem that has

been fragmented and isolated. Usually, conditions in

the surrounding landscape are different from

conditions in the ecosystem fragment. As a result, an

edge is formed between the landscape and the

ecosystem fragment. Every ecosystem has an edge,

but the amount of edge in urban ecosystem fragments

increases tremendously as a result of external factors

in the landscape. As the edge increases, the size of

the interior core is reduced.

The core area of an ecosystem fragment is the

undisturbed interior area of that ecosystem. In this

core area we usually have:

• functional ecological processes,

• a greater diversity of native species,

• a diversified structure with multilayered

vegetation (trees, shrubs, herbaceous and ground

cover plants), logs and snags,

• a greater diversity of wildlife with

area-sensitive birds, mammals, and other

animals, and

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 12

• an undisturbed microclimate.

Several external factors from the landscape can

affect ecosystem fragments (Figure 15). Along the

edge of the ecosystem fragment there is increased

solar radiation. Since there is more light available,

species that grow better in full sun will become

established closer to the forest edge while shade

tolerant species will be restricted to the interior core

(Saunders et al. 1991). Invasive species will also be

favored in edges and more disturbed areas.

Figure 15. External factors from the landscape affect

ecosystem fragments. The greater these external

influences, the greater the edge and smaller the core area.

Trees at the edge will also be more susceptible

to wind, air pollution and increased temperatures,

resulting in a drier microclimate (Saunders et al.

1991). In turn, nutrient cycling may be affected

because the heating of the soil may affect

microorganisms, litter decomposition, and soil

moisture retention.

Therefore, fragmentation alters the structure,

composition and function of ecosystems. A principle

to remember is that the more you alter the structure,

composition and function of ecosystems, the greater

the energy needed to restore the ecosystem back to

its original condition.

One example is Forest Park, a 5,000-acre urban

park in Portland, Oregon. This park is an ecosystem

fragment that has been greatly impacted by the

surrounding land uses. The neighboring

communities landscape their yards with English ivy

(Hedera helix), an invasive and aggressive species.

By bird dispersal and vegetative growth, English ivy

has spread and invaded this forest (Figure 16).

English ivy alters the structure of the forest (by

impeding the growth and development of native

plants), its composition (now there is only English

ivy underneath the canopy) and, consequently, this

ecosystem's functioning (alteration of nutrient

cycling, since decomposition of organic matter may

be affected). The amount of energy required to

restore this ecosystem is tremendous. It is an

ongoing effort, but as a result, native species are

regenerating and biodiversity is slowly coming back

to Forest Park.

Figure 16. These high school students are removing

English ivy, an invasive species that completely took over

Forest Park, an urban park in Portland, Oregon. Photo by

Mary Duryea

How Can Buffer Zones Help?

Buffer zones are semi-natural areas located

around areas of higher natural values, such as core

areas. A buffer zone around an ecosystem fragment

will minimize external influences and help maintain

the ecological integrity of the ecosystem's core area.

Establishment of buffer zones around natural and

semi-natural areas permits integration of human land

uses while still managing for biodiversity (Figure

17).

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 13

Figure 17. Buffer zones in urban settings can minimize

external influences of the surrounding landscape and

maintain the ecological integrity of urban ecosystem

fragments.

How does fragmentation affect

biodiversity?

Fragmented ecosystems are isolated and in urban

areas the distance between fragments may be large.

This, coupled with the increase in edge area and

reduction of the core area, will decrease flow of

genes and seed dispersal. Animals and plants that

used to be in the whole area are now restricted to

smaller patches.

Connected ecosystems or unfragmented

landscapes will have a greater diversity of native

species (Figure 18), due to their larger core area, a

lower edge:core area ratio and less isolation

(compared to smaller fragments).

Figure 18. The greater the area, the greater the number

of species in the ecosystem (adapted from MacArthur and

Wilson 1967).

Let's examine the consequences of

fragmentation on bird populations. Area sensitive

birds, such as flycatchers, vireos and warblers, will

be reduced with fragmentation and reduction in core

area. Area sensitive birds are those that need a large

undisturbed area and hence would only live in the

interior core area of a large fragment (Adams and

Dove 1989) (Figure 19.1). Habitat generalist birds

can be quite common in more urbanized areas and

may thrive in many different conditions. Cardinals,

jays, house wrens, and catbirds are examples of

habitat generalist birds (Figure 19.2).

If we want to enhance the diversity and the

presence of area sensitive birds in urban areas, we

need to restore and connect core areas of ecosystems

(for more information on wildlife, see Chapter

8-Wildlife).

Figure 19.1 Photo by Thomas G. Barnes

How Can We Connect Fragmented

Ecosystems In The Urban

Landscape?

The search for solutions to the problems of

ecosystem loss, degradation and fragmentation has

led to a growing number of new projects and

solutions. Most projects are based on ecologically

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 14

Figure 19.2 Photo by Thomas G. Barnes

Figure 19. Area sensitive birds, such as certain types of

owls (19.1) may have their diversity reduced with

fragmentation and a reduction in core area. However,

habitat generalist birds, such as common sparrows (19.2)

may be favored in a patchy environment.

sound principles. Basically, we attempt to connect

fragmented ecosystems in the urban landscape and

manage the landscape as a whole. By doing so, the

distance between ecosystems fragments will be

shortened, improving connectivity of isolated

fragments.

Connectivity is essentially the opposite of

fragmentation. Instead of breaking landscapes into

pieces we are seeking ways to restore broken

connections between fragmented ecosystems (Figure

20).

Figure 20.1

Figure 20.2

Figure 20. In Figure 20.1, patches A and B used to be part

of the same contiguous ecosystem. A corridor may

provide linkage between these ecosystem fragments.

Riparian coridors (20.2) are landscape linkages that may

connect several ecosystem fragments in the urban-rural

interface.

Effective connectivity is measured by the

potential for movement and flow of genes, that is,

movement and migration of animals (especially

birds) and dispersal of plants. Many factors

determine the effectiveness of connectivity, and it

varies depending on the ecosystem of interest.

Usually, effective connectivity will depend on:

• presence of barriers (e.g., fences which would

limit migration),

• distance between ecosystem fragments,

• amount of edge in the landscape linkage,

• nature of the surrounding landscape, and

• species which will benefit from promoted

connectivity (e.g., whether a bird,a mole, a

plant).

Connectivity can be promoted by using

corridors, greenways, and stepping stones.

Corridors

Corridors are strips of natural vegetation linking

ecosystem fragments. They can be defined as "any

area of habitat through which an animal or plant

propagule has a high probability of moving" (Noss

1991). Preserves or fragmented ecosystems with

high biodiversity level or rare species may be linked

by corridors (Figure 21).

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 15

Figure 21. This corridor may be serving as linkage for

birds between fragmented ecosystems. Photo by Henry

Gholz

Whether corridors will provide all or none of the

benefits listed in Table 1, will depend on several

factors. For instance, a corridor that has a high

proportion of edges compared to the interior forest

may facilitate spread of pests, diseases and

catastrophic fires or increase exposure of wildlife to

predators and domestic animals.

Table 1. Benefits and disadvantages of ecological

corridors.

BENEFITS DISADVANTAGES

enhance biotic movement

(because they permit flow

of genes)

spread of diseases

provide extra foraging

areas for species that

require more resources

than those available in a

single patch

increased predation

provide wildlife plant

habitat

Groups of corridors can be combined to form

corridor networks. By adding several corridors and

integrating them with buffer zones and natural

preserves, connectivity may be increased (Figure 22).

Figure 22. The proposed network of natural areas, buffer

zones and corridors forms a bigger regional network of

ecosystems for the state of Florida. This corridor network

connects two important waterways, Ockefenokee (North

Florida) and Everglades (South Florida), which have been

disconnected for decades.

Many restoration projects in cities begin with

river connections. Why are rivers and creeks

considered good linkage corridors? First, because

riparian ecosystems are considered to be one of the

richest habitat types, with alluvial soils, abundant

insects and plant species. They constitute one of the

most biologically productive and diversified habitat

types with complex and multilayered vegetation (see

Chapter 6 - The Hydrologic Cycle). Second, rivers

and creeks are natural corridors which pass through

many ecosystems, so the linkages between these

ecosystems already exist.

Greenways

Greenways are a type of corridor designed to

connect open spaces for ecological, cultural and

recreational purposes. There are a wide variety of

greenway projects around the country. We can find

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 16

greenways projects that are managed as corridors

between natural areas (with an ecological objective)

and others that are for purely recreational purposes.

Greenways range from narrow urban trails to

winding river corridors to very wide, landscape level

linkages.

It is important to define the goals of greenways.

In some instances, an urban greenway restricted to a

very narrow width, creating a beautiful space for

recreation, may be the primary goal (Figure 23).

However, relatively few greenways have been

designed with detailed consideration of ecological

functions (Smith and Hellmund 1993). Nonetheless,

a greenway's ecological function should be

considered and promoted whenever possible. An

example is the Rio Grande Valley State Park in New

Mexico. This park is a heavily used urban recreation

area located only 2 to 3 miles from downtown

Albuquerque, NM. The park contains extensive

riparian forests of native cottonwood (Populus

deltoides) and black willow (Salix nigra). These

forests contrast with the typical arid Southwest areas

surrounding them and for this reason host a high

diversity of wildlife and migratory birds.

Figure 23.1 Photo courtesy of Rio Grande Valley State

Park

Figure 23.2

Figure 23. Some greenways, such as the Rio Grande

Valley State Park in New Mexico (23.1), provide better

ecological function than this bicycle trail (23.2) in Florida.

Rio Grande Valley is a heavily used urban park that also

provides connectivity for wildlife and ecosystems.

Although activities like hiking, horseback

riding, picnicking, and nature walks are encouraged,

the Rio Grande Valley State Park gives high priority

to recreational trail design in order to protect

sensitive and unique habitats. Degraded areas have

been restored with native trees and shrubs, following

removal of saltcedar (Tamarix spp.), an invasive

species. Connectivity between high quality areas for

wildlife movement also have high priority. This

greenway effort seeks to restore natural species and

ecosystems processes, but also recognizes the need to

make resources available and enjoyable for people.

Stepping Stones

As mentioned before, viewing the landscape

holistically, instead of focusing on each separate area

in isolation, should be the objective of urban

managers. Even where it is not possible to connect

ecosystems through corridors, stepping stones can be

provided. Stepping stones (Franklin 1993) are

smaller habitats that permit some plants and animals

to move across the landscape from one ecosystem

fragment to the other (Figure 24). Some interior

species, such as many native birds, may not find

them useful, but for some other species, such as small

mammals and reptiles, the connectivity enhances

habitat.

The minimum ideal size for ecosystems to

remain fully functional is often unknown. However,

some scientists theorize that an optimum landscape

has large patches of natural vegetation supplemented

with small patches scattered as stepping stones

throughout the landscape (Franklin 1993, Noss 1991,

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 17

Figure 24. Stepping stones or small patches of

ecosystems may help some species move from one larger

ecosystem fragment (A) to another (B).

Adams 1994). In summary, stepping stones provide

habitat for species that will live in small areas and

help the flow of genes so birds and some plants will

be able to move across the landscape.

How Can We Restore Biodiversity In

Urban Areas?

There are numerous ways to enhance

biodiversity in parks, neighborhoods, abandoned

areas, backyards, industrial zones and other urban

forest restoration projects, including:

• leaving stumps, leaves, snags and logs on-site

to enhance the ecosystem's natural structure,

maintain the nutrient cycle, and provide habitat

for wildlife and other organisms,

• planting native species in combinations that

mimic nearby ecosystems,

• controlling invasive plants and animals which

may eliminate native species,

• enhancing the ecosystem's structural diversity,

and

• creating multi-age ecosystems (forests) in

several stages of ecological succession typical of

that ecosystem (see Chapter 4 - Plant

Succession and Disturbances).

In these urban forest restoration projects, it is

essential to maintain and/or restore the ecosystem's

ecological processes, such as:

natural disturbances: such as fires and natural

hydroperiods (for instance, re-instating flooding

in drained wetlands),

ecological succession: understand ecological

succession in nearby similar ecosystems and

consider establishing these successional stages

(for more information see Chapter 4 - Plant

Succession and Disturbances),

nutrient cycle: promote and educate about the

need for retaining leaves, twigs, branches and

logs on site to store and cycle nutrients (see

Chapter 2 - Basic Ecological Principles), and

hydrological cycle: find ways to aid the

hydrological cycle. Examples include leaving

natural mulched areas for better water

infiltration and maintaining vegetative cover to

prevent water erosion (see Chapter 6 -

Hydrologic Cycle).

Examples of Restoration Projects

There are many projects in cities and urban areas

that restore urban forests as whole ecosystem(s).

Biodiversity is often an important part of these

restoration projects, either at a small or large scale.

Reintroducing Fire in Gainesville, FL

Natural fire regimes are important ecological

processes that should be reintroduced in fire-adapted

ecosystems, including urban forest ecosystems.

For example, the longleaf pine ecosystem, a

natural forest type of the Southern US, is adapted to

periodic and light fires. Fires keep adjacent

hardwood species from invading longleaf pine

forests (Figure 25.1). In the process, these fires

maintain an extremely diverse flora in the ground

layer (Figure 25.2). There are more than 100

herbaceous species in sites no larger than an acre and

at least 190 rare and endemic species associated with

this ecosystem (Hardin and White 1998). Fires are

essential to maintain this ecosystem's natural

structure, that is, an open canopy of longleaf pines

and the diverse ground layer. If fires are suppressed,

this unique flora is largely lost.

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 18

Figure 25.1

Figure 25.2

Figure 25. Frequent but low intensity fires keep adjacent

hardwood species from invading longleaf pine ecosystems

(25.1), and are essential to maintain these forests' natural

structure and ground layer biodiversity (25.2).

Fires have been reintroduced in remnants of

longleaf pine ecosystems in urban areas. An example

is a subdividion in Gainesville, FL, that contains

patches of a longleaf pine ecosystem interwoven with

houses, golf courses and streets. Periodic prescribed

fire is applied to these patches of longleaf pine,

maintaining its open canopy and rich herbaceous

species. Education plays a key role in such innovative

pratices in urban centers (Figure 26).

Figure 26.1

Figure 26.2

Northeast Anne Greenbelt Forest

Restoration in Seattle, WA

Downtown Seattle has a 35-acre restoration

project developed by the Seattle Department of Parks

and Recreation (SDPR), University of Washington

and the local community. This project is part of a

greater effort to apply integrated landscape

management practices in parks and other areas in the

Seattle region (Figure 27).

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 19

Figure 26.3

Figure 26. This subdivision in Gainesville, FL has patches

of a longleaf pine ecosystem (26.1) interwoven with

houses, golf courses and streets (26.2). Periodic

prescribed fire is applied to these patches. Education

plays a key role in such innovative practices in urban areas

(26.3).

Figure 27. The Northeast Anne Greenbelt Forest

Restoration is a neighborhood restoration project in

Seattle, WA (map at left). Other similar small scale

projects are funded and coordinated by the Seattle

Department of Parks and Recreation.

The site was heavily invaded by exotic invasive

species (English Ivy , bindweed, Himalayan

blackberry, and Scotch broom), ornamental plants

and weeds, and was also a dumping ground for trash.

Additional problems were soil erosion and lack of

wildlife.

The partners worked together and developed a

plan to:

• remove the exotic vegetation,

• plant varying native species to provide food

and cover for wildlife and to enhance structural

diversity,

• create logs and snags to provide habitat for

invertebrates, woodpeckers, and decomposers,

and

• plant trees with deep roots and understory

vegetation to help stabilize the soil and reduce

erosion.

Today, the area has been cleared of exotics,

erosion has been stabilized and an environmental

center has been established, where the local

community promotes educational and recreational

activities.

Chicago Wilderness in Chicago, IL

The Chicago Wilderness is a combined effort of

60 partnering organizations, including landowners,

local, regional and federal agencies, universities and

conservation agencies. The Chicago Wilderness'

primary goal is to restore ecological processes that

maintain biodiversity. Their work is to improve the

region's biodiversity at all levels: genetic, species

and ecosystem diversity throughout the landscape.

To meet this goal they have several objectives:

• to document the region's ecosystems,

• to help restore natural communities on public

and private lands,

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 20

• to prevent further loss of critical ecosystems

and, at the same time, promote carefully planned

development,

• to promote education, outreach and volunteer

opportunities, and

• to define restoration strategies (including

removal of aggressive invasive species, thinning

of native trees to promote growth of savannas

and woodlands species, use of prescribed fire

and planting of native species).

To date, there are over 109 Chicago Wilderness

collaborative projects ranging from biodiversity

initatives to prairie and savanna restoration projects

with prescribed burning to backyard biodiversity

initiatives to restoration of threatened and

endangered species (Figure 28).

Figure 28. Outreach materials utilized by Chicago

Wilderness educate citizens about the region's biodiversity

and strategies for restoration.

Monitoring Success

Monitoring is a crucial part of every ecosystem

restoration project. Monitoring provides the

opportunity to gather information about how

ecosystems in urban areas work and how ecosystems

and people interact over time. It is also a critical

activity for reevaluating the success or failure of

projects so that we can apply this accumulated

knowledge and experience to future projects.

Ecosystems are complex and inter-related and

even the best studied and planned projects might

have unexpected results. One example of a learning

experience is a salt marsh, 8 km south of downtown

San Diego, CA. The restored ecosystem was

supposed to provide habitat for an endangered bird,

the light-footed clapper rail (Rallus longirostris

Levipes) (Figure 29). Cordgrass species (Spartina

spp.) were transplanted from nearby wetlands to

provide nesting sites for the bird. However, the plant

did not grow to 90 cm, the bird's preferred height.

Researchers working on the project thought the

problem was due to the marsh's sandy, nutrient-poor

soil, so they added nitrogen fertilizers. But the

fertilizer favored another plant, pickleweed, which

outgrew the desired grass (Malakoff 1998).

Researchers are still trying to determine the best

methods for restoring this ecosystem.

Figure 29. Since ecosystems are complex and

inter-related, careful planning and monitoring are essential

elements of restoration projects. The example of this salt

marsh and the light-footed clapper rails reminds us that

there are no easy recipes. Photo by David Sarkozi

Conclusions

Urban forest ecosystems present many

opportunities for restoring biodiversity, whether in a

backyard, neighborhood, park or natural area. It is

essential to know and understand the natural

ecosystems in these areas in terms of vegetation,

structural diversity, wildlife, natural disturbance

regimes and the nature of their ecological processes.

When managing ecosystems for biodiversity, we

should pay attention to ecosystem structure and its

Chapter 3: Biodiversity and the Restoration of the Urban Forest Ecosystem 21

functioning. Ecological processes, such as nutrient

cycling, hydrological cycling, and ecological

succession should be reinstated in the urban forest

ecosystem as a comprehensive strategy for

biodiversity conservation.

Corridors, buffer zones, greenways, and

stepping stones are all ways in which urban forests

can be managed as ecosystems. While large scale

projects may help reestablish connectivity and

maintain important ecological processes, small scale

projects, such as removing invasive species or

restoring native species in a small city park, also

contribute.

However, management of the landscape as a

whole can only be accomplished if we take an

interdisciplinary and integrated approach toward

urban forests. This requires a combined and joint

effort of local, state and federal governments, as well

as private, public and grass-root initiatives.

Education plays a critical role in generating informed

citizens who are essential partners in the

establishment of restoration projects in cities.

Suggested Readings

Dunster, J. A. 1998. The role of arborists in

providing wildlife habitat and landscape linkages

throughout the urban forest. Journal of

Arboriculture, 24(3): 160-167.

Argent, R. M. 1992. Ecological succession as a

criterion for the selection of urban trees.

Dissertation, Texas A&M University. 80p.

Sun, W. Q. 1992. Quantifying species diversity

of streetside trees in our cities. Journal of

Arboriculture, 18(2): 91-93.

Cited Literature

Adams, L. and L. E. Dove. 1989. Wildlife

reserves and corridors in the urban environment: A

guide to ecological landscape planning and resource

conservation. National Institute for Urban Wildlife,

Columbia, MD. 87p.

Adams, L. W. 1994. Urban wildlife habitats: A

landscape perspective. University of Minnesota

Press, Minneapolis, MN. 186p.

Ahern, J. and J. Boughton. 1994. Wildflower

meadows as suitable landscapes. In: Platt, R.H.,

Rowntree, R. A. and Muick, P. C. (eds), The

ecological city: Preserving and restoring urban

biodiversity. pp 172-187, University of

Massachusetts Press, Amherst.

Costanza, R., R. d'Arge, R. de Groot, Farber, M.

Grasso, B. Hannon, K. Limburg, S. Naeem, R. V.

O'Neill, J. Paruelo, R. G. Raskin, P. Sutton and M.

van den Belt. 1997. The value of the world's

ecosystem services and natural capital. Nature,

387(6630): 253-258.

Florida Game and Fresh Water Fish

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Chapter 4: Plant Succession and Disturbances in the

Urban Forest Ecosystem1

Eliana Kämpf Binelli, Henry L. Gholz, and Mary L. Duryea2

1. This is Chapter 4 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Eliana Kämpf Binelli, Extension Forester, Henry L. Gholz, Professor, and Mary L. Duryea, Professor and Extension Forester, School of Forest Resources

and Conservation, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Ecosystems are dynamic. Disturbances lead to

changes in ecosystems, collectively called

succession. Disturbances can be natural and/or

anthropogenic (human-caused). Natural

disturbances, such as wildfire, play an important role

in forest succession. Knowledge of natural

disturbance regimes is important to maintaining

biodiversity. In forest succession, species

composition, ecosystem structure and ecosystem

functioning all change gradually over time. In urban

areas, the alterations of natural disturbance regimes,

along with the introduction of invasive species have

altered natural succession. Natural disturbances vary

in spatial scale (from small to large areas) and

temporal scale (from hours to eons). Variation in the

temporal and spatial scales of disturbances leads to

ecosystems spread over the landscape that are in

different successional stages. This landscape

diversity meets the needs of a variety of wildlife

species. In order to restore more natural successional

regimes, we have to learn about ecosystems: their

natural disturbance regimes, their expected stages of

succession, and how they fit into the overall

landscape. Small scale urban forestry projects should

incorporate the concepts of succession, while

eliminating invasive species and re-introducing

natural disturbances regimes. Large scale projects

can also adopt these strategies, but have the

additional opportunity to manage for several stages

of succession across the landscape and to restore

missing stages of succession.

Change

A common misperception is that nature is in an

unchanging balance. However, natural scientists have

found strong evidence against this idea and we now

know that change is one of the most fundamental

characteristics of natural ecosystems.

Since trees generally live much longer than

humans, the forests they are in were also perceived

as unchanging. But, in fact, forests are highly

dynamic. In many forests, wildfires, floods,

windstorms or insect infestations produce major, but

infrequent changes. In other forests, change is more

subtle: single trees die and are replaced while most

trees remain alive. However, since individual trees

can live a long time, it is difficult to see or measure

changes in forests over short periods of time.

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 2

There are two related aspects of change over

time in forests: disturbances and succession.

Disturbances lead to subsequent changes in

ecosystems, which are collectively called succession.

This chapter discusses the dynamic nature of

forest ecosystems and why it is important to

understand disturbances and succession in order to

manage and restore urban forest ecosystems

successfully.

Disturbances

What are disturbances?

Disturbances are any event, either natural or

human-induced (anthropogenic), that changes the

existing condition of an ecosystem. Disturbances in

forest ecosystems affect resource levels, such as soil

organic matter, water and nutrient availability, and

interception of solar radiation. Changes in resource

levels, in turn, affect plants and animals over time,

leading to succession.

Disturbances occur in all ecosystems. We often

think disturbances result only from human activity.

However, the definition of disturbance should not

carry a connotation of negative human impact;

naturally occurring disturbances are part of every

ecosystem on earth.

What types of disturbances affect forests?

All forests are subjected to both natural and

anthropogenic disturbances. Examples of naturally

occurring disturbances include wildfires, winds

(hurricanes, tornadoes and windstorms), insect and

disease epidemics, landslides, ice storms, floods and

droughts (Figure 1).

Figure 1.1 Photo by Larry Korhnak

Figure 1.2 Photo by Larry Korhnak

Figure 1. Historical fires (1.1) and natural hydroperiods

(1.2) are examples of naturally occurring disturbances

which have been virtually eliminated from urban forest

ecosystems.

Examples of anthropogenic disturbances include

pollution, conversion of forests to nonforest areas,

timber harvesting, prevention of wildfires, global

warming, alteration of natural hydroperiods

(flooding), application of herbicides, introduction of

exotic species, litter raking, trampling and

compaction, fertilization and irrigation (Figure 2).

Figure 2.1 Photo by John Rieger, CA Department of

Transportation

The urban forest ecosystem is also subjected to

anthropogenic and natural disturbances. However,

natural disturbances, such as wildfires and normal

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 3

Figure 2.2 Photo by Larry Korhnak

Figure 2. Conversion of forests to development (2.1) and

raking of litter (2.2) are examples of anthropogenic

disturbances in urban forest ecosystems.

flooding periods, have been virtually eliminated from

urban forest ecosystems (Table 1).

Table 1. Types of disturbances that occur or have been

eliminated from urban forest ecosystems (UFE's)

TYPES OF DISTURBANCES THAT OCCUR

MOST OFTEN IN UFEs

• removal of topsoil and soil grading

• air and soil pollution

• litter raking

• introduction of invasive species

NATURAL DISTURBANCES THAT HAVE

BEEN ELIMINATED FROM UFEs

• natural fires

• normal periodic flooding

• nutrient cycle

The focus of this chapter will be on naturally

occurring disturbances and their importance to

ecosystems. Ideally, restoration should return a site to

a condition that includes a natural disturbance

regime, but it may also be aimed at minimizing those

anthropogenic disturbances that are considered

undesirable.

The Importance of Natural Disturbances:

Yellowstone and the Suppression of

Wildfires

Fire may be the most widespread natural

disturbance in the world's forest ecosystems. In fact,

many forest and wildlife species persist because of

periodic fire disturbance. However, the perspective

that all disturbances are abnormal led to the Smokey

the Bear syndrome where all forest fires were

perceived as bad.

A classical example of the consequences of fire

suppression is the 1988 catastrophic fire that swept

through Yellowstone National Park, killing much of

its vegetation. The natural cycle of fire disturbance in

the park had been interrupted for more than one

hundred years by intentional fire suppression. This

led to a dense invasion by shade-tolerant trees and

understory vegetation, and excessive accumulation of

litter and woody debris in the forest, which

eventually caused rampant, intense and impossible to

control wildfires (Figure 3).

Why are disturbances important?

Disturbances are the norm for forest ecosystems.

Completely undisturbed forests are extremely rare or

even nonexistent.

The role that natural disturbances play in forests

is one of renewal. Whether the disturbance is big or

small, mild or intense, it plays an important role in

determining a forest's succession (Figure 4).

Disturbances initiate succession in ecosystems by

killing some or all individuals (depending on its

intensity), as well as disrupting litter/detrital (dead

organic matter) pools.

Fires initiate succession by reducing the number

of plants on a site and creating openings in the

canopy and near the ground, allowing understory

plant species and tree seedlings to grow. For

example, in the longleaf pine ecosystem in the

southern U.S., frequent low intensity fires keep the

ground clear of underbrush. These fires kill many

saplings of trees and a few larger trees, while

allowing sufficient seedlings to become established

and maintaining an open tree stand of low density. In

the absence of fire, the forest eventually loses the

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 4

Figure 3. Suppression of natural cycles of fire disturbance

in the Yellowstone National Park caused fires of

destructive dimensions in 1988. Photo by Jeff Henry

Figure 4.1 Photo by Jeff Henry

Figure 4.2 Photo by Jeff Henry

Figure 4.3 Photo by Jeff Henry

Figure 4. Fires play an important role in forest renewal

and succession. Figures 4.1, 4.2, and 4.3 sequentially

show the regrowth of vegetation following the 1988

Yellowstone National Park catastrophic fires.

longleaf pine and is completely dominated by older

shade-tolerant trees.

Fires revitalize the soil by allowing some

nutrients that are bound in the leaf and branch litter

to be returned to the soil. Trees and branches that fall

in forest fires create habitat for ground-nesting birds,

reptiles and amphibians (Figure 5). Thus, fires can

provide conditions for a wide variety of plant and

animal species, and maintain biodiversity in forests.

Disturbances, such as fire, are therefore a major

diversifying force in forest ecosystems.

Figure 5.1 Photo by Larry Korhnak

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 5

Figure 5.2 Photo by Larry Korhnak

Figure 5. Fires (5.1) release nutrients that were bound in

the leaves, branches and organic matter and make them

available for plant uptake (5.2). Burned logs and snags

are also habitats for a variety of mammals, reptiles and

amphibians.

However, it is important to note that not all

disturbances renew and invigorate ecosystems. Some

disturbances are damaging and result in

destabilization of the ecosystem. One example of

such a disturbance is chronic pollution, which may

cause long-term cumulative impacts that may not be

easy or possible to reverse.

Disturbances and Biodiversity

Prairies, oak savannas, and long-leaf pine

ecosystems of the Southern U.S. are examples of

ecosystems that are dependent on frequent,

low-intensity ground fires. These fires have occurred

historically at intervals of 1 to 25 years. The life

histories of the dominant species in these

communities have been shaped evolutionarily by fire

(Platt et al. 1988). Without fire, these ecosystems

gradually change to other vegetation types (Figure

6). A knowledge of natural disturbance regimes is

essential for maintaining regional biodiversity.

Ecologists have evidence that species diversity

will be highest at some intermediate frequency or

intensity of disturbance (Connell 1978, Pickett and

White 1985). Frequent disturbance allows only

species that colonize rapidly to persist, whereas long

periods without disturbance may exclude desirable

dominant plant species from the ecosystem (Figure

7).

Land managers should realize that species in any

region have adapted, through evolution, to a

particular disturbance regime. If we radically alter

that regime, many species will be unable to cope with

the change and will be eliminated.

Figure 6.1

Figure 6.2

How often do disturbances occur?

The disturbance regime is a combination of how

often the forest is disturbed (frequency), how severe

the disturbance is (intensity), and how large the

affected area is (extent). In general, the frequency

and intensity of natural disturbances are inversely

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 6

Figure 6.3

Figure 6. Longleaf pine ecosystems are dependent on

frequent, low intensity ground fires. Fires maintain an open

canopy (6.1) and an extremely diverse flora in the ground

layer (6.2). In the absence of fires, other species, such as

vines and shrubs, are favored resulting in the loss of this

ecosystem's natural diversity (6.3).

Figure 7. The intermediate disturbance hypothesis

indicates that species diversity is highest at intermediate

frequencies or intensities of disturbance.

related. For example, volcanic eruptions or large

meteor impacts (high intensity) fortunately only

occur rarely (at a low frequency).

Some anthropogenic disturbances, such as

global climate change, occur only at a very low

intensity. However, these disturbances may be

directional and may cause large cumulative effects

over a long period of time. Because short-term

effects are small, they are very difficult to detect.

If a disturbance is very intense, ecosystems can

be totally destroyed, as when a forest is converted to

a parking lot. The more intense the disturbance, the

more difficult and costly it is to restore what was

there before. Severe erosion, for instance, may lead

to a degraded ecosystem that will never fully recover

to the prior condition without extremely costly

intervention, such as importing soil.

In urban areas the challenge is to determine the

appropriate natural disturbance regime to mimic

and/or reinstate.

Succession

What is succession?

The changes in an ecosystem that follow a

disturbance are collectively called succession.

Succession is a dynamic and continuous process,

often occurring gradually over time. Forest

succession is the change in species composition, age

and size, and ecosystem structure and function over

time.

Let's consider the development of an abandoned

farm field in the Piedmont of the Southeastern U.S.

over time to demonstrate succession (Figure 8). This

farm field is surrounded by pine-hardwood forests,

typical of this part of the country (8.1). During the

first year or two, annual forbs cover the field (8.2).

Plants such as goldenrod and asters follow the

second and third year (Perry 1994). In this early

stage of succession, if we walk in this field, we can

hear birds such as grasshopper sparrows and

meadowlarks (Meyers and Ewel, 1990).

Figure 8.1

The grass-forb stage would be gradually

replaced by a shrub-pine-seedling community that

will last perhaps 15 to 20 years (without further

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 7

Figure 8.2 Photo by Natural Area Teaching Laboratory at

University of Florida

Figure 8.3 Photo by Natural Area Teaching Laboratory at

University of Florida

Figure 8.4 Photo by USDA Forest Service

Figure 8. Sequence of successional stages in an

abandoned farm field in the southeastern U.S. over time.

During the first years (8.1) the area is colonized by a

mixture of pioneer species (8.2). This stage is gradually

replaced by a shrub-pine community (8.3). In about

150-200 years, without further disturbances, an

oak-hickory forest may replace the pine forest (8.4).

disturbances) (8.3). Birds such as the yellowthroat

and field sparrow will be common. Pine seedlings

continue to grow in the abundant sunlight and, from

about year 25 to year 100, a pine forest may dominate

the site, providing habitat for birds such as the pine

warbler (Meyers and Ewel 1990).

Pine seedlings do not grow in the shade of taller

pines, but shade-tolerant oaks and hickories do. In

about 150 to 200 years, in the absence of fire, an

oak-hickory forest may replace the pine stand (8.4).

Birds such as the red-eyed vireo will thrive in the

deciduous forest (Meyers and Ewel 1990). The

seedlings of oak and hickory, capable of growing in

the shade of the older trees, will thrive and thus

replace the older oaks and hickories that die of

disease, old age or other causes.

However, if fire does occur again, or the trees

are harvested, pine forests can be maintained in the

landscape for hundred of years. Natural disturbances

can keep an ecosystem in a certain successional stage

for long periods of time. This issue will be discussed

further in the section The Role of Disturbances in

Succession.

Why is succession important?

Urban trees are often managed as individuals

instead of as parts of ecosystems. Individual urban

trees and other vegetation may well provide many

benefits such as energy conservation, beauty,

recreation and climate amelioration. Yet, by

managing them as part of an ecosystem, additional

benefits can be achieved, such as increased animal

biodiversity, reduced storm-water runoff and erosion,

and significantly reduced maintenance costs.

Ecosystems that proceed through natural

succession may be managed with much less costly

intervention (Figure 9). Urbanization and its

associated activities have a profound impact on

natural succession, with the end result that little

natural succession occurs in most metropolitan areas.

For example, a widespread practice in urban forests

is to clean out the understory by raking leaves,

branches, seeds and seedlings on the forest floor.

Logs and snags are also often removed. Such a loss

of the understory, along with logs and snags may

have negative consequences for many wildlife

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 8

species dependent on these forest structures. In the

long term, such practices will lead to loss and

degradation of the forest itself, since nutrients are not

efficiently stored and recycled. As trees die, there are

no replacements, since the seed bank and seedlings

were removed, and natural succession is severed. As

a consequence, erosion increases and fertilizers and

soil amendments must be used to bring nutrients back

to the system.

Figure 9.1

Figure 9.2 Photo by Larry Korhnak

Figure 9.3 Photo by Larry Korhnak

Figure 9. Ecosystems that are able to follow natural

succession, such as naturally landscaped backyards (9.1),

may be managed without costly intervention. Such

backyards will require less mowing, irrigation, fertilizers,

herbicides and pesticides (9.2) when compared to

backyards that use lawns extensively with only a few

scattered trees (9.3).

Likewise, the extensive use of ornamental

invasive species and "weed-free" lawn areas have

similar impacts. Herbicides, fertilizers, pesticides,

irrigation, and frequent mowing and raking are often

required to maintain such areas, representing extra

maintenance costs for urban managers. On the other

hand, natural ecosystems that are able to follow

succession can be managed without these additional

costs (Figure 10).

To successfully manage urban forest

ecosystems, managers need to understand how living

and dead vegetation, wildlife and various

disturbances interact. The ecological and economic

advantages of maintaining and/or restoring natural

succession need to be identified and incorporated into

the management of the urban forest ecosystem.

Types of succession

There are two types of succession, primary and

secondary.

Primary succession

Primary succession occurs in environments that

lack organic matter and which have not yet been

altered in any way by living organisms. Primary

succession includes the development over time of

the original substrate into a soil, and occurs over

centuries or even eons.

The 1981 eruption of Mount Saint Helens in

Washington provided an example of primary

succession (Figure 11). This eruption wiped out

most or all traces of life in a substantial area to the

northeastern part of the mountain, leaving barren

areas of deep ash deposits (11.1). A set of organisms

adapted to survive and reproduce in these conditions

has since become established (11.2). Some plants

were able to extract nitrogen directly from the

atmosphere (nitrogen-fixing species) and most were

also dependent on the formation of fungal association

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 9

Figure 10.1 Photo by Linda Robinson Figure 10.2

Figure 10. Extensive use of ornamental invasive species

will affect succession. This English ivy (10.1), for example,

displaced and killed a native pine species. Control of

invasive species, whether mechanical or chemical, is a

costly and time consuming operation (10.2).

with the roots (mycorrhizae) for extracting nutrients

from the ash (Perry 1994).

Figure 11.1 Photo by Michael P. Doukas

Because of these characteristics, such organisms

began to modify the site by accumulating nutrients

and building up soil organic matter. As these

organisms modify the site further, they will

eventually be replaced by other organisms better

adapted to the new conditions. For example, plants

that required abundant light to grow will be replaced

by more shade tolerant species.

As trees become established, there may be

relatively long periods of this successional stage

(e.g., Douglas-fir forests), which may persist only

until the next eruption (11.3). In areas protected from

future eruptions, a relatively persistent ecosystem

may eventually occupy the site (e.g., Western

hemlock forest) (Perry 1994) (11.4).

Another example of primary succession occurs

on rock or subsoil surfaces exposed by landslides.

Primary succession can occur in urban forests where,

for example, surface soil and organic matter have

been completely removed from a site. In this case,

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 10

Figure 11.2 Photo by Lyn Topinka

Figure 11.3 Photo courtesy of R. Emetaz, U.S.

Department of Agriculture

Figure 11.4 Photo courtesy National Park Service

Figure 11. The eruption of Mt. Saint Helens is an example

of primary succession. It eliminated most traces of life in a

substantial area of the northeastern part of the mountain

(11.1). Less than a decade later, pioneer and early

successional plants have colonized the area (11.2).

Eventually, Douglas-fir forests will become established

(11.3) and, without further disturbance, over several

hundred years a Western hemlock forest may eventually

occupy the area (11.4).

primary succession can be hastened through the

addition of top soil.

Secondary succession

Secondary succession occurs in an environment

that has supported mature vegetation in the past, and

where, after the disturbance, the substrate (i.e., soil)

remains relatively intact.

Secondary succession also occurs in urban areas.

Suppose you decide to give up the fight with weeds

in your backyard and no longer mow your lawn. The

changes that take place will be typical of "old-field"

secondary succession. First, your backyard would be

colonized by a variety of plants, mostly annuals.

Within a few years, these plants would be joined by

perennials and smaller shrubs and the grass would

start to disappear. Later, a mix of taller shrubs and

tree species would seed in. Then, maybe 50 years

from now, you would have a successional forest in

your backyard.

Additional examples of secondary succession

include the changes in vegetation and ecosystem

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 11

characteristics in abandoned agricultural fields and

in forests after clear-cuts, windstorms or fires.

The Role of Disturbances in

Succession

Let's consider again the previous succession

example of an abandoned farm field in the

Southeastern U.S. (Figure 8). Natural disturbances

may occur at any time during the development of the

abandoned farm field into the pine or oak-hickory

forest. Natural disturbances can keep an ecosystem

in a certain successional stage for long periods of

time. Fire of any type, for example, may prevent

hardwood regeneration and maintain pine forests in

the landscape for hundred of years.

Natural disturbances vary in spatial scale (they

may occur in small, medium or large areas) and

temporal scale (they occur at different time periods).

For instance, individual trees or a group of trees may

die and fall, forming small gaps in the forest, while

wildfires may kill trees over thousands of acres

(Figure 12). Consequently, in many forested

ecosystems, disturbance leads to a condition where

local successional patches are continuously formed,

leading to a "shifting mosaic" across the landscape

(Bormann and Likens 1979).

Figure 12. In many forested ecosystems, disturbances

such as fires, promote areas with burned and unburned

vegetation. Small successional patches are formed.

Eventually, across broad stretches of forest, there will be

patches of vegetation in several successional stages. Paul

Schmalzer

Different wildlife species are adapted to

different successional stages (Figure 13). In

"old-field" succession, for instance, pine warblers

would be common to the pine forest successional

stage, while red-eyed vireos and wood thrushes

would be found in oak-hickory forests.

Some mature forests (such as old-growth forests

in the northwestern US) take many hundreds of years

to reach a late successional stage. Some species

associated with these forests, such as the northern

spotted owl (Strix occidentalis), may not survive if

only earlier stages of succession are present (Eckert

1974). It is a major challenge is to determine and

maintain an appropriate mix of successional stages

within a landscape.

Figure 13. These bird species require different

successional stages as habitats. Adapted from Smith 1990

Different Stages of Succession Provide

Habitat for Different Wildlife Species

The American kestrel (Falco sparverius) needs

several stages of succession to meet its requirements

for food and cover (Figure 14). This bird feeds

primarily on insects and small mammals, which are

present in early successional stages that contain

annual and perennial forbs and grasses. However, it

also requires intermediate and late stages of

succession, such as mixed woodlands (shrubs and

trees) and more mature forests, for nesting (Neilson

and Benson 1991).

American kestrels are widely distributed in

North America. However, the number of

southeastern American kestrels (Falco sparverius

paulus) has decreased over 80% in the last 50 years

(Wood et al. 1990). The main cause for the decline

has been the destruction of longleaf pine ecosystems,

the preferred nesting habitat for this species.

Other animals are also highly dependent on a

certain stage of successional development. For

instance, the structure and stage of development of

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 12

Figure 14. American kestrels are widely distributed in

North America. They feed on insects and small mammals,

which are present in early stages of succession (grasses

and forbs). However, the American kestrel also requires

intermediate and late stages of succession, such as mixed

woodlands (shrubs and trees) for nesting. Photo by David

Sarkosi

scrub vegetation has a profound effect on wildlife

habitat availability in Florida (Figure 15).

Figure 15.1 Photo by Wayne Peterson

Figure 15.2 Photo by Anne Birch

Figure 15.3 Photo by Paul Schmalzer

Figure 15. The Florida scrub jay (15.1) is endemic to the

scrub ecosystem in the southeastern U.S. It requires a low

shrub layer, bare ground and a few scattered trees (15.2)

avoiding canopied areas. The scrub ecosystem is

maintained by periodic fires (15.3).

The Florida scrub jay (Aphelocoma coerulescens

coerulescens) (15.1), an endemic species in Central

Florida, is restricted to the pine/oak scrub

ecosystems (15.2). This bird requires a low shrub

layer, bare ground and a few scattered trees, avoiding

heavily canopied areas. The scrub ecosystem is

maintained by periodic fires (15.3). In this case, if

fire is excluded for long periods of time, a sand pine

canopy develops and scrub jays abandon the site

(Woolfenden and Fitzpatrick 1984) (15.4).

Succession in More Detail

Following a severe disturbance, sites are initially

dominated by early successional plants, called

pioneer species. Pioneers are usually prolific seeders

(or sprouters), fast-growing and short-lived species,

and generally intolerant of shade.

Pioneer species are then followed by shrubs and

early successional trees which, in turn, are eventually

replaced by late-successional species. Later

successional species are generally shade tolerant and

may grow much more slowly. Their seedlings will

survive and grow beneath an established canopy, and

eventually they will overtop the shrubs and replace

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 13

early successional trees (Figure 16). Therefore,

during succession, pioneers create conditions

conducive to species that will form an intermediate

or transitional community. This, in turn, creates

conditions favorable to species that form

late-successional communities.

Figure 16. Following a disturbance, sites are initially

dominated by early successional plants, called pioneer

species (grasses and herbs). Pioneers are then followed

by other shrubs and early successional trees which, in

turn, are eventually replaced by late-successional species.

The composition and relative dominance of

various plant species changes over time because, in

part, they have different life strategies (some plants

grow best in full sun while others require shade, for

example). Succession can be viewed as a biological

race to make optimum use of available site

resources, such as light, soil, nutrients and water.

The pattern of vegetation found in a landscape

results from the interactions among soil types, water

availability, life history strategies of plants and

natural disturbances, all of which vary at different

spatial and temporal scales (Turner 1987). These

interactions will result, over time, in patches of

vegetation in different stages of succession across

the landscape. Therefore, the dynamics of forests

cannot be grasped by looking at only a single site, and

individual forests' stands should not be managed in

isolation from others in the landscape in which they

are embedded (Perry 1994).

Phases of secondary succession

Although succession is a continuous process, it

is useful to identify four main phases in secondary

succession (after Bormann and Likens 1979):

Figure 17. Bormann and Likens (1979) proposed four

phases of secondary succession: reorganization,

aggradation, transition and steady state (or climax).

1. Reorganization phase

This is the period immediately following a

disturbance, when pioneer species are establishing.

There is usually a high availability of resources

(light, nutrients and water) and plant competition is

low. Because the quantity of leaves per unit of

ground area is not yet high, loss of water from leaves

is low and runoff of water is high. Consequently,

there is also a high potential for nutrient losses from

the soil and erosion, since nutrient uptake by plants is

low and water runoff high.

2. Aggradation phase

During this phase, plants rapidly accumulate

biomass, especially in woody stems, while detritus

also builds up on the ground. Restoration ecologists

usually try to shorten the reorganization phase, and

consequently hasten the aggradation phase, by

planting trees and shrubs that will grow quickly,

covering the site with leaf surface area.

3. Transition phase

This phase is characterized by a first wave of

tree mortality, caused by increased competition

among the pioneer trees, accumulation of snags and

logs, and the establishment of shade tolerant species

in the understory.

4. Steady State (or Climax) phase

The transition phase ends at a stage characterized

by large accumulations of both living biomass and

coarse woody debris (snags and logs). Forests that

reach this phase usually have high structural

diversity. Tree growth slows down in this phase,

accompanied by increased tree mortality; any growth

that does occur is offset by mortality.

The period of time that different ecosystems stay

in each of these successional phases depends on

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 14

environmental conditions and the nature of

disturbance regimes. For example, the reorganization

phase usually passes quickly but after severe

disturbances or in harsh climates it can be greatly

prolonged. Likewise, the aggradation phase varies

widely from one forest type to another, and is much

more rapid in favorable environments and where

denser, more even-aged stands develop.

Changes in ecosystem function, structure

and composition through succession

In addition to species composition, the structure

and functioning of ecosystems also change during

succession (Table 2). For example, most forest

ecosystems only have abundant logs and snags

(structure) later during succession or after a

disturbance, such as a severe windstorm. In other

ecosystems, a low intensity, frequent disturbance

such as ground fire, burns low vegetation and some

trees, releasing nutrients and competition, which

changes both the pattern of nutrient cycling

(function) and the vertical layering of vegetation

(structure).

Table 2. Changes in ecosystem function, structure and

composition that occur during succession.

ECOSYSTEM

ATTRIBUTE

ASSOCIATED CHANGES

Function

high rainfall interception,

efficient nutrient cycling, cooler

environment

(evapotranspiration cooling),

high filtration of air pollutants,

lower runoff.

Composition number of plant, wildlife and

microorganism species.

Structure presence of logs and snags,

layering of live vegetation, litter

accumulation.

Species composition, ecosystem structure and

ecosystem function all change during succession and

are linked. By changing one component, such as

composition, there will be changes in the

ecosystem's function and structure. Invasive plants,

for example, can modify the functioning of

ecosystems (such as nutrient cycling and

productivity) as well as their species composition

(Figure 18).

For example, Myrica faya has invaded young

volcanic areas in Hawaii. These areas are extremely

nitrogen-deficient, and no native nitrogen-fixing

plants exist. Because Myrica faya actively fixes

nitrogen, it can form dense stands which

out-compete and may replace native vegetation. Its

invasion completely alters nutrient cycling and the

rate and direction of primary succession (Vitousek

1986).

Figure 18.1 Photo by Edward Gilman

Figure 18.2 Photo by Edward Gilman

Figure 18. Several invasive plants, when introduced to

natural areas can modify the ecosystem's function and

alter natural succession. For instance, Chinese tallowtree

(Sapium sebiferum) (18.1 tree, 18.2 inflorescence), can

alter nutrient cycling and productivity by displacing native

vegetation in natural areas.

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 15

Changing Natural Succession: The

Casuarina Example

Casuarina species are nitrogen-fixing,

fast-growing species which are tolerant of infertile

soils. As a result, they would seem to be an excellent

choice for restoration projects, growing very fast,

shortening the reorganization and aggradation phases

and, consequently, reducing water runoff and

nutrient losses.

However, Casuarinas are also highly aggressive

invasive species (Figure 19). By planting them,

nitrogen is added to soils, altering the nutrient cycle.

A thick litter layer is also produced, reducing

germination of native plant species (Ewel 1986), and

altering the composition of plant species in the next

successional stage. Wildlife species are also affected,

since food sources and cover have been modified

(see also Chapter 9 - Invasive Plants).

Figure 19.1

Figure 19.2

Figure 19. Australian pine (Casuarina spp.), an

aggressive invasive species, alters composition, structure

and function of ecosystems. These fast-growing species

form monospecific stands (19.1) that displace native

vegetation. They are seen here growing above the original

ecosystem's canopy (19.2).

Managing Disturbances and

Succession

Natural disturbance regimes and succession

have often been altered by humans, such as through

the introduction of exotic species and the

suppression of natural fires. To restore ecosystems it

is necessary to actively manage succession.

Goals for restoring ecological succession could

be economic (e.g., reducing maintenance costs of an

urban park), ecological (e.g., restoring the normal

hydrological period of an urban wetland) or aesthetic

or recreational (e.g., bringing birds and watchable

wildlife back to a neighborhood greenspace). These

goals are not mutually exclusive. For example, the

Patuxent Wildlife Research Center, near Laurel,

Maryland integrates both ecological and economic

goals in the management of succession. In 1960, the

U.S. Fish and Wildlife Service and Potomac Electric

Power Company agreed to implement a management

program that would develop a shrubland community

on a newly constructed right-of-way. Mowing was

halted and selective herbicides were periodically

applied to undesirable tree species. After 30 years,

the right-of-way was dominated by a shrub

community with high diversity and heavy use by

wildlife (Obrecht et al. 1991). Additionally, the

economic goal of reducing the number of trees

growing too close to powerlines has also been

achieved.

A restored site (an urban park, for instance) may

contain one or more types of ecosystems or remnants

of ecosystem. It is important then, to understand

historical patterns of succession in these ecosystems.

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 16

Information should be regularly collected to

document patterns and effects of management,

including current and historical site conditions, such

as soils, vegetation and disturbances. A site

inventory should be conducted to determine the

potential of the site (see also Chapter 7 - Soil and

Site Factors). If a location is too degraded (due to

pollution, nutrient loading, or heavy pesticide use), it

may not be possible to restore it to a desired

historical successional stage. Realistic and feasible

restoration goals will ultimately determine a project's

success.

A particular stage, or a mosaic of different

successional stages, may be chosen as the objective

of restoration, based on the information collected

from the site inventory. The plant species to be

established should be those characteristic of the

corresponding natural successional stages. For

instance, planting trees and shrubs to attract as many

bird species as possible, many of which are not

typical of the desired successional stage, may not

lead to a sustainable objective.

Incorporating disturbances and succession

into small scale projects

Restoration projects in small areas may include

ecosystem(s) in which succession can be effectively

managed. These situations may include the

restoration of a bare site, elimination of invasive

species or re-introduction of more natural

disturbances.

Restoring bare sites

On a bare site, one stage of succession could be

chosen and a first effort to restore it could be by

planting a mix of all species typical of that

successional stage. However, it may take decades for

the trees to become mature, and litterfall and logs

may need to be imported if a late successional stage

is to be approximated. Introduction of natural

disturbance regimes, such as frequent ground fire,

may be desirable or necessary in some cases.

The Greening the Great River Park Program,

established in 1995, seeks to restore native

ecosystems along the Mississippi River in St. Paul,

MN. The project involves the landscaping of

industrial lands with four native plant ecosystems,

including forests and prairies. For example, a 35-acre

project will restore a natural prairie ecosystem close

to downtown St. Paul (Figure 20). Prairies will be

maintained in a grassy successional stage by using

frequent low intensity fires. "Prescribed fire" and/or

shrub/tree cutting will be used to maintain this

grass-like stage and keep weeds under control. Such

strategy will provide, in the long run, an important

successional stage that was missing from this

urbanized landscape.

Figure 20.1 Photo courtesy of Chicago Wilderness

Eliminating invasive species

In some sites, removal of invasive plants may be

sufficient to release native species from competition

and restore natural succession. In the Ivy Removal

Project in Forest Park, Portland, removal of English

ivy (Hedera helix) has renewed the health of the

existing vegetation (Figure 21). English ivy is an

aggressive exotic vine, extensively planted in the

surrounding neighborhoods, that has invaded the

park and suppressed its native vegetation. Regular

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 17

Figure 20.2 Photo courtesy of Greening the Great River

Park

Figure 20. Prairies are maintained in a grassy

successional stage by frequent low intensity fires (20.1).

The Greening the Great River Park initiative (20.2), uses

prescribed fire and/or cutting to maintain the grass

successional stage of prairies in a 35-acre project in

downtown St. Paul, MN.

removal of ivy has allowed native plant species to

follow natural succession by eliminating plant

competition.

Figure 21. The Ivy Removal Project, removes English ivy

(Hedera helix) that has invaded Forest Park in Portland,

OR, suppressing its native vegetation. In this case,

removal is sufficient to release native species from

competition and bring back natural succession.

However, in cases where the site has been

invaded by aggressive invasives and native

vegetation has been seriously damaged, removal of

invasives may have to be followed by planting. A

mix of native plant species typical of the desired

successional stage can be planted (as in the bare site

situation). An example occurred at Bill Baggs, a

heavily used urban park in Miami FL, where a

hurricane destroyed the monoculture of Australian

pines (Casuarina equisitifolia) that previously

dominated the park's vegetation (Figure 22).

Figure 22.1

Figure 22.2

Figure 22. Australian pine (Casuarina equisitifolia), a

highly invasive species, covered major areas of this urban

park, Bill Baggs (22.1, beyond buildings) and suppressed

native vegetation. After hurricane Andrew struck (22.2)

natural removal of Australian pines allowed managers to

restore the park's natural ecosystems.

Australian pines covered major areas of the park

and suppressed the native vegetation prior to the

hurricane. The "clean slate" that resulted from this

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 18

natural removal of Australian pines allowed

managers to reestablish the ecosystems that existed

before by planting native species typical of that area.

For more information on invasive species see

Chapter 9 - Invasive Plants.

Re-introducing natural disturbances

When re-introducing disturbances, ecosystem

characteristics and site conditions should be carefully

considered. In the Southern U.S., for example,

upland ecosystems are adapted to frequent (every 1

to 15 years) low intensity fires. In the case where fire

has been absent for long periods of time, thinning of

trees and/or manual removal of excessive fuel loads

may be necessary prior to application of prescribed

fire. Such management practice would prevent

damage (and other associated risks) by a high

intensity fire to which this ecosystem is not

adapted.

On the other hand, where high intensity

disturbances have been excluded for excessively

long periods, other strategies may need to be

pursued. For instance, the sand pine scrub

ecosystems, also in the Southern U.S., are adapted to

infrequent (every 15 to 100 years) high intensity

fires. Historically, after a lengthy fire-free period, an

intense fire occurs. If fires become too frequent, sand

pines disappear, and the association becomes oak

shrub or changes to other pines. If fires become too

infrequent, a xeric hardwood forest develops. Most

scrubs naturally depend on fires, but these fires need

to be applied in such a way that various stages of

development are maintained within isolated

fragments. Without these fragments, species with

special habitat requirements (such as the endemic

Florida mouse, Podomys floridanus, the Florida

scrub lizard, Scelopors woodi, the gopher tortoise

(Gopherus polyphemus) and the sand skunk, Neoseps

reynoldsi) might be eliminated (Figure 23).

Although preliminary steps have been taken to

develop techniques to burn the scrub, reintroduction

of fires in scrub ecosystems within urban areas may

not be feasible (due to liability, fire control

considerations and public reaction). In such areas,

patches of the scrub ecosystem could be maintained

by cutting, scraping and chopping to simulate fires

(Meyers and Ewel, 1990). Implementation of either

burning or mechanical techniques will require careful

attention to public education.

Figure 23.1 Photo by Anne Birch

Figure 23.2 Photo by Dave Rich

Figure 23. In the scrub ecosystem of the southern U.S.,

the correct frequency and intensity of fire is critical. If fires

become infrequent and too intense, a sand pine

ecosystem develops, excluding the endangered scrub

lizard (Sceloporus woodi) (23.1) and gopher tortoise

(Gopherus polyphemus) (23.2).

In other ecosystems, small or large gaps may

need to be cut to stimulate further succession. Such a

practice is becoming common for restoration of

longleaf pine ecosystems in the Southeastern U.S.,

where dense hardwood thickets now dominate many

sites. Gaps are cut and regenerated (Figure 24), and

prescribed fire is used to keep hardwoods from

re-invading.

Re-instating several different stages of

succession in one area can only be achieved on very

large land areas. Small sites may prove not to be

functional, although a small mosaic of semi-natural

successional stages may, nevertheless, be effective in

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 19

Figure 24.1

Figure 24.2

Figure 24. In the longleaf pine ecosystems in the

southeastern U.S., gaps are cut to stimulate succession

(24.1). Such practice allows regeneration (24.2) and the

return of a missing stage of succession to the landscape.

schoolyards for educational purposes. The

Schoolyard Ecosystems for Northeast Florida

initiative, for example, teaches students about

different animals that utilize a combination of small

patches of mowed areas, early succession and more

mature areas (Figure 25). Some important structural

elements, such as logs, snags, brush piles and plants

with different heights, are constructed to simulate a

more mature area and to promote wildlife.

Figure 25.1

Figure 25.2

Figure 25. The Schoolyard Ecosystems for the Northeast

Florida initiative (25.1) encourages the establishment of

successional stages in school areas. The objective is to

teach students about different animals that utilize a mowed

area, an early successional patch and a more mature area

(25.2).

Incorporating disturbances and succession

into large scale projects

Parts of larger project areas (greater than about

20 acres) may present situations similar to small

scale projects (with some bare sites, sites invaded by

exotic invasive species and sites where disturbances

could be re-introduced). But in larger areas, there is

also the opportunity to manage for several stages of

succession at the same time, if a mixed successional

landscape is typical of the ecosystem in question or

could be used for educational purposes. Learning

about the ecosystem, its stages of succession and

how they fit into the overall landscape becomes

critically important. The Chicago region, for

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 20

example, contains prairies, savannas, woodlands and

forests. The absence of fire has impacted these

ecosystems and their stages of succession in the

landscape. Oak savannas have been almost totally

excluded in the Chicago area and prairies have been

invaded by woody species. Historically, the

frequency and intensity of fire determined the

successional stage of these ecosystems, that is,

whether a given piece of land would be an open

grove or a dense forest (Figure 26). Restoration

efforts in this case are based on re-introducing fires.

To date, fire has been reintroduced in several areas

and native species typical of the region's ecosystems

are being planted. In some areas, native trees have

been cut to allow more light to reach the ground

(Figure 27). Such practices allow the landscape to

support several stages of succession, ranging from

open prairies to forests.

Figure 26. Historically, the frequency and intensity of fire

determined the successional stage of ecosystems

(whether a given piece of land would be an open grove or

a dense forest) in the Chicago area. Photo courtesy of

Chicago Wilderness

Figure 27.1 Photo courtesy of Chicago Wilderness

Figure 27.2 Photo courtesy of Chicago Wilderness

Figure 27. Due to suppression of fires, the once open

savannas in the Chicago area (27.1) developed into

thickets of vegetation deprived of sunlight (27.2). Oak

savannas began losing their vast diversity of plants and

animals and were almost excluded from the landscape.

Some continuous or intermittent form of

management may be needed to create disturbances in

situations where human activity has severely

modified natural disturbances cycles. Efforts to

restore historical flooding cycles in the South Platte

River watershed illustrate the need for an integrated

restoration plan for a whole region. The floodplains

along the South Platte river in Nebraska consist of a

mosaic of different vegetation types. The presence of

wooded or open vegetation was historically

determined by natural periodic floods. Forests were

confined to drier sites, since native woody species,

such as willows (Salix spp.) and cottonwoods

(Populus spp.), would not survive flooding. Grasses,

on the other hand, could tolerate flooding, allowing

for open areas along the river.

Channelization and upstream development

reduced the water flow and, consequently altered

flooding periods. As a result, previously open areas

of the floodplain are nowdrier and invaded with

adjacent native forest species. Before channelization

and development, migratory birds, such as the

endangered whooping crane (Grus americana) and

the sandhill crane (Grus canadensis) (Figure 28),

used the open grassy floodplains for feeding and

avoided roosting in areas with abundant woody

species. Because of these changes in natural

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 21

succession, the whooping crane population decreased

80% over 30 years.

Figure 28. Sandhill crane (Grus canadensis) populations

have decreased as a consequence of successional

changes in ecosystems along the South Platte River.

Photo by Larry Korhnak

Current restoration efforts include selective

clearing of trees along some parts of the river.

However, restoration of historical patterns of

succession in the region will ultimately depend on

the reinstatement of normal flood periods. An

integrated upstream restoration effort along all the

South Platte River extension will be required to

achieve such a goal (U.S. Fish and Wildlife Service

1981).

In another example from Central Florida, scrub

vegetation without fire grows very tall and thick with

very little open space for the endangered gopher

tortoise (Gopherus polyphemus) to nest and feed

(Figure 29). Little sunlight can reach the ground and

herbs, which are a food source for this tortoise, can

no longer grow (Smith 1997). Conservationists are

using prescribed fires to restore the open nature of

the historic scrub ecosystem. A number of other

animals with wide ranges, such as black bear,

white-tailed deer, bobcat, gray fox and spotted skunk,

also utilize the scrub and should benefit from the

efforts as well (Meyers and Ewel 1990).

Figure 29. Without fire the scrub ecosystem grows very

tall and thick with very little open space for the endangered

gopher tortoise (Gopherus polyphemus) to nest and feed.

Photo by Ben Coffin (with the Friends of the Enchanted

Forest in Titusville, FL)

Conclusions

Disturbances and succession occur virtually in

every place on earth. To successfully manage the

urban forest ecosystem, managers need to understand

natural disturbance regimes and how species

composition, ecosystem structure and wildlife

interact over time within these regimes.

There are many opportunities to incorporate the

concepts of disturbance and succession in either

small or large scale urban restoration projects:

• Learn about the historical disturbance regimes

that occur in the ecosystems in your region.

Remember that disturbances have a variable

spatial and temporal scale. If appropriate,

propose re-introducing some disturbances back

to these ecosystems.

• Understand the successional stages of the

ecosystem(s) you are managing.

• Take advantage of any research conducted that

relates to historical site conditions, including

soils, climate, vegetation and disturbances.

Conduct a site analysis and decide whether your

restoration plans should include disturbances and

succession management.

• Manage site-specifically but remember that the

site you are managing belongs to a larger

landscape that may contain other successional

stages.

• Remember that species composition,

ecosystem structure and ecosystem function are

linked and change during succession. Invasive

plants, for example, can modify the functioning

and structure of ecosystems as well as their

species composition.

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 22

• Start with small demonstration projects.

Remember that succession and natural

disturbances do not always follow our human-made

geographical boundaries. Integrated efforts may be

needed to better achieve restoration goals at the

landscape level.

It is also important to involve the local

community in every step of the restoration process.

Successful urban forest restoration projects often

include an educational and outreach component.

Educate people about the benefits of succession and

the benefits of re-introducing natural disturbances.

Suggested Readings

Adams, L. and L.E. Dove. 1989. Wildlife

reserves and corridors in the urban environment: A

guide to ecological landscape planning and resource

conservation. Columbia, MD: National Institute for

Urban Wildlife.

Adams, L. W. 1994. Urban wildlife habitats: A

landscape perspective. Minneapolis, MN: University

of Minnesota Press.

Franklin, J.F. 1993. Preserving biodiversity:

Species, ecosystems or landscapes? Ecological

Applications 3(2): 202-205.

Smith, D.S. and P.C. Hellmund. 1993. Ecology

of greenways: Design and function of linear

conservation areas. Minneapolis, MN: University of

Minnesota.

Cited Literature

Bormann, F.H. and G.E. Likens. 1979. Pattern

and process in a forested ecosystem. New York, NY:

Springer-Verlag.

Connell, J.H. 1978. Diversity in tropical rain

forests and coral reefs. Science 199: 1302-1310.

Eckert, A.W. 1974. The owls of North America.

New York: Doubleday and Co.

Ewel, J.J. 1986. Invasibility: Lessons from

South Florida. In Ecology of biological invasions of

North America and Hawaii, edited by H.A. Mooney

and J.A. Drake. Berlin, Germany: Springer-Verlag.

Meyers, L. and J.J. Ewel. 1990. Ecosystems of

Florida. Gainesville, FL: University of Central

Florida Press.

Neilson, E.L. Jr. and D.E. Benson. 1991.

Wildlife Habitat Evaluation Handbook. Colorado

State University: Department of Fishery and Wildlife

Biology.

Obrecht, H.H.III, W.J. Fleming and J.H.

Parsons. 1991. Management of powerline

rights-of-way for botanical and wildlife value in

metropolitan areas. In Wildlife conservation in

metropolitan environments, edited by L.W. Adams

and D.L. Leedy. Columbia, MD: National Institute

for Urban Wildlife.

Perry, D.A. 1994. Forest ecosystems. London:

The Johns Hopkins University Press.

Pickett, S.T.A. and P.S. White. 1985. The

ecology of natural disturbance and patch dynamics.

New York, NY: Academic Press, Inc.

Platt, W J., G.W. Adams and S.L. Rathbun.

1988. The population dynamics of a long-lived

conifer (Pinus palustris). American Naturalist

131:491-525.

Smith, R.B. 1997. Gopher tortoises (Gopher

polyphemus). Kennedy Space Center and Enchanted

Forest Nature Sanctuary, October 16 1997 [cited

1997]. Available from

http://www.nbbd.com/godo/ef/gtortoise/index.html

Turner, M.G. 1987. Landscape heterogeneity

and disturbances. New York: Springer-Verlag.

U.S. Fish and Wildlife Service. 1981. The Platte

River ecology study special research report. U.S.

Fish and Wildlife Service, Jamestown, ND.

Jamestown, ND: Northern Prairie Wildlife Research

Center Home Page [cited July 16 1997]. available

from

http://www.npwrc.usgs.gov/resource/othrdata/

platteco/platteco.htm

Vitousek, P.M. 1986. Biological invasions and

ecosystem properties: Can species make a

difference? In Ecology of biological invasions of

North America and Hawaii, edited by H.A. Mooney

and J.A. Drake. Berlin, Germany: Springer-Verlag.

Chapter 4: Plant Succession and Disturbances in the Urban Forest Ecosystem 23

Wood, P.B., J. Schaefer and M.L. Hoffman.

1990. Helping our smallest falcon: The Southeastern

American kestrel SS-WIS-16. Gainesville, FL:

Florida Cooperative Extension Service, University of

Florida.

Woolfenden, G.E. and J.W. Fitzpatrick. 1984.

The Florida scrub jay: Demography of a

cooperative-breeding bird. Monogr. Populat. Biol.

no. 20. Princeton, New Jersey: Princeton University

Press.

Chapter 5: Developing a Restoration Plan That Works1

William G. Hubbard2

1. This is Chapter 5 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. William G. Hubbard, Southern Regional Extension Forester, Cooperative Extension Service, The University of Georgia, Forest Resources Bldg. 4-402,

Athens, GA 30602-4356.

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

A plan can be defined as a predetermined course

of action. Regardless of the type of plan, they all

have a number of similar components. First a vision

- a future desired condition or state - must be defined.

Goals and objectives are then used to achieve the

vision. Measurable goals and objectives form a basis

for project evaluation. Guiding principles are

incorporated into the goals and objectives to ensure

that achievement of the vision is attained in a high

quality and defendable manner. It is important to

identify and involve stakeholders in the planning

process from the beginning and to have a framework

and a process to identify and resolve issues.

Gathering and analyzing information about the

restoration site is critical. An action plan with a

timeline outlines activities and responsibilities. A

plan for monitoring should be developed before the

project is started. Monitoring evaluates how well the

project objectives have been met. Determining

project costs, benefits and funding sources is

essential to the restoration project's success. As the

plan progresses, care should be taken to outline its

relationship to other plans. A well-thought-out,

well-developed plan will help the community

achieve its vision.

Introduction

According to many planners, a plan can be

defined as a predetermined course of action. Plans

have three characteristics: they must involve the

future, they must involve action and they must involve

an element of personal or organizational

identification or causation. In other words, plans are

designed to get someone or something (a business

for example) from point A to point B in a certain

time frame. This will most likely be accomplished

by someone or a group of people taking actions

toward the stated goal(s) and objective(s) (Figure 1).

Figure 1. Plans provide a common vision and a path

toward its accomplishments. Photo by Larry Korhnak

Chapter 5: Developing a Restoration Plan That Works 2

But why develop a plan? We have heard all the

lines before and if we are not careful we will fall into

the same cynical trap of thinking about why we don't

like to plan and why plans don't work. For example,

plans:

• sit on the shelves and collect dust!;

• rarely succinctly develop the goals, objectives

and pathways to success;

• are shaped by politics or personnel changes

which often render them useless;

• often become outdated as soon as they are

done; and

• don't fit today's style of managing by the seat

of our pants!

However, what can a plan provide?

• a common vision for the community;

• well-defined and measurable goals and

objectives;

• a logical plan of action;

• organized and focused efforts toward

accomplishing a goal;

• a document to assess and justify budgetary

requirements; and

• a plan to obtain funding.

Principles of Planning

Larsen et al. 1990, reviewed many plans and

provided a number of suggestions for principles of

good planning. His tips are to:

1. Integrate and balance resource allocations.

Good planning integrates all urban resources. It

does not pit one resource against another.

2. Communicate a clear vision. Good planning

generates a clear vision of the outcomes and

contributions to meeting local, regional, and

national needs.

3. Recognize limits. Good planning recognizes

limits on the outcome's ability to produce a mix

of goods and services in perpetuity.

4. Seek informed consent. Good planning

welcomes citizen involvement. Decisions

should be made and explained openly. Dialogue

among disparate interests should be facilitated.

5. Finish in a reasonable time. Good planning is

completed in a reasonably short period of time.

Short periods facilitate incremental planning and

stability among key players. People can actually

harvest the fruits of their labor.

6. Be people-oriented. Good planning recognizes

that individuals, both inside and outside the

agency or effort, make the difference between

good and bad plans (Figure 2).

7. Promote active administrative leadership. Good

planning requires active involvement and

leadership on the part of responsible

administrators.

8. Match analysis to questions at hand. Good

planning involves use of analytical tools for

purposes of evaluating options. Such tools

should not drive or dominate the process.

9. Be both locally oriented and nationally

balanced. Good planning should be locally

oriented and should also give ample

consideration to national constituencies.

Types of Plans

Before we begin the nuts and bolts of urban

forest ecosystem restoration planning let's review

some of the more common types of plans:

Strategic Plan

Strategic planning can be defined as a

disciplined effort to produce fundamental decisions

and actions that guide an organization. This kind of

planning typically involves broad-scale information

gathering, an exploration of far-reaching alternatives,

an emphasis on future implications of present

decisions and an ability to accommodate divergent

interests and values (Bryson, 1988).

Chapter 5: Developing a Restoration Plan That Works 3

Figure 2. Good planning recognizes that individuals, both

inside and outside the agency or effort, make the

difference between good and bad plans. Photo by Larry

Korhnak

Comprehensive Plan

Comprehensive planning involves taking into

account as many planning needs as possible under

one umbrella plan. The comprehensive plan often

involves stakeholder input early on. Many counties

and cities now undergo comprehensive planning

which includes plans for economic development,

land-use plans and environmental plans.

Master Plan

Similar to the comprehensive plan, the master

plan is not as comprehensive and involves more

specific goals and objectives. Master Street Tree

Plans of the past for example involved planting

plans, maintenance plans, budgetary plans and

educational plans.

Operational Plan

The operational plan can be defined as that

which puts the strategic, comprehensive or master

plan into action. It outlines who is responsible for

what by when. Activities are often outlined on a

timeline with expected outcomes.

Management Plan

Similar to the operational plan but more

detailed, the management plan might even outline

day-to-day management activities that need to be

accomplished in order to achieve the stated goals and

objectives.

Restoration Plan

As we willl see later, a restoration plan is merely

a type of management, master or action plan that

focuses on restoring specific areas.

Budget or Fiscal Plan

The budgetary or fiscal process of any

organization or entity is usually complex. Monetary

management is complex because it equates very

closely to people's value systems. Budgetary

instructions, accounting procedures, etc., are all

enclosed in this important type of plan.

Communication and Education Plan

A final plan worth mentioning is the

communication and education plan. In a sense, this

is a strategic plan where appropriate communication

of goals, objectives, issues and progress is vitally

important to the success of any plan. Special care

must be given to produce a good communication

plan.

Etc. Etc. Etc. Plan

Plans are made for everything these days.

Land-use plans, zoning plans, etc. The importance is

not necessarily the specific name of the plan but what

it purports to achieve. It is also interesting to point

out that plans are often nested and involve a systems

approach (Figure 3).

Components of the Restoration

Plan

Regardless of the type of plan, they all have a

number of similar components. In the following

sections we will discuss several of these components.

We will also discuss some of the issues involved in

creating a successful plan. Specifically, the

following outline will be followed for developing a

restoration plan:

• Scope, Vision, Goals and Objectives

• Guiding Principles

Chapter 5: Developing a Restoration Plan That Works 4

Figure 3. An example of a systematic approach to

planning involving many different plans.

• Stakeholder Involvement

• Identifying Problems and Issues

• Information Gathering and Analysis

• Developing a Timeline and Detailing Actions -

the Action Plan

• Monitoring and Evaluating

• Budget and Finance

• Relationship to Other Plans

Scope, Vision, Goals and Objectives

Scope

Before we look at vision, goals and objectives it

is important to understand the scope of the proposed

restoration project. This will have an important

influence on the development of the plan. Many

times, this is the difference between a restoration

project versus a restoration program or one project

versus many projects. For example, community or

ecosystem-wide plans are different from a plan

specifically designed for a section or plot of land in

an urban area. Regardless of the size or scope,

planning techniques are very similar. The

complexity and interrelationships distinguish the

two. Scope is important to keep in mind when

initiating the planning process.

Vision

Plans are based on vision. Vision involves

creativity, imagination, and sometimes thinking

outside of the box. Basically, the vision is the

desired future condition or state (Figure 4). It is the

result of closing your eyes and literally visioning

what the outcome of your plan might look like. A

shared vision is critical if you want everyone's

buy-in (see below for stakeholder input).

Figure 4. A vision is the desired future condition or state.

Greening the Great River Park in St. Paul, MN has a plan

for restoring industrial lands along the Mississippi River.

Their vision is to have these restored industrial areas look

like they were set in an established forest. Photos by Rob

Buffler

An excellent example is from Metro, the

regional government in Portland, Oregon. They are

working on what is called the Metropolitan

Greenspaces Vision:

It is our vision to protect, on a long-term basis,

natural areas, open spaces, trails and greenways

that lend character and diversity to our region

even as more and more people move here to

share our special place.

Chapter 5: Developing a Restoration Plan That Works 5

It is our vision to balance our urban focus and

drive for economic health and prosperity with an

array of wildlife habitats in the midst of a

flourishing cosmopolitan region.

It is our vision to conserve and enhance a

diversity of habitats woven into a lush web of

protected greenspaces. (Metropolitan

Greenspaces Master Plan, July 1992).

Goals and Objectives

Goals and objectives are used to achieve your

vision. Measurable goals and objectives form a basis

for project evaluation (Figure 5).

Figure 5. The Metropolitan Greenspaces Master Plan in

Portland, Oregon has a goal to restore green and open

spaces in neighborhoods where natural areas are all but

eliminated. Whitaker Ponds is one of the selected

neighborhood restoration sites. Photo by courtesy of

Metro Regional Parks and Greenspaces

Goals and objetives are actual steps, which if

taken in an orderly, strategic fashion will result in

attainment of the vision. For example, the goals for

the Metropolitan Greenspaces System include:

Create a cooperative regional system of natural

areas, open space, trails and greenways for

wildlife and people in the four-county

metropolitan area.

Protect and manage significant natural areas

through a partnership with governments,

nonprofit organizations, land trusts, interested

businesses and citizens, and Metro.

Preserve the diversity of plant and animal life

in the urban environment, using watersheds as

the basis for ecological planning.

Establish a system of trails, greenways and

wildlife corridors that are interconnected.

Restore green and open spaces in

neighborhoods where natural areas are all but

eliminated.

Coordinate management and operations at

natural area sites in the regional Greenspaces

system.

Encourage environmental awareness so that

citizens will become active and involved

stewards of natural areas.

Educate citizens about the regional system of

greenspaces through coordinated programs of

information, technical advice, interpretation and

assistance.

Another example of possible goals and

objectives comes from the Society for Ecological

Restoration (SER) and is based on a common

definition of ecological restoration. According to

SER, ecological restoration is the process of assisting

the recovery and management of ecological integrity.

Ecological integrity includes a critical range of

variability in biodiversity, ecological processes and

structures, regional and historical context, and

sustainable cultural practices.

The definition above was developed by the SER

Policy Working Group after almost a year of

consultation and deliberation; it was passed by a mail

vote of the SER Board in October 1996. The SER

Policy Working Group is now working on a detailed

description of attributes, goals and objectives, which

will accompany the definition:

To restore highly degraded but localized sites;

To improve productive capability of degraded

production lands;

To enhance conservation values in protected

landscapes;

To enhance conservation values in productive

landscapes (Journal of Restoration Ecology

1995)

Chapter 5: Developing a Restoration Plan That Works 6

The Bill Baggs Cape Florida Restoration

Project Example

The Bill Baggs Cape Florida Restoration Project

(1992) can also be used to exemplify the

development of a vision, goals and objectives in a

restoration project. Bill Baggs is a heavily used

urban park near Miami. Prior to Hurricane Andrew's

strike in 1992, the park had extensive areas

dominated by Australian pine (Casuarina

equisitifolia), an invasive tree. The natural removal

of Australian pines by the Hurricane provided a great

opportunity to restore the park to conditions closer to

its previous natural conditions. The Bill Baggs Cape

Florida Park vision, goals, and objectives were:

Vision:

• To reforest the park with native vegetation

(Figure 6); and

• To improve the historical, recreational and

educational opportunities and the facilities

in the park (Figure 7).

Goals:

• The primary goal was to restore the park's

original natural processes while providing

compatible public recreational

opportunities;

• Reforest the park to predominantly native

vegetation for beneficial environment

purposes and for public outdoor recreation

benefits; and

• Eradicate exotic plants at Cape Florida and

re-establish the historic native natural

communities.

Objectives:

• Stabilize and protect the natural and

cultural resources of the park;

• Re-open public recreation areas as soon as

possible;

• Preserve and restore the original natural

communities and natural processes of the

park, to the extent possible; and

• Restore pre-hurricane levels of public

recreation.

Figure 6. The Bill Baggs Cape Florida Restoration Plan

was to reforest the park with native vegetation. Photo by

Mary Duryea

Figure 7. The second vision of the Bill Baggs Cape

Florida Restoration Project was to "improve the historical,

recreational and educational opportunities and the

facilities in the park." Photo by Mary Duryea

Guiding Principles

Guiding principles are incorporated into goals

and objectives to ensure that the plans vision is

attained in a high quality and defendable manner

(Figure 8).

Some guiding principles that have been used in

the past for example are:

Chapter 5: Developing a Restoration Plan That Works 7

Figure 8. Guiding principles such as sound scientific facts

are incorporated into goals and objectives to ensure that

the plan's vision is attained in a high quality and

defendable manner. Photo by Larry Korhnak

Science - Projects need to be planned and

supported by sound scientific facts and reasoning.

Stewardship - Ultimately, the goal of many

restoration projects is stewardship. Agreement

on what this means will be important.

Integration and partnership - Today's world

necessitates multi-discipline, agency/entity

involvement.

Economics - Sound economics insures the plan

matches the economic resources.

Stakeholder Involvement

It is important to identify and involve

stakeholders in the restoration planning process from

the beginning. Stakeholders are the people who will

be impacted by the restoration project. Buy-in from

community, government, independent organizations

(NGOs, Universities), private sector, investors,

employees/employer, among others is absolutely

necessary at an early phase. Failure to do so will

undermine the process and the plan and may be a

waste of time and money (Figure 9).

Figure 9. It is important to identify and involve

stakeholders in the restoration planning process from the

beginning. Photo by Mary Duryea

What kind of input will be necessary? Some of

the important questions you may ask at the outset

are: Who are your stakeholders and what

information do you want from them? Are they

members of the community that may be affected by

the decisions made? Make an extensive list of who

may have an interest in your restoration project.

Retreat-style settings, Delphi surveys and other

ways to gather input and understand issues have been

used to include stakeholders. The Delphi process was

originally developed in the 1950s by Olaf Helder and

Norman Dalkey, both scientists at the Rand

Corporation, as an iterative, consensus building

process for forecasting futures. It has since been

deployed as a generic strategy for developing

consensus and making group decisions in a variety of

fields. An interest group is typically assembled,

either through correspondence or face-to-face

discussion, to assess issues of mutual concern.

While the individuals in the group share a

common interest (the subject of the Delphi), they

usually represent different points of view. Each

member of the group is asked to give his/her

comments regarding a particular set of issues. A

facilitator analyzes the individual comments and

produces a report documenting the response of the

group. The individuals then compare what each

person said to the group's normative response as a

basis for discussion. The discussion, again via

remote or face-to-face conversation, is used to share,

promote, and challenge the different points of view.

Once this is done, the participants, having the benefit

of the previous discussion, anonymously comment

on the issues again. A new group report is generated

and the process repeats itself. This process continues

until the group reaches consensus or stable

disagreement.

Chapter 5: Developing a Restoration Plan That Works 8

If you would like further information about

stakeholder involvement and identification, and the

Delphi process, check the Suggested Readings

section at the end of this chapter.

Identifying Problems and Issues

When involving stakeholders it is important to

have a framework and a process to identify and

resolve issues (Figure 10).

Figure 10.1 Photo by Larry Korhnak

Figure 10.2 Photo by Larry Korhnak

Figure 10. When involving stakeholders it is important to

have a framework and a process to identify and resolve

issues, such as issues concerning compatible recreational

uses.

Examples of identification include expert review

of your project from a university faculty member or

private consultant or public review through town hall

meetings or forums, the media, etc. The issues

confronting the project may be social, economic and

environmental. Addressing these issues will help to

revise and shape the restoration plan. Some example

issues may include:

• Compatible recreational uses;

• Biological and physical limitations for the site;

• Consensus on vision, goals and objectives;

• Private property rights issues;

• Land conflicts;

• Conflicts with current infrastructure;

• Conflicts with other plans; and

• Compatibility with laws and regulations.

Information Gathering and Analysis

Once your vision, goals/objectives, guiding

principles and stakeholder input have been

determined, a next logical step will be to determine

where to obtain the information you will need for the

restoration project (Figure 11).

Figure 11. Information gathering and analysis such as this

site assessment of a wetland will guide the development

of goals and objectives. Photo by Larry Korhnak

The information gathering and analysis phase

might incorporate the use of the following tools:

Natural Resources

1. aerial photographs/remote sensing data

2. geographical information systems (GIS)

Chapter 5: Developing a Restoration Plan That Works 9

3. field data collection

4. soil maps

5. climatic data

Historical

1. library

2. historical societies

3. municipal records

Infrastructure

1. GIS

2. city and utility agencies

Community/Social

1. stakeholder input and others

2. town meetings and focus groups

Where can you go for this information? More

and more can be obtained from the Internet. GIS

maps and data, soils information, climatic data, etc.

are sometimes located on various websites. Other

information can be found at the public works or

other municipal departments. Social and stakeholder

data usually needs to be collected first hand as

discussed previously.

Following this very important step of data

collection and analysis it may be necessary to refine

or redirect the current vision, goals and objective.

For example, stakeholder input may be needed again

as you collectively review the results from GIS

maps. A real problem in some parts of the country

for example is the control and management of

invasive exotic species. The vision may have been

the complete eradication of all invasive species in a

given geographical location. Review of maps and

other data, however, may render achievement of this

vision extremely costly or impossible. A renewed

vision may be a healthy ecosystem with a

manageable level of this invasive species and

complete eradication of it on public lands.

Stakeholders will need to understand why the vision

has been revised. Maps are an excellent way to

communicate.

Developing a Timeline and Detailing

Actions - The Action Plan

Once agreement has been coalesced, the next

step is to outline the beginning of an action plan. In

general, there is more than one way to reach the plans

objectives. Successful restoration projects often

spend time early on identifying, evaluating and

selecting alternative paths and solutions. Various

criteria are used to reach consensus on the proper

alternatives to use. Economic analysis (cost-benefit,

capital budgeting, social accounting methods, etc.) is

one way. Public input and voting is another. It is

important to remember to use the guiding principles

to choose the best alternative.

An example of restoring a longleaf ecosystem in

an urban setting using three alternatives should

illustrate this. The restoration team and stakeholders

determined three potential courses of action after

extensive discussion involving restoring a 15-acre

tract of land in a metropolitan area.

Roller drum and chop site. Plant two-year-old

containerized longleaf pine seedlings, burn

regularly, keep nuisance wildlife out with

fencing. Monitor health and regeneration

success.

Leave existing vegetation on the site. Plant

six-year-old longleaf pine saplings. Apply

herbicides.

Seed the area after a light winter burn.

Manually remove the weeds, brush and

competition.

Following the decision to follow one alternative,

the next step is detailing the actions. Basically,

action planning states what will be done, by whom,

and when. It includes a timeline and estimated costs

and resource needs (Figure 12).

One thing that is often overlooked is developing

a system for foreseeing and overcoming barriers in

action planning. The best systems involve enhanced

communication plans with the general public,

stakeholders, consultants and others involved in

developing and implementing the plan.

Chapter 5: Developing a Restoration Plan That Works 10

Figure 12. An example action plan timeline.

Monitoring and Evaluating

The next step is monitoring and evaluating the

plan's effectiveness. How do you do this? Some

examples relating to the regeneration restoration

project cited before include:

Site visits

1. regeneration surveys

2. hydrologic and soils testing

3. testing and evaluating the ecosystem

structure and functioning

Physical mapping

1. aerial photography

2. GIS mapping

Social

1. public reaction

2. benefits and effects on neighbors

It is important to have a plan for monitoring

before the project is begun (Figure 13). Monitoring

may begin with base-line data collection and

continues on during project implementation.

Monitoring evaluates how well the project's

objectives have been met. It demonstrates and

elucidates both successes and failures.

Figure 13. A plan for monitoring should be developed

before the project is started. Monitoring evaluates how

well the project objectives have been met. Photo by Larry

Korhnak

Budget and Finance

Determining project costs, benefits and funding

sources is essential to the restoration project's

success (Figure 14). Following are a few questions

that the planning/implementation team, along with

stakeholders, policy makers and others need to

address.

Figure 14. Determining project costs, benefits and funding

sources is essential to the restoration projects success.

Photo by Larry Korhnak

Chapter 5: Developing a Restoration Plan That Works 11

What will this project cost? What are the

benefits?

Benefit-Cost Ratio: In this type of analysis, the

project is undertaken when the benefit to cost

ratio is greater than one. If more than one

project is desired, then the project with the

highest ratio is undertaken.

Net Present Benefits (NPB): Due to the nature

of many public projects, it may take many years

to reap the full benefits. To take into account

the long-term nature of these projects, all costs

and benefits are equated to a common time

(usually the present). If there is anything left

after subtracting net present costs from net

present benefits, the project will be of value to

the community and can be judged as

economically sound, all else being accounted for.

Capital Budgeting: In many instances, a capital

budgeting process will need to be invoked.

Ranking of competitive projects by benefit-cost

ratio or net present benefits may help in the final

analysis. Great care should be taken to outline

the assumptions used and to equate all projects

as to scale and time.

Use of other economic tools: Be sure to review

the literature for more information that may be

useful, specifically opportunity cost and the

traditional economic tools that have been

modified for the new fields of ecological and

environmental economics.

What are the Funding Mechanisms?

Some funding options to investigate include:

• special options tax

• bond issuance

• general tax revenues

• private foundations

• public and private grants

Robert Miller's Urban Forestry textbook (Miller

1997) lists a number of funding mechanisms that can

be investigated. Finally, many successful plans have

been implemented because they were already

developed and the right funding came through. The

importance of having a plan ready when budget

opportunities become available cannot be stressed

enough. Timing and preparedness go hand-in-hand.

For references and additional information on budget

and finance issues check the Suggested Readings

session at the end of this chapter.

Relationship to Other Plans: Plans are

Interrelated

As the planning process proceeds, it will

become obvious that no longer can we plan in a

vacuum. The interrelationship and interdependence

of planning is more relevant today than ever before.

In addition, many citizens are beginning to realize

that a healthy economy is tied directly to a healthy

ecosystem, making environmental planning very

important. More communities are incorporating a

systems approach to planning that is similar to

comprehensive planning (Figure 15).

Figure 15. As the plan progresses, care should be taken

to outline its relationship to other plans. Photo by courtesy

of Metro Regional Parks and Greenspaces

As your plan progresses, care should be taken to

outline its relationship to other plans. These plans

include:

• Comprehensive

• Transportation

• Land

Chapter 5: Developing a Restoration Plan That Works 12

• Capital improvement

• Risk management and hazard assessment

• Community facilities and utilities plan

• Public outreach

1. media

2. schools

3. professional groups

• Volunteer action plan

Conclusion

Urban ecosystem restoration planning is a

highly complex and dynamic process. As with any

process, there are innumerable factors to consider

and no cookbook solutions. A careful review of the

literature and of other plans from around the country

should be beneficial to anyone considering

restoration plan development. A well-thought-out,

well-developed restoration plan will help the

community achieve its vision (Figure 16).

Figure 16. A well-thought-out, well-developed restoration

plan will help the community achieve its vision. Photo by

Larry Korhnak

Suggested Readings

Woodley S., J. Kay and G. Francis. 1993.

Ecological Integrity and the Management of

Ecosystems. St. Lucie Press. 220 p.

Miller, R. 1997. Urban Forestry: Planning and

Managing Urban Greenspaces. Upper Saddle River,

New Jersey: Prentice Hall. 502p.

For more information about the Delphi process:

Adler, M. and E. Ziglio (eds.) Gazing Into the

Oracle: The Delphi Method and Its Application to

Social Policy and Public Health. London: Kingsley

Publishers (in press).

Delbecq, A.L., A.H. VandeVen and D.H.

Gustafson. 1975. Group Techniques for Program

Planning: A Guide to Nominal Group and Delphi

Processes. Scott & Co.

Linstone, H. and M. Turoff. 1975. The Delphi

Method: Techniques and Applications. Addison

Turoff, M. 1970. The Policy Delphi. J .of

Technol. Forecast. and Soc. Change, 2(2):

Turoff, M. 1972. Delphi Conferencing:

Computer Based Conferencing with Anonymity. J

.of Technol. Forecast. and Soc. Change, 3(2): 159

Turoff, M. 1974. Computerized Conferencing

and Real Time Delphis: Unique Communication

Forms. Proceed. 2nd International Conference on

Computer Communications, 135

For more information about stakeholders:

The World Bank Participation Sourcebook

(Chapter III: Practice Pointers in Participatory

Planning and Decisionmaking) (on line at:

www.worldbank.org/wbi/sourcebook/sb03.htm).

Fischman, R. L. and M. S. Squillace. 2000.

Environmental Decisionmaking. Anderson

Publishing Co. third edition.

Chopra, K., G.K. Kadekodi and M.N. Murti.

1989. Participatory Development: People and

Common Property Resources. New Delhi: Sage.

For more information about budgeting and

finance:

Agarwal, A. and S. Narain. 1989. Towards

Green Villages: A Strategy for Environmentally

Sound and Participatory Rural Development. New

Delhi: Centre for Science and Environment.

Brown, G. and C.B. McGuire. 1967. A Socially

Optimal Pricing Policy for a Public Water Agency.

Water Resources Research.

Chapter 5: Developing a Restoration Plan That Works 13

Clark, C.W. 1976. Mathematical

Bioeconomics: The Optimal Management of

Renewable Resources. New York: John Wiley.

Costanza, R. ed. 1991. Ecological Economics:

The Science and Management of Sustainability New

York: Columbia University Press.

Dasgupta, P., S. Marglin and A. Sen. 1972.

Guidelines for Project Evaluation. New York:

United Nations.

Dixon, J.A. and M.M. Hufschmidt eds. 1986.

Economic Valuation Techniques for the

Environment. Baltimore: Johns Hopkins University

Press.

Tietenberg, T. 1988. Environmental and

Natural Resource Economics, 2nd ed. Glenview, Ill.:

Scott, Forsman.

Cited Literature

Bryson, J. M. 1988. Strategic Planning for

Public and Nonprofit Organizations. San Francisco,

California: Jossey-Bass Publishers.

Larsen, G., A. Holden and D. Kapaldo. 1990.

Synthesis of Critiques of Land Management

Planning. USDA-Forest Service, Washington:

FS-452. Policy Analysis Staff.

Miller, R. 1997. Urban Forestry: Planning and

Managing Urban Greenspaces. Upper Saddle River,

New Jersey: Prentice Hall. 502p.

Metropolitan Greenspaces Master Plan. 1992.

A Cooperative Regional System of Natural Areas,

Open Space, Trails and Greenways for Wildlife and

People.

Chapter 6: Restoring the Hydrological Cycle in the

Urban Forest Ecosystem1

Lawrence V. Korhnak2

1. This is Chapter 6 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kämpf Binelli, and L.V. Korhnak, Eds.) produced

by the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Lawrence V. Korhnak, Senior Biological Scientist, School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University

of Florida, PO Box 110410, Gainesville, FL 32611

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Forests provide a protective cover for the

landscape and cycle much of the precipitation back to

the atmosphere. They are essential components of

many aquatic ecosystems. When native forests are

removed and replaced with impervious surfaces and

high maintenance vegetation, much of the water that

would have been returned to the atmosphere or

percolated into the ground water, washes off the

landscape. The quantity and energy of this runoff

erodes landscapes, deteriorates aquatic habitat, and

floods human habitat. In addition, the runoff washes

away chemicals that have been concentrated on the

land to support high maintenance vegetation.

Polluted runoff, referred to as non-point source

pollution, is our nation's most serious water quality

problem. Reestablishing the urban forest can help to

protect the landscape and associated aquatic

ecosystems. Runoff can be reduced, use of polluting

chemicals can be lowered, and aquatic habitat and

ecosystem links can be reestablished.

Forest Water Cycle

Forest Water Cycle Overview

On average, two-thirds of precipitation entering

U.S. forests is returned to the atmosphere through

evaporative processes. Most of the remainder

percolates through the porous forest soils to streams

or fills underground geological storage space. Forests

function as a protective layer and are a key link

between the atmosphere and the land in the water

cycle (Figure 1).

The forest canopy intercepts both the falling rain

and its kinetic energy. Some of the intercepted

rainfall is evaporated to the atmosphere while the

rest drips to the ground as through-fall or runs down

the trunk as stem-flow. Forest soils are generally

very porous so little through-fall washes over the soil

surface as runoff to water bodies. Instead, most of

the through-fall seeps or infiltrates into the soil. The

sun's energy evaporates water from inside the leaves

in the canopy in a process called transpiration.

Transpiration from the foliage creates a moisture

deficit that is transmitted as a suction force all the

way down to the tree roots. Much of the soil water is

sucked up by plant roots to replace the water

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 2

Figure 1. Forests are a key link in the cycle of water

between the atmosphere and the land.

transpired from the foliage. Depending on the soils,

geology, and other factors, some of the remaining

soil water will percolate deeper, and some will move

laterally into nearby streams.

Interception and Through-fall

Much of the rain falling on a forest landscape

will first impact the canopy vegetation (Figure 2).

Some will eventually drip to the ground and some

will be evaporated from the vegetation back to the

atmosphere. This evaporative loss is referred to as

interception loss. The percentage of rainfall

intercepted and evaporated by the forest canopy in

the U.S. ranges from about 12%-48% of rainfall

depending on the climate, tree type, and canopy

structure. For example, interception losses of 12%

were reported for mature hardwoods in the southern

Appalachian mountains (Kimmins, 1997), 18% for

pine flatwoods in Florida (Riekerk et al. 1995), 40%

for ponderosa pine in Arizona, and 43% for a

beachforest in New York (Kimmins 1997).

Figure 2. Much of the rain falling onto a forest landscape

will first impact the canopy vegetation. Some will

eventually drip to the ground, but on an annual average

12% to 48% will be evaporated from the vegetation back

to the atmosphere.

The kinetic energy of rainfall can cause

significant soil erosion (Figure 3). A one inch storm

will deliver about 2 million foot pounds per acre of

kinetic energy. Most of this energy can be adsorbed

by the forest canopy and forest litter. Without this

shield the rainfall energy will break up soil particles

into smaller more easily transportable materials.

Most of the splashed soil will move downhill. The

fine particles resulting from the rainfall breakup of

larger soil aggregates will clog soil drainage and

result in more runoff. This can result in sheet flow

and sheet erosion. This water energy will concentrate

in small depressions called rills, which over time may

develop into gullies. Left unchecked, erosion can

carve canyons (Figure 4).

One way researchers measure interception losses

is to measure rainfall inputs into the forest (either

above the canopy or in a nearby open area), and at

the same time measure through-fall with collection

devices (for example troughs and funnels) under the

canopy (Figure 5). Interception losses are the

difference between these two measurements.

Interception is related to canopy leaf area which can

be measured with leaf fall traps.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 3

Figure 3. The kinetic energy of rainfall can cause

significant soil erosion. A one inch storm will deliver about

2 million foot pounds per acre of kinetic energy. Much of

this energy can be adsorbed by the forest canopy. Photo

by Andrew Davidhazy, Rochester Institute of Technology,

School of Photographic Art and Sciences.

Figure 4. In Georgia at Providence Canyon State Park

you can observe the severe erosion that can result from

permanently removing the forest canopy from the

landscape.

Figure 5. Through-fall is measured with troughs and

funnels placed under the canopy. The measurements are

often correlated with canopy leaf area, which is estimated

in this figure with leaf fall traps.

Transpiration

Transpiration is the evaporation of water from

within living plant tissue. Solar energy creates a

water potential gradient by evaporating water

through leaf openings called stomata (Figure 6).

This gradient is transmitted to the roots where soil

water is absorbed and transported to the foliage via

the conductive network of xylem. Transpiration in

the continental US ranges from about 30%-60% of

precipitation and is a function of climate, vegetation

type, and stand structure (leaf area). A Florida pine

forest transpires almost a million gallons per acre in a

year (Riekerk et al.1995).

Figure 6. Energy from the sun evaporates water from

inside living plant tissue through openings called stomata.

The guard cells can open and close the opening and

provide some regulation of the process. Photo micrograph

courtesy of the Center for Microscopy and Micro Analysis.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 4

The "Transpiration Pump" also helps to draw

nutrients from the soil into the tree. Trees have been

described as "solar powered chemical machines that

mine the soil for minerals" (Figure 7). In addition to

sucking up water, trees also draw in their required

nutrients. For vigorously growing forests, trees will

uptake about 100 kg/ha/yr of Nitrogen and 15

kg/ha/yr of Phosphorus (Kimmins 1997).

Figure 7. With the aid of the "transpiration pump" trees

can remove significant amounts of nutrients from the soil.

Transpiration is difficult to measure, but two

methods are the sap flow gage and the leaf chamber.

Sap flow is measured by applying a known heat

source around the trunk of the tree and measuring the

heat energy that is removed by the sap flowing up the

trunk to replace transpired water (Figure 8).

Figure 8. A sap flow gage measures sap flowing up the

tree trunk on its way to be transpired from the leaves.

The leaf chamber is a small transparent chamber

that encloses the leaf and measures the moisture that

enters and exits the chamber (Figure 9). The positive

difference is transpired moisture. One major

difficulty of both these methods is scaling up the

measurements from individual trees and leaves to the

forest.

Figure 9. The leaf chamber measures water transpired

from foliage enclosed in the chamber. Scaling these

measurements up to the forest level is a challenge.

Evapotranspiration

The sun's energy will evaporate water from

many of the components of the forest ecosystem.

Often researchers will combine all the evaporative

losses into one measurement, called

Evapotranspiration (ET). Evapotranspiration

includes transpiration, interception evaporation, soil

evaporation, and water body surface evaporation

(Figure 10). In temperate forest regions about 70%

of the precipitation is returned to the atmosphere

through evapotranspiration (Hewlett 1982).

Infiltration

Infiltration is the movement of water from the

soil surface into the soil (percolation is the

movement of infiltrated water through the soil).

Generally, there is a lot of space between the soil

particles in forest soils and this allows water to easily

seep into the soil (Figure 11).

For coarse to medium textured forest soils, the

infiltration capacity is high and ranges from about 15

to 75 mm/hr (Brooks et al. 1991). Vegetation, both

in the canopy and on the forest floor, protect the soil

from compaction by rain energy. Forest floor

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 5

Figure 10. Evaporation is a term used for the sum of all

the evaporative water losses in a forest.

Figure 11. Water moves into the soil through both the

small spaces between soil particles and the larger spaces

between blocks of soil.

vegetation, both alive and dead, prevents rain splash

erosion from clogging soil pores with colloidal

material (Figure 12). In addition, forest floor

vegetation increases infiltration capacity by retarding

surface flow, thus giving water more time to sink in.

Raking the forest floor clean of vegetation, as is done

in many urban parks, will reduce the ability of the

forest to soak in rainfall and thus increase storm

water runoff. Roots and old root channels also make

the soil more pervious.

Figure 12. The live and dead vegetation on the forest floor

serve important functions in the infiltration process. Photo

by Ken Clark.

Runoff

Surface runoff in the forest landscape occurs

when the rainfall (or through-fall) intensity exceeds

the infiltration capacity of the soil and surface

storage is full. Forest soils generally have infiltration

capacities that exceed most rainfall events. So how

does storm flow occur in the forest? Precipitation

falling on the stream channel and saturated areas near

the stream are the source of most early storm flow.

As rain continues to fall, the saturated source area

expands due to direct precipitation and infiltration,

and from water infiltrating elsewhere and moving

down slope. This expanding saturated variable

source area contributes most of the storm flow to

forest streams (Figure 13).

Figure 13. An expanding saturated source area

contributes most of the storm flow to forest streams.

One method scientists use to answer questions

regarding the hydrological impacts of forest

management is with paired watershed experiments.

In this method the water outputs of similar drainage

basins are measured with hydrological structures like

flumes and weirs (Figure 14). Data are collected

from the watersheds for several years before

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 6

treatment in order to establish statistical

relationships. Then the treatment is applied to one of

the watersheds and the post treatment data is

analyzed to determine if the statistical relationship

changed in a significant way.

Figure 14. A weir is one type of structure used for

measuring forest stream flow. It is an important tool for

answering questions about the effects of land

management on the hydrological cycle. Photo by Hans

Riekerk.

Seepage and Groundwater

Much of the water infiltrating into the soil

supplies evapotranspiration demands. The remainder

will seep down (percolate) until it hits a permeability

barrier, for example clay or rock, and then will move

down laterally. Lateral seepage provides flow to

streams in dry weather (base flow). In more

permeable soils, seepage may move deeper down

into porous geological formations, called aquifers.

Depending on the geology, the groundwater may

remain stored in the aquifer for less than a week or

for over 10,000 years. In regions with dissolved

limestone geology (karst) groundwater will often

move down gradient in undergrounds rivers. When

these underground rivers intersect surface openings

they form springs. When they intersect openings in

the ocean floor they form blue holes. Occasionally

the pressure of the spring flow will force the water

above the ground surface to form fountain-like

artesian springs. Most of the earth's water is in the

oceans, but over 99% of the liquid water associated

with the land is groundwater. Groundwater is an

essential resource for drinking water (Figure 15). In

many areas of the country forest land is being bought

to protect ground water supplies from pollution

associated with other land uses. High quality

groundwater is also important for growing the food

we eat (Figure 16).

Figure 15. In much of the U.S. groundwater supplies

critically needed drinking water. This photo shows

groundwater returning to the surface as a spring and

some of its surrounding forested catchment area. Springs

keep many rivers flowing during periods of dry weather.

Figure 16. Good quality groundwater is also important for

irrigating and growing the food we need to eat.

Impacts of Urbanization on the Water

Cycle

Overview

Forests provide a protective cover for the

landscape and cycle much of the precipitation back to

the atmosphere. They are also essential components

of many aquatic ecosystems. When native forests are

removed and replaced with impervious surfaces and

high maintenance vegetation, water that would have

been returned to the atmosphere or percolated into

the groundwater, washes off the landscape (Figure

17).

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 7

Figure 17. The urban landscape distorts and shortens the

hydrological cycle.

The percent of runoff increases almost in direct

proportion to the impervious area. In addition,

impervious surfaces prevent storage of water in the

soil and urban activities often fill in natural water

storage areas like flood plains and wetlands. The

result is that increased amounts of water are

delivered to water bodies in a shorter period of time.

More water moving faster causes floods and erosion

that damage both life and habitat (Figure 18).

Figure 18. The replacement of forest with urban

impervious surface will degrade stream health. Source:

Schueler 1992.

Water washing over the urban landscape

transports nutrients and other chemicals into aquatic

ecosystems. This type of pollution is termed

"non-point source", and it is our nations most serious

water quality problem. Nutrients can stimulate algae

production to the point where the ecosystem is no

longer inhabitable by native organisms. Other

pollutants have toxic effects on aquatic organisms

and contaminate drinking water.

Forests are an integral component of many

aquatic ecosystems. They provide water temperature

moderation, support food webs, provide in-stream

habitat and stabilize stream banks. Breaking the

forest ecosystem-aquatic ecosystem link will

diminish the biological value of aquatic ecosystems.

Water Quantity Problems

Altering the Landscape Will Alter the

Hydrology

Disturbing a forested landscape with agricultural

and urban activities will alter the response of the

landscape to precipitation events. Forests retain and

evaporate most of the incoming precipitation

(Figure 19). The hydrograph (graph of discharge

over time) for the forest watershed reflects this lower

and more gradual release of water (Figure 20).

Figure 19. In the forest water cycle, most of the

precipitation is returned to the atmosphere and infiltrates

into the soil. Flow to streams is slowed and moderated by

the forest's complex structure.

In agricultural landscapes, heavy machines and

livestock compact the soil. Compacting squeezes the

soil particles closer together and reduces the soil pore

space. With less pore space, rainfall will not soak into

(infiltrate) the soil as well. A landscape with a

reduced infiltration capacity will produce more

runoff (Figure 21). The hydrograph will have a

higher peak and because more water travels the faster

surface route, the peak flow rate will occur earlier.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 8

Figure 20. Water from the forest is released in lower

amounts and more slowly compared to other land uses.

Source: Beaulac and Reckhow 1982.

Figure 21. In the agricultural landscape, soil compaction

results in less infiltration and increased runoff. Photo by

USDA.

In the urban landscape even more runoff will be

produced faster because the soil is often highly

compacted or covered with impervious surfaces

(Figure 22). Impervious area distorts the

hydrological cycle. Infiltration, storage, and

transpiration are reduced and runoff increases in

proportion to the percent impervious area (Figure

23). Urban impervious surfaces are designed to move

water quickly off site. More runoff and less delay of

runoff results in higher peak-flows and flooding.

Figures 24, 25, and 26 show generalized changes in

the water cycle resulting from different levels of

impervious area in urban landscapes (EPA 1993a).

Figure 22. In the urban landscape, impervious surfaces

produce more runoff in a shorter period of time.

Figure 23. When forests are replaced with impervious

surfaces, transpiration and infiltration are reduced and

runoff increases in proportion to the percent impervious

area. Source: Novotny and Olem 1994.

Figure 24. In low density residential areas with 10 to 20 %

impervious area, evapotranspiration and groundwater

account for most of the water loss.

The Importance of Storage

In the forest water cycle, precipitation is

captured and stored by the forest vegetation, forest

litter, and soils. If preconditions are dry and the

amount of rainfall is moderate, much of this water

will be temporally stored and returned to the

atmosphere through evaporative processes. Under

wetter conditions there is less storage, and more

rainfall may become stream flow. However, the

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 9

Figure 25. As the percent impervious area increases in

higher density residential area outputs to

evapotranspiration and groundwater are reduced and

surface water runoff increases.

Figure 26. Surface water predominates the water cycle in

commercial and industrial areas.

complex structure of the forest landscape creates a

tenuous path that delays the water's release from the

land. This delay will result in more gradual stream

inputs and a gentler rise in stream flow (Figure 27).

Figure 27. Storage of precipitation, in the forest canopy,

litter, soil, and wetlands, is important for reducing flood

hazards.

In urban systems, the storage capacity of

vegetation is reduced, soil compaction reduces soil

storage space and impervious surfaces prevent

rainfall from entering much of the soil altogether.

Often flood plains, wetlands and other depressional

storage sites are filled in, further reducing storage

(Figure 28). As a result, more water reaches the

stream in a shorter period of time.

Figure 28. In urban areas flood plains and wetlands are

often filled in reducing hydrological storage. In addition,

these areas near the water are often prime real-estate.

These factors combine to set up conditions for destructive

flooding events.

Flooding and Aquatic Habitat Degradation

Flooding and erosion resulting from altered

landscapes are serious concerns for human life and

property. They also impact aquatic organisms and

degrade their habitat. Impervious surfaces often form

an effective conveyance system for rapid transport of

runoff into urban water bodies such as streams. The

quantity of stream flow is equal to the cross sectional

area of the stream channel multiplied by the average

stream velocity. To convey the additional runoff

produced from disturbed landscapes, the cross

sectional area of the stream and/or the stream

velocity must increase. Streams increase their cross

sectional area by rising up their banks, and many

have natural flood plains for conveying runoff from

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 10

extreme precipitation events. In the urban landscape,

the flood plain may be filled in and built in, and

flooding will occur (Figure 29).

Figure 29. Reduced storage, high runoff rates, and

concentrated peak flows will often result in flooding in

urban landscapes.

The energy of water increases exponentially as

its velocity increases. High energy urban stormwater

runoff scours stream bottoms, and erodes and

undercuts their banks (Figure 30). Stream side

vegetation and aquatic habitat are washed away and

conditions are set for destructive landslides.

Figure 30. High energy urban stormwater runoff scours

stream bottoms, erodes and undercuts their banks. This

degrades aquatic habitat and creates dangerous landslide

conditions.

Water Quality Problems

Non-Point Source Pollution

Increased runoff is not the only concern when

the forested landscape is altered. Generally, forest

ecosystems require little if any extraneous inputs of

chemicals and disturbance is infrequent. On the other

hand, to sustain agricultural and urban activities,

nutrients, pesticides, herbicides, and energy

producing chemicals are concentrated on the

landscape. Urban impervious surfaces are associated

with intensive land uses that generate pollution. They

function as an efficient conveyance system for

transporting pollutants directly to aquatic

ecosystems, bypassing the pollutant removal

functions of the soil (Figure 31).

Figure 31. Roads often function as an efficient system for

transporting pollutants to aquatic ecosystems.

Soil disturbance is frequent in agricultural and

urban watersheds. Construction in urban watersheds

removes the protective vegetative cover and erosion

can produce 10 to 100 times more sediment than

natural areas (up to 50,000 ton/km2/yr) (Novotny

and Olem 1994) (Figure 32).

Figure 32. Pollution washed from altered landscapes is

referred to as non-point source pollution. This aerial photo

shows a sediment plume in a lake washed from upstream

construction in an urban watershed. Photo by Hans

Riekerk.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 11

Stormwater generated from urbanized

landscapes will wash pollutants into aquatic

ecosystems, often causing severe dysfunction

(Figure 33). This type of diffuse pollution is called

non-point source pollution. In contrast, point source

pollution originates from focused sources such as the

effluent from waste water treatment plants (Figure

34).

Figure 33. Stormwater runoff will wash many pollutants off

urban impervious surfaces into aquatic ecosystems.

Figure 34. Point source pollution often originates from

waste water treatment plants and factories whose

discharges are emitted at discrete, identifiable locations

such as pipes and ditches.

Much progress has been made in cleaning up

point source pollution, but treating non-point source

pollution problems are generally more difficult and

costly. Non-point source pollution is responsible for

the majority of the impaired use of our nations

waters. Of the total pollution load to our nations

waters, non-point sources contribute 90% of

nitrogen, 90% of the fecal coliform bacteria, 70% of

the oxygen demand, 70% of the oil, 70% of the zinc,

66% of the phosphorus, 57 % of the lead, and 50% of

the chromium (Thompson et al. 1989).

Measurement of Non-Point Source

Pollution

Different land uses have been measured to

export different amounts of substances (Figure 35).

Activities that increase runoff (such as soil

compaction and paving), and activities that expose

pollutants to washing off the land (such as over

fertilization), will contribute to higher export rates.

The exports are usually measured in kilograms

leaving the land area (per hectare) for a year. These

values are determined by measuring the quantity and

quality of water leaving a known area of drainage

basin.

Figure 35. The forest landscape exports much less

pollutants than more intensive land uses.

Typically, the first step in measuring the

amount of water leaving a land area is to develop a

stream height-discharge relationship (rating

equation) for a stable section of the stream channel.

On smaller streams the stream cross section is often

modified into a more hydraulically uniform shape by

a flume (Figure 36) or weir (Figure 37).

Discharge is the product of cross sectional area

of the stream channel multiplied by the average

stream velocity. Depth measurements are taken along

the cross section to calculate the area and velocity

measurements are taken at different depths at

different locations to determine the average velocity.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 12

Figure 36. Flumes are flow modification structures

designed to accurately measure the amount of water

passing through them. They are self cleaning and can

work with relatively low head loss, but they are very

expensive.

Figure 37. Weirs also measure flow, and they are less

expensive than flumes. However, they dam up the water

behind them which can cause many problems.

This process is repeated for a wide range of flow

conditions and the data are used to construct an

equation that will estimate stream flow from stream

height. These equations have been determined under

lab conditions for weirs and flumes, but real world

conditions will modify their flow characteristics, so

on-site calibration is good practice.

Flow proportional sampling is required for an

accurate determination of the amount of substance

(for example nitrogen or phosphorus) passing

through the measurement station. This is

accomplished by a microcomputer that reads the

stream stage, calculates a flow from the rating

equation, and activates an automated sampler to take

a water sample when the specified volume of water

has passed through the measurement section.

Here is a simple hypothetical export calculation.

From a topographic map and an inspection of the

watershed, the contributing area to a stream gaging

station was determined to be 10 ha. The total water

passing through the measurement channel for a year

was 10,000 m3. The average total nitrogen

concentration of the volume weighted samples was

5,000 mg/m3. The mass of nitrogen is calculated by

multiplying the flow volume by the concentration.

For this example:

10,000 m3 x 5,000 mg/m3 = 50,000,000 mg or

50 kg of nitrogen. Thus the land export was 50 kg/10

ha/yr or 5 kg/ha/yr.

From the perspective of the receiving water

body, for example an urban lake, the land export is

referred to as a load. The loading rates of the

nutrients nitrogen and phosphorus into water bodies

are one of the crucial factors that determine their

biological and physical conditions. Proposed changes

in land use in a lake's watershed can be used to

predict the change in nutrient loads and the probable

biological and physical impacts to the lake. Export

and load information are used to guide watershed

restoration efforts.

Eutrophication

Nutrient loading of aquatic ecosystems causes

eutrophication or nutrient enrichment. Symptoms of

eutrophication may include decreased water clarity,

algal blooms, nuisance growth of macrophytes,

unpleasant taste and order, dissolved oxygen

depletion, fish kills, and altered species diversity and

richness (Figure 38) (National Academy of Sciences

1969).

Nutrients in urban storm water runoff are the

leading source of impairment of our nation's

estuaries (EPA 1996). Developmental stresses pose a

serious threat to the health of these productive and

complex ecosystems (Figure 39). By the year 2010

almost half of the U.S. population will live near

coastal waters, and the population of many coastal

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 13

Figure 38. Nutrients washed from high maintenance urban

landscaping may stimulate algae growth and distort

system ecology. In severe cases the resulting

environmental changes will make the ecosystem

uninhabitable to native species.

cities is predicted to triple in the next 15 years (EPA

1996). Nutrients imported into estuarine watersheds

to sustain high maintenance landscapes are washing

into the estuaries and disrupting ecological

relationships. For example nitrogen from fertilizers

can stimulate dense growth of algae that will shade

out sea grass. Sea grass is critical spawning and

nursery habitat for much of our seafood (Figure 40).

Figure 39. Increasing development in our coastal areas

will result in more storm water runoff making an already

serious problem worse.

Figure 40. Fertilizers in storm water runoff can destroy

critical habitat for many of the species that provide us

delicious seafood. Photo Philip by Greenspun, M.I.T.

Nutrients are essential for the existence of both

terrestrial and aquatic ecosystems but the level of

nutrients will play a major role in determining the

character of the ecosystem. When urban storm water

washes excess nutrients into an aquatic ecosystem,

the nature of the ecosystem will change. This human

influenced process of nutrient enrichment of aquatic

ecosystems is called cultural eutrophication. In

severe cases the resulting environmental changes

may make the ecosystem uninhabitable to native

species.

Most often the root of the problem is excessive

inputs of the critical plant nutrients, nitrogen and

phosphorus. When one or both of these nutrients

limit plant growth, additional inputs will stimulate

aquatic weed and algae growth. The aquatic plant

community often provides the primary source of

organic carbon energy and forms the foundation of

the ecosystem. Changes in this critical component of

the ecosystem will have system wide impacts.

Often the impacts are undesirable. Algal blooms

will decrease water clarity. This lowers the

recreational and aesthetic value of the water body. If

the water body is an important drinking water

supply, algal blooms may impart a bad taste and odor

to the water and clog treatment systems. In addition,

dense algal blooms will shade out submerged aquatic

plants. These aquatic plants are important breeding

and nursery grounds for many sport and food fish.

Conditions in highly nutrient rich water bodies favor

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 14

filter and bottom feeding fish. These will multiply to

the detriment of many other species and reduce the

species diversity of the ecosystem. Aquatic

ecosystems, especially shallow ones and those with

low flushing rates, tend to keep and recycle the

nutrients they obtain. Therefore, it is difficult and

expensive to restore many impacted water bodies.

Oxygen

Urban storm water can reduce dissolved oxygen

levels in aquatic ecosystems by reducing the

dissolved oxygen holding capacity, by stimulating

algae respiration with nutrients, and by stimulating

microbial respiration with organic carbon sources

(Figure 41).

Figure 41. Urban storm water can reduce dissolved

oxygen levels in aquatic ecosystems by reducing the

dissolved oxygen holding capacity, by stimulating algae

respiration with nutrients, and by stimulating microbial

respiration with organic carbon sources.

The oxygen holding capacity of water is a

function of the water temperature. Specifically,

colder water can contain more oxygen than warmer

water. For example, water at 3 degrees C can contain

13 mg/l of dissolved oxygen while water at 35

degrees C will only hold 7 mg/l of dissolved oxygen.

In an urban system, water from heated buildings, hot

streets and roofs can raise the temperature of water

bodies. Removal of trees that shade urban streams

will also raise water temperatures. To compound the

problem, elevated water temperatures will often

increase the metabolic rate of cold blooded aquatic

organisms, thus increasing their need for oxygen.

Nutrients, especially phosphorus and nitrogen,

can stimulate increases in algae populations. When

there is adequate sunlight and inorganic carbon,

algae will produce large amounts of oxygen during

photosynthesis. In fact, oxygen levels may actually

climb above saturated levels in a system with high

densities of algae during bright sunlight. However, at

night or during extended cloudy periods, the algae

will remove large amounts of oxygen from the water

for their metabolic needs. Under extreme conditions,

the algae can deplete the dissolved oxygen supply

and fish kills will occur (Figure 42). This is most

common under conditions where diffusion of oxygen

from the atmosphere into the water is impaired, such

as when the water is covered with ice or when the

water column is prevented from mixing due to

thermal stratification.

Figure 42. Under certain conditions, high levels of algae

can deplete oxygen in water resulting in fish kills.

Algae and fish are not the only competitors for

dissolved oxygen in aquatic ecosystems. Aquatic

bacteria will feed on organic materials washed into

water bodies. They convert oxygen into carbon

dioxide in a biochemical process similar to our

metabolism of food. When large amounts of organic

materials are washed into a water body, bacterial

growth and metabolism can be stimulated to the

point that their consumption of oxygen will exceed

system inputs. For many bacteria, when the oxygen

is used up they can make use of alternate oxidants

such as nitrate, and oxidized forms of manganese,

iron, and sulfur. Unfortunately, many higher level

aquatic organisms are dependent on dissolved

oxygen, and when it is depleted they will die. Also

certain chemicals, for example ammonium, will

combine with dissolved oxygen and make it

unavailable. The oxygen depleting properties of

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 15

pollution are often measured as Biochemical Oxygen

Demand or BOD. BOD is determined by measuring

the oxygen loss of a water sample in a sealed bottle

kept in the dark for five days.

Aquatic Habitat Alteration

Even if urbanization had no impact on water

quality and quantity, there are often other severe

impacts on aquatic life. In many urban areas the

physical structure of aquatic habitats are modified

for municipal functions to the detriment of biological

functions. Trees removed from stream banks expose

the stream to less moderated temperature conditions

(higher in the summer, colder in the winter) (Figure

43).

Figure 43. In a forested stream, trees moderate water

temperatures, support food webs, provide stream habitat

and stabilize the banks.

Removing trees also removes an important

source of fuel for detrital food webs. During

urbanization, stream channels are straightened, large

woody debris removed, and even the bottom

substrate may be covered with pavement (Figure

44). These types of modifications remove critical

stream habitat and sterilize the aquatic ecosystem's

ability to support aquatic life. In extreme cases,

urban streams are "blacked out" by enclosing them in

pipes and covering them up.

Figure 44. In many urban streams the forest has been

removed and the aquatic ecosystems that they supported

can not exist. Photo by Judy Okay

Restoration

Overview

Restoring the urban forest can help to restore the

hydrological cycle and improve the functioning of

aquatic ecosystems. Significantly increasing tree

canopy coverage will reduce stormwater runoff and

peak flow, and increase the water storage capacity.

Urban forests are particularly critical near creeks,

streams, and rivers, where they act as riparian forest

buffers (Figure 45).

Forested riparian areas stabilize banks, uptake

nutrients, and provide shade, habitat, and food for

aquatic ecosystems. The magnitude of chemicals

used to support high maintenance urban landscapes is

overwhelming our efforts to treat polluted runoff.

Programs that encourage landscaping with native

forest trees can help because these trees will often

require less inputs of chemicals and water.

Urbanization alters and fragments aquatic

ecosystems, sometimes so severely that they cease to

function. More environmentally orientated planning

can prevent the problem, and reforestation is often

the key element in restoring the system.

Increasing Tree Coverage

Increasing or preserving tree coverage in an

urban watershed can have water quantity and quality

benefits. However, the scale of the restoration effort

needs to match the scale of the problem. A small

urban park, even one with a big tree will do little to

restore the water cycle to a big city (Figure 46).

Larger scale efforts are usually needed. Storm water

modeling with CITYgreen© software (American

Forests 1996) demonstrates the scale of coverage

needed with its expected water quantity benefits

(Figure 47).

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 16

Figure 45. Urban forests are particularity critical near

creeks, streams, and rivers, where they act as riparian

forest buffers. Forested riparian areas stabilize banks,

uptake nutrients, and provide shade, habitat, and food for

aquatic ecosystems.

Figure 46. Increasing or preserving tree coverage in an

urban watershed can have water quantity and quality

benefits. However, the scale of the restoration effort needs

to match the scale of the problem.

Figure 47. Computer models such as CITYgreen©

software (American Forests 1996) can demonstrate the

value of the ecological services that trees provide.

Illustrations from CITYgreen Their model predicts increasing tree coverage on

an example residential development will reduce

storm water runoff and save money. With a 30% tree

cover the model predicts a 5 % decrease in runoff

volume, a 9 % decrease in peak flow and a 15 acre

feet/square mile increase in water storage. Potential

storm water storage treatment savings were

estimated to be about $120,000/square mile. When

the tree canopy coverage is increased to 70%, the

model predicts a 17 % decrease in runoff volume, a

27 % decrease in peak flow and a 48 acre feet/square

mile increase in storage. Potential storm water

storage treatment savings were estimated to be about

$390,000/square mile.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 17

There are some issues that must be considered

when evaluating the water quantity and quality

benefits of tree cover. The first is the timing of

benefits. Storm water engineers must design new

developments so that they meet hydrological

specifications for the first storm, not how the

development will respond many years later when the

canopy has grown to significant coverage. The

development must also continue to meet

hydrological specifications in winter when deciduous

trees have lost their cover. Storm water engineers

also know that canopy storage will be quickly filled

by the large storms that cause flooding events.

However, canopy storage can reduce the runoff of

the frequent smaller storms, and thus has the

potential to reduce pollutant loading to aquatic

ecosystems.

Riparian Forest Buffers

Riparian forest buffers have the potential to

reduce the amount of runoff and pollutants washing

into riparian ecosystems. They also stabilize stream

banks and moderate water temperatures. Preserving

or restoring forested riparian buffers also preserves

some of their ecological functions such as providing

terrestrial and aquatic habitats, and supplying the

source for detrital food webs. Many forested riparian

areas also contain flood plains and wetlands that

provide additional water quantity and quality

benefits. Forested riparian buffers are aesthetically

beautiful areas and can provide some forms of low

impact recreation.

There are three functional zones comprising a

well designed forested riparian buffer (Figure 48).

Zone 3 is a flat grassy area about 10m wide at the

urban-buffer interface (Figure 49). Its major

function is to convert channelized urban flow into

sheet flow and slow water velocity to less than 0.3

m/sec. Zone 3 performs some settling, filtering, and

infiltration.

Figure 48. There are three functional zones comprising a

well designed forested riparian buffer. The zones are

designed to spread out and infiltrate storm water,

assimilate nutrients, and preserve the aquatic habitat.

Figure 49. Zone 3 is a flat grassy area about 10m wide at

the urban/buffer interface. Its major function is to convert

channelized urban flow into sheet flow and slow water

velocity to less than 0.3 m/sec. Zone 3 performs some

settling, filtering, and infiltration. Photos are of the

"Difficult Run" urban riparian project, courtesy of Judy

Okay, Virginia Department of Forestry.

Zone 2 is a vigorously growing forest with a

width of 15 to 150m (Figure 50). The required width

depends on the load amount and the buffer slope,

soils, vegetation and level of allowed disturbance.

The major function of Zone 2 is to provide the

environment and contact time (at least 9 minutes) for

pollutant removal through sedimentation, filtration,

cation exchange, and plant uptake. In forest and

agricultural situations, selective removal of trees

from Zone 2 is recommended. Tree removal removes

nutrients and keeps the forest in a vigorous growth

stage.

Zone 1 is the mature forest at the land-water

interface and it controls the physical, chemical, and

trophic status of the stream (Figure 51). Zone 1

should be at least 10m wide. The major water quality

functions of Zone 1 are to stabilize the stream bank

and to shade and stabilize water temperatures.

Anoxic (without oxygen) organic soils in this zone

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 18

Figure 50. This photo was taken down slope from Figure

49 and shows the establishment of a zone 2 managed

forest. The left side is at planting and the right side is three

years after planting. Photo by Judy Okay, Virginia

Department of Forestry.

can remove nitrogen by the process of

denitrification, but uptake of other nutrients may be

balanced by litter fall. Zone 1 also provides detritus

for the aquatic food web and large woody debris for

critical aquatic habitat.

Figure 51. Zone 1 is the mature forest at the land/water

interface. It most directly controls the physical, chemical,

and trophic status of the stream. Photo by Judy Okay,

Virginia Department of Forestry.

Forested riparian buffers have their limits

(Herson-Jones et al. 1995). Pollutant removal

effectiveness is poor when the slopes are greater than

10% and with soils that have infiltration rates less

than 0.64 cm/hour. Disturbance (many recreational

activities) will greatly reduce their effectiveness. The

scale of the buffer needs to match the scale of the

source area. Poor performance can be expected with

high rates of channelized flow from large impervious

areas. Upstream Best Management Practices (BMPs)

may be required to scale the load to match the

buffer's capacity. Even under good conditions total

suspended solid removal is estimated to be 50%.

Source Control

The United States has 30 million acres of lawn.

On these lawns over 100 million tons of fertilizer

and 80 million pounds of pesticides are applied

annually (Borman et al. 1993) (Figure 52). This rate

of application is ten times the rate chemicals are used

per acre on US farms. The importation and

concentration of chemicals in urban watersheds

saturates and overwhelms our efforts to treat polluted

non-point source runoff. In an effort to reduce

harmful impacts to our aquatic ecosystems, many

new programs are focused on reducing the sources of

non-point pollution. These programs encourage

landscaping that uses and exports less water and

chemicals. Some examples of these types of

programs are BayScaping in the Chesapeake Bay

area (http://www.acb-online.org/bayscapes.htm),

Nature Scaping in the Portland, Oregon area

(http://www.enviro.ci.portland.or.us/ ), Florida

Yards and Neighbors

(http://207.0.223.151/extension_service/toc.htm),

and EPA's Green Communities

(http://www.epa.gov/greenacres/).

Figure 52. Over 100 million tons of fertilizer and 80 million

pounds of pesticides are applied annually to U.S. lawns.

The general strategy of these programs is to

encourage landscaping that uses less pollutants and

produces less runoff. Native vegetation and ground

covers are recommended because they generally

require less inputs of water and chemicals (Figure

53). In addition, exotic landscaping vegetation can

escape and cause hydrological and other ecosystem

problems (Figures 54 and 55) (See Chapter

9-Invasive Plants).

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 19

Figure 53. This is an example of a yard that uses native

trees and low maintenance ground cover. Native trees are

often adapted to local conditions and require less

supplemental inputs of water, fertilizer, and pesticides. In

this example the trees also provide pine needles for an

attractive and low maintenance ground cover.

Figure 54. Exotic landscape plants can require more

water and chemicals and contribute to urban water

pollution. In addition, they can invade and damage natural

ecosystems. The Salt Cedar (Tamarix sp.) shown on the

right in the above photo (Zion National Park) has invaded

much of the Southwest altering hydrology and displacing

native plants.

Figure 55. Salt Cedar has roots that can reach depths of

30 meters and individual trees can use 800 liters of water

per day. Large stands of Salt Cedar can lower the ground

water below the level that native vegetation can reach.

They also adsorb salts from deeper soil layers and ground

water and transport it to their leaves (see above photo).

This salt increases the soil salinity above levels that many

native plants can tolerate.

The reduction of impervious surfaces by using

gravel driveways (Figure 56) and on-site retention

landscaping (Figure 57) are examples of practices

that will reduce the export of water and pollutants.

Figure 56. Reducing the impervious surfaces at a home

by having an attractive gravel driveway instead of an

impervious paved one, will significantly reduce the

amount of water and pollutants that runoff property. The

cumulative impact of many citizens reducing their pollutant

load can make the restoration of aquatic ecosystems

possible.

Aquatic Habitat Improvement

The impact of urbanization on aquatic

ecosystems goes beyond the damage caused by

increased runoff and poor water quality. Frequently,

urbanization degrades the physical aquatic habitat by

altering its morphology, changing or even paving the

bottom substrate, and altering light inputs. Intakes for

domestic water supplies and dams will drastically

disrupt stream continuity. Aquatic systems are parts

of larger ecosystems. Poor urban planning can break

links to other systems that provide essential

functions to aquatic systems. For example, filling in

wetlands and flood plains can eliminate breeding and

nursery habitat, and removing upland forests

eliminates an important source of energy for detrital

food webs. Conversely, forested aquatic ecosystems

provide essential elements for upland ecosystems and

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 20

Figure 57. Large stormwater treatment facilities often

have poor pollutant reduction performance. A better

solution is to keep stormwater on site and allow it to be

filtered by the soil. This picture shows a "rain garden"

where runoff from the roof and driveway will be retained

and pollutants filtered out by the soil. Photo by Judy Okay,

Virginia Department of Forestry.

they often function as crucial corridors necessary for

the survival of many species.

Figure 58 shows an urbanized stream that would

not function with even the best water quality. Stream

morphology has been drastically altered, the bottom

substrate paved over, and stream-side communities

have been eliminated.

Figure 58. Even with the best of water quality this

urbanized stream will be a non-functioning ecosystem.

The stream morphology has been altered, the bottom

substrate paved over, and stream communities have been

eliminated.

In Figure 59 important stream habitat has been

restored by importing large woody debris directly

into the stream. Large woody debris provides

important nesting, cover and substrate for aquatic

life. Stream vegetation has been replanted to provide

shade for cooler and more stabilized water

temperatures and to provide detritus for food webs.

Figure 59. In this stream, important habitat has been

restored by importing large woody debris directly into the

stream. Large woody debris provides important nesting,

cover, and substrate for aquatic life. Streamside

vegetation has been replanted to provide shade for cooler

and more stabilized water temperatures, and to provide

detritus for food webs.

Engineering is necessary for a city to function

properly. Many cities are discovering that with a little

extra care, engineering functions can be combined

with ecological principles to provide functioning

aquatic habitats. For example, retention ponds are

used in urban areas to provide storage for increased

runoff and to settle out particulate pollutants.

Although the pond in Figure 60 may perform some

of those functions, it provides little if any aquatic

habitat. On the other hand, the detention pond in

Figure 61 incorporated wetlands and forests to

provide ecological functions as well as engineered

treatment of urban storm water.

Figure 60. Retention ponds are used in urban areas to

provide storage for increased runoff and to settle out

particulate pollutants. Although this pond may perform

some of those functions, it provides little if any aquatic

ecosystem habitat.

Urban parks also provide an opportunity for

aquatic habitat restoration or preservation. Often

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 21

Figure 61. On the other hand this pond was designed to

be a functioning ecosystem.

urban parks contain a significant amount of

impervious area and high maintenance vegetation

that can cause degradation of associated aquatic

habitat (Figure 62). With careful design forested

urban parks can provide recreational opportunities as

well as a functional aquatic habitat (Figure 63) .

Figure 62. Figures 62 and 63 are parks in Mt. Dora,

Florida. Although this traditional urban park provides

needed recreation activities, the natural habitat has been

paved or grassed, and the water features only provide

limited aesthetic value.

Figure 63. Nearby Palm Island Park, also at Mt. Dora,

Florida, has been left as an intact ecosystem. A board walk

allows people to explore the upland/wetland/aquatic

wonders with little negative impact to the hydrological

cycle and the ecosystems dependent on it.

References

American Forests. 1996. CITYgreen© Urban

Ecosystem Analysis Software. American Forests.

Washington, DC.

Beaulac, M. N. and K. H. Reckhow. 1982. An

examination of land use-nutrient export relationships.

Water Resources Bulletin. 18:1013-1023.

Bormann, F. H., D. Balmori, and G. T. Geballe.

1993. Redesigning the American lawn. Yale

University Press.

Brooks, K. N., P. F. Folliott, H. M. Gregerson, J.

L. Thames. 1991. Hydrology and the management

of watersheds. Iowa State University Press, Ames.

392 pp.

Environmental Protection Agency. 1993a.

Guidance specifying management measures for

sources of nonpoint source pollution in coastal

waters. USEPA #840-B-92-002. Washington, DC.

Environmental Protection Agency. 1993b.

Nonpoint Pointers. USEPA #EPA-841-F-96-004,

Washington, D.C.

Herson-Jones, L. M., M. Hertaty, and B. Jordan.

1995. Riparian buffer strategies for urban

watersheds. Metropolitan Washington Council of

Governments Environmental Land Planning Series

No. 95703. 101 pp.

Hewlett, J. D. 1982. Principles of forest

hydrology. The University of Georgia Press, Athens.

183 pp.

Kimmins, J .P. 1997. Forest Ecology: A

foundation for sustainable management. Printice

Hall, Upper Saddle River, New Jersey. 596 pp.

National Academy of Sciences. 1969.

Eutrophication: Causes, Consequences, Correctives.

Chapter 6: Restoring the Hydrological Cycle in the Urban Forest Ecosystem 22

Proceedings of a Symposium, National Academy of

Sciences, Washington, D.C.

Novotny, V., H. Olem. 1994. Water Quality:

Prevention, Identification, and management of

diffuse pollution. Van Nostrand Reinhold, New

York. 1054 pp.

Riekerk, H., H. L. Gholz, D. G. Neary, L. V.

Korhnak, and S. G. Liu. 1995. Evapotranspiration of

pineflatwoods in Florida. Finial Report to USDA

Forest Service Southern Forest Experiment Station.

37 pp.

Schueler, T. R. 1992. Mitigating the adverse

impacts of urbanization on streams: A

comprehensive strategy for local government. In: P.

Kumble and T. Schueler (eds). Watershed

Restoration Source book: Collected Papers Presented

at the Conference; Restoring Our Home River: Water

Quality and Habitat in the Anacostia. Publication

#92701 of the Metropolitan Washington Council of

Governments, Washington, DC.

Shahane, A. N. 1982. Estimation of pre and post

non-point water quality loadings. Water Resources

Bulletin. 18:231-237.

Thompson, P., R. Adler, and J. Landman. 1989.

Poison Runoff. National Resource Defense Council.

Washington, D.C. 484 pp.

Welsch D. J. 1991. Riparian forest buffers:

Function and design for protection and enhancement

of water resources. USDA Forest Service

Northeastern Area Document NA-PR-07-91. 23 pp.

Chapter 7: Site Assessment and Soil Improvement1

Kim D. Coder2

1. This is Chapter 7 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Kim D. Coder, Professor, University of Georgia, School of Forest Resources, Athens, GA 30602-4356. http://www.forestry.uga.edu/efr

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

The first step in any restoration project is to gain

an appreciation of the site. The site needs to be

defined, delineated, inventoried, and assessed for the

restoration goals and objectives to be successfully

accomplished. A key component in assessing sites

for ecological restoration is developing, both for your

own reference and others, a story of site development

or a site picture. This is called determining the site

context. Each site should be assessed for its

ecological and societal context. An ecological

management unit (EMU), the smallest treatable unit

-- smallest restorable unit -- must be the focus for

restoration management activities. Through the

assessment process, the primary concern is the

ecological restoration of the EMU. An initial site

assessment should include inventory of resources,

space, size, diversity, temporal changes,

disturbances, stress, natural cycles, organic matter,

management, form, and development of a final

action-list. However, it is just as important to the

success of any restoration project to include the stake

holders, decision-makers and social systems in all

phases of the project. Assessment is a part of the

planning and management process, not a disjunct and

separate piece. Remember that every site and

situation will be different.

Another decisive step to be considered in a

restoration project is soil health evaluation and

improvement. Soil health management is essential

for (and a part of) healthy and sustainable ecological

systems. A number of soil features become degraded

or destroyed over time in highly stressed

environments. An average urban soil usually has few

essential elements, poor drainage, erosion, soil

compaction, a heavy texture, little organic matter, and

a low diversity and small number of beneficial

organisms. Restoration activities need to be

prescribed carefully in trophic level order to assure

success -- in other words, truly start at the bottom

and restore upward. The soil is the foundation upon

which we restore ecosystem functions and structures.

The soil attributes to be restored successfully include

texture, structure, bulk density, water, aeration,

element holding capacity, essential elements, organic

matter, contamination, and trophic enrichment.

Introduction

The urban forest is the tie which binds humans to

life sustaining ecological systems. Beyond the urban

forest are the rocky and barren hardscapes of paved

and roofed deserts. We have interspersed these

buildings and roads with a few parks and road-side

trees which are often maintained with too many

resources and much energy. It is time to take back a

Chapter 7: Site Assessment and Soil Improvement 2

heritage of forest and field, and live more gently

among the trees. Restoration of these altered and

often exhausted ecological systems will not be quick

or easy. Yet the results and rewards are important to

the future health of our cities and communities.

A restoration process includes an understanding

of basic rules and perceptions regarding a

community's ecological resources and how to plan

and make decisions which impact these resources.

Other chapters in this CD-ROM review the

ecological principles and processes as well as the

development of a management plan. However, one

of the first steps in the restoration process is

assessing the site's resources. The soil is probably

one of the most damaged parts of the ecosystem in

the urban forest, therefore, restoring soil health of a

site is a critical step to successful restoration. The

first part of this chapter, Site Assessment, is

concerned with the steps involved in this assessment.

The second part of this chapter, Soil Improvement,

presents the principles of soil health and methods for

its restoration.

Site Assessment

Every surface and space in the urban forest is a

resource containing site. Most sites are severely

lacking in many resources, either through a lack of

quantity or quality. Many sites have experienced

disturbances such as hydrological alterations,

invasion of exotic species, compaction from

recreational activities and fragmentation. In

restoring these sites, urban foresters seek to restore

resources and processes. The first step in any

restoration project is to gain an appreciation of the

site. The site needs to be defined, delineated,

inventoried, and assessed even before the goals and

objectives for restoration are developed. Having a

clear picture of the site is essential to describe and

defend restoration options and plans to peers,

stake-holders, decision-makers, site workers, and

resource owners/controllers (Figure 1).

Figure 1.1 Photo by Mary Duryea

Figure 1.2 Photo by Larry Korhnak

Figure 1. Having a clear picture of the site is essential to

describe and defend restoration options and plans to

peers, stake-holders, decision-makers, site workers, and

resource owners/controllers.

Site components include:

• life resources

• life connections,

• biological units,

• climate,

• topography,

• geology, and

• past history (disturbances, stresses, and

mechanical damage).

What were the past historic ecosystems like on

the site? Using maps, interviews, GIS and other

resources, the historic ecosystems on the site need to

be described with their flora and fauna and natural

disturbances. Then the current ecosystems need to

be described; what is there now and why? And

finally how does this site fit into the landscape and

the master plan for the region? Does it have regional

Chapter 7: Site Assessment and Soil Improvement 3

significance, ecological significance, and/or social

significance (Figure 2)?

Figure 2.1 Photo by Mary Duryea

Figure 2.2 Photo by Larry Korhnak

Figure 2. Maps, GIS and other resources can be useful

tools for assessing past and current site conditions in a

restoration project.

Site Context

A key component in assessing sites for

ecological restoration is developing, both for your

own reference and others, a story of site development

or a site picture. This is called determining the site

context. How did the site arrive at its current

condition? Included in this assessment is

determining what it was like in the past. And finally

an evaluation of the possibilities for restoration.

Developing a full description of the site, its attributes

and processes, is critical for identifying the

possibilities and constraints to restoration.

Practically speaking, a restoration site might be a

perfect biological or ecological candidate, but

socially unacceptable for restoration. Each site

should be assessed for its ecological and societal

context.

The ecological story of a site must be

determined in any assessment process. The

ecological context of a site includes, but is not limited

to:

Anthropogenic changes to the ecosystems on

the site.

Site history (biological, physical, chemical),

including presence of toxins, hydrological

alterations, substrate changes such as impervious

layers, soil interfaces, and past abuse.

Soils, including fill, compaction, interface

problems, depth, drainage, aeration,

contamination, and flooding regimes.

Topography/slope, including cold pockets, soil

depth, water relations, and wind impacts.

Energy balance, including incoming radiation

and its distribution/dissipation, urban heat island

effects, wind and direction, light quality and

quantity, and night lighting.

Water balance, including relative humidity,

precipitation, evaporation, irrigation, and site

water demand.

Biological components (animals, plants,

microbes, etc.) and their interactions, including

pests, competition, allelopathy, disturbance,

succession, and mechanical damage.

Genetics, including cultivars, natives, exotics,

and genetic interactions with the environment

(response to stress, strain, abuse, and pests).

Space, including space for growth, expansion,

crowding, stagnation, and space to structurally

support life-forms.

Climate, including precipitation, temperature,

wind, pollution deposition, wind/pest

interactions, variability (winter to summer or

Chapter 7: Site Assessment and Soil Improvement 4

day to night), drought concerns in summer and

winter, lag effect (e.g., time delay) of symptom

expression, and problems of scale.

Climate is a critical feature of the site to

understand. In general, urban climates (local to

meso-climate scales) are significantly different than

average climate data collected at regional weather

stations. Urban climates, when compared to national/

regional averages, have: 25% lower wind speeds

from obstructions; 12% greater calm days (air mass

stagnation); 1.5 degrees F greater annual

temperature; 2.7 degrees F greater minimum winter

temperature; 7% greater precipitation events (more

precipitation events but less per event); 5% lower

relative humidity (geometrically increased site

water demands); 7% greater cloudiness; 17% less

incoming radiation (clouds and pollution); and, 10

times more common pollutants (Craul 1992). For

further information check Craul's urban soils books

listed in the Suggested Readings section.

In general, the urban climate is drier and hotter,

with less usable water, more pests, and more

pollution than normal. All these climate factors

combined lead to greatly increased stress on

ecosystems.

The societal context or story of a site must be

determined in any assessment process. The societal

context of a site includes, but is not limited to:

Anthropogenic changes of management, such

as changes in ownership from private to public

with different management goals, objectives and

implementation.

Historical significance, including

archaeological importance as well as more

recent cultural significance.

Social significance, including public / private

ownership, emotional attachment, and pride or

remorse of ownership.

Aesthetics, considering the interaction between

ecology and aesthetics. In the past we have

accepted great architectural and aesthetic

trade-offs disregarding local site ecology and

biological functions.

Political significance, including delineating

who takes credit, pays bills, and is included.

Economics, including analysis of values

produced versus costs.

Site circulation and access, including

movement around and across the site, how

access is allowed, and security issues.

Liability and environmental vandalism,

including safety, noise pollution, traffic control,

and asset loss.

Regulatory environment, including zoning,

endangered species, wetlands, and erosion.

Cultural practices and public awareness

including herbicides, tree removals, topping, and

perceptions of existing programs.

Once a site can be viewed in its ecological and

societal context, an ecological restoration process

can be fitted within the identified constraints to

maximize ecological and biological values in a

sustainable manner. An urban forester should list

site constraints in a carefully prepared management

plan by prioritized order from the most limiting to

least limiting. For each constraint identified in the

management plan, plans for dealing with the

constraint need to be included.

Management Units

In our assessment system for identifying and

prioritizing process and site constraints, a

management unit must be identified and delineated.

Without mapable management units, discrete

boundaries for treatments, and accurate planning

edges, management confusion can exist as well as

administrative accountability problems. What is the

space and its dimensions for your restoration plan?

What is the ecological management unit?

An ecological management unit (EMU), the

smallest treatable unit -- smallest restorable unit --

must be the focus for restoration management

activities. An EMU is a human-defined, limited area

which can include one or more ecosystems. Site

assessment requires identification, delineation, and

declaration of an ecological management unit

Chapter 7: Site Assessment and Soil Improvement 5

(EMU). In natural resource management, a written

management plan can not be fulfilled without

understanding what is being managed, for what

purpose, and its size, shape, or form. From an

ecological restoration standpoint, the criteria we

must use to apply, maintain and evaluate our actions

depend upon our abilities to delineate an ecological

management unit.

The necessity for setting boundaries and

management limits is self-evident for any restoration

manager. Unfortunately, many academic concepts

of ecosystems fail to provide walls, limits or

boundaries. The landscape includes many

interconnected smaller ecosystems of various spacial

scales, overlapping with each other and the

restoration site. The conceptual problems with these

ideas of ecosystems is which one you are trying to

restore? What sub-division? What portion? How do

you declare victory, evaluate actions, or prepare

budgets if the spacial extent of the ecological

restoration area is nebulous? Discrete boundaries for

the restoration project are critical to planning,

implementing and the success of the project.

Politics and Science

Through the assessment process, the primary

concern has been the ecological restoration of the

EMU. However, it is just as important to the success

of any restoration project to include the

stake-holders, decision-makers and surrounding

social systems in all phases of the project (Figure 3).

It is also critical to the project that science and

politics remain separated. An ecological restoration

project needs to compartmentalize and keep separate

ecological science from social, cultural and

economic-based decision making. Physical,

chemical, and structural facts need to be clearly

separated from human feelings, needs and value

judgements. Ecology is apolitical in the natural

world. Politicizing ecology can destroy objectivity

in decision-making and allow mis-use or selective

use of scientific information. Professional respect

and accountability can be eroded quickly if you lose

sight of the science and political separation.

Figure 3.1 Photo by Rob Buffler

Figure 3.2 Photo by Mary Duryea

Figure 3. It is important to the success of any restoration

project to include stake-holders, decision-makers and

surrounding social systems in all phases of a project.

The Assessment Process

There are many tools and methodologies for

assessing damaged and exhausted EMUs to

determine whether they are viable candidates for

restoration, and to identify the magnitude of efforts

required for a restoration project. Presented here is a

basic checklist for an assessment process. It is

assumed you have already set goals and objectives,

and identified a number of constraints (see Chapter

5 - Developing a Management Plan). Assessment

is a part of the planning and management process,

not a disjunct and separate piece. Remember, every

site and situation will be different. You are

encouraged to develop assessment systems which

best serve your ecological and political situations.

Chapter 7: Site Assessment and Soil Improvement 6

The following assessment process has been used

successfully for urban and community forest sites,

land development interface sites, and for damaged or

abused environmental management sites in Europe

and North America. This assessment process is

presented as a guide to collecting information for

planning restoration activities in an ecological

management unit. The following information must

be determined:

1. Quantify

The first step is to define and delineate (on maps

and on the ground) the EMU and its context in the

landscape. This step is an inventory of resources,

processes and rates of change, and a classification or

analysis of what exists (quantify and graphically

classify).

2. Size

Assess the EMU and determine if it is large

enough to sustain the values and outputs expected.

This step is an assessment of scale problems

including biodiversity, genetic variability,

reproductive spheres, and colonization potential.

3. Space

Assess the spacial relationships between the

EMU and other ecosystems in the landscape for

current and future connectivity, fragmentation, and

ecological integrity. Record quality and quantity of

information on ecological gaps, fragments, corridors,

and ecotones.

4. Diversity

Assess the variability, density, and diversity of

species and their habitat. Included should be

information on natives, exotics, and habitat

composition for key species.

5. Time

Temporal changes across a site will be many.

Assess the pattern and timing of when individuals

and species are expected to age and die, and

successional patterns for the site (See Chapter 4 -

Plant Succession and Disturbances).

Considerations are life-spans of key and dominant

species, current age classes and structures, and how

life-forms are removed or enter a site.

6. Disturbance

Assess historical and present disturbance

regimes including the type, intensity, and frequency

(see Chapter 4 - Plant Succession and

Disturbances).

7. Stress

Assess historic and present stress components of

the site. Stress includes anthropogenic problems,

competition, allelopathy, pests including invasive

species, and environmental constraints to survival

and growth (see Chapter 9 - Invasive Species).

8. Natural Cycles

Assess the effort and consequences of activities

to recover historic material and energy cycling

processes. Assess how to restore the natural cycles

such as nutrient cycling to encourage a more natural

support (lower maintenance) of site functions and

move away from human-centered support. Take

special care in observing energy flow, the hydrology

on the site, and nutrient status and processing (see

Chapters 2 and 6 - Ecological Processes and

Restoring the Hydrologic Cycle)

9. Organic Matter

The presence of organic matter on the site is

critical to the nutrient cycle and the health of the site.

Special concern should be targeted at large woody

debris and soil organic matter.

10. Management Resolve

Assess on-site and within the management

system the appreciation of ecological realities

(sometimes natural ecosystems may appear messy,

unkept, or chaotic compared to sites with single

species or grassy parks) and acceptance of change.

11. Action Check-List

The principle means of restoring the EMU can

include:

Chapter 7: Site Assessment and Soil Improvement 7

• Re-instituting successional processes.

• Re-instating disturbance regimes.

• Enriching the genetic resources (living things),

including:

• Adding and/or replacing "key" organisms

(trees, vertebrates, fungi, arthropods,

worms, etc.)

• Modifying native systems to include more

trophic levels.

• Improving site resources, including:

• Increasing organic matter (woody

biomass, soil and litter).

• Improving soil exchange capacity

(element cycling and holding).

• Improving soil health (pore space and

structure).

• Increasing water availability (cycling, use,

flow,

• Modifying or enriching nitrogen cycling.

• Altering site light resources (light and

shade management).

• Minimizing stress on key species.

• Contain or eliminate heavy metals.

• Control pollution.

• Control heat.

• Control exotics.

• Physically protect site from mechanical

and chemical damage.

• Control oxygen availability and water

drainage trade-offs in soil.

Soil Improvement

Introduction

Soil health management is a very critical portion

of a renovation process to sustain ecological

functions. Soils are the primary contact point

between living organisms and are a biologically,

chemically, and physically active portion of the

environment. Soils are the ecological interface for

materials and energy exchange, and a matrix that

supports, houses, and stores essential elements and

living things. Mineral, dead, near-dead, and living

things are all held in a thin layer of ecological volume

called soil. Conceptually, a soil for restoration can be

considered a matrix of living things rather than an

engineering material. Soil is the basis for urban

ecosystem productivity.

The resources soil provide to support ecosystem

productivity include:

• growth materials (15 of 18 essential elements

plus water from the soil,)

• transport and storage of growth materials,

• buffer change and variability,

• physical and chemical protection,

• structural growth matrix, and

• primary energy exchange surface.

Good soil management is essential for (and a

part of) healthy and sustainable ecological systems.

A number of soil features become degraded,

destroyed or exhausted over time in highly stressed

environments. Soil assessments concentrate on those

chemical, physical, and biological features of soil

resources which can limit colonization, survival, and

growth of living things. Restoration activities need to

be prescribed carefully in trophic level order to

assure success--in other words, truly start at the

bottom and restore upward. The soil is the

foundation upon which we restore ecosystem

functions and structures (Figure 4).

Chapter 7: Site Assessment and Soil Improvement 8

Figure 4. Soils form the basis for urban forest ecosystem

productivity. Photo by Larry Korhnak

Ideal Soils

Ideally a soil is composed of materials and space

in roughly equal proportions. A "perfect soil" for

ecological development is considered to have 45%

mineral materials and 5% organic materials (living

and dead), and 50% pore space divided equally

between large air-filled pores and small water-filled

pores. A perfect soil has horizontal layering

developed through an assortment of genesis

processes. These layers are called "horizons"

(Figure 5). Horizonation requires time to develop

from the last major disturbance on the site. As such,

most urban soils have little horizonation, but do

develop these characteristics if allowed to remain

relatively undisturbed.

Figure 5. Ideal soils have horizons or zones where

different process occur such as organic matter

breakdown, weathering, leaching, and material

accumulation. Photo by Larry Korhnak

An ideal soil profile (from the surface

downward) would have four horisons as seen in

(Table 1). Most urban soils deviate wildly from ideal

soil features, but by knowing theoretical limits,

restoration changes can be judged for value.

Table 1. An ideal soil profile.

Horizons Description

A horizon surface soil with maximum organic

matter accumulation, good porosity,

many living organisms, most active

tree roots, and represents a zone

leached by precipitation and soil

weathering factors

B horizon "subsoil" where clays accumulate

C horizon oxidized parent material

D horizon unoxidized parent material

Urban Soil Features

Urban soils have many unique features. Urban

soil features which are most limiting to a restoration

process are listed below:

• great vertical and horizontal variation,

• compacted structure,

Chapter 7: Site Assessment and Soil Improvement 9

• modified infiltration, percolation and water

holding capacity,

• crusting or water repellent surface,

• pH changes (usually increasing pH),

• restricted aeration and drainage,

• impotent or disjunct element cycling,

• modified ecology of soil organism activities

(no organic material),

• toxins and contaminants,

• soil temperature changes, and

• reduced mineralization rates (from organic

matter) and accelerated nitrification.

An average urban soil is disturbed and highly

variable caused by digging, cutting, filling, trenching

and scraping (Figure 6). The average urban soil has

few essential elements, poor drainage, and a

compacted, heavy texture. Within the soil are many

blatant, sharp interfaces between layers and parts.

The average urban soil has little organic matter and

surface litter with a low diversity and small number

of beneficial organisms. Erosion remains a terrible

problem.

Figure 6. Urban soils are often altered by digging, cutting,

trenching, scraping and, as shown here, by filling. Photo

by Larry Korhnak

The Manageable 10

The soil attributes that affect and control soil

resources, and present the most potential for

ecological restoration success are:

1. texture

2. structure

3. bulk density

4. water

5. aeration

6. element holding capacity

7. essential elements

8. organic matter

9. contamination

10. trophic enrichment

Each of these restoration attributes represent

opportunities for a manager to be successful.

1. Soil Texture

Texture is the relative percentage of sand, silt,

and clay-sized particles in the mineral portion of the

soil. Most soils are a mixture of various particle sizes

and distributions. Texture directly affects water and

oxygen, and indirectly affects essential elements.

The clay component of a soil dominates soil activity.

As clay contents approach and exceed 20-25% in the

soil particle mixture, the chemistry and limitations of

the clays control soil attributes (Figure 7).

Soil texture can be modified by amendments but

it is not practical for large scale projects. For

example, on an average house lot the top foot of soil

weights 400 tons. To convert soil texture in this zone

from a clay soil to a sandy clay loam requires the

removal of 120 tons of the clay soil and its

replacement with 120 tons of sand. At the one-foot

depth mark, the interface between the first foot and

second foot of soil would be limiting to tree growth.

The texture change provided by this amendment

process successfully increased aeration pore space.

It is clear from this example that soil texture changes

are of little practical importance other than in beds,

containers, or planting holes.

One area where texture is critical to

understanding restoration processes is at textural

interfaces. An interface is where soil texture changes

Chapter 7: Site Assessment and Soil Improvement 10

Figure 7. Texture is the relative percentage of sand, silt,

and clay-sized particles in the mineral portion of the soil.

over short distances (less than 1- 4 inches). These

interfaces are most often horizontal layers, but can

be lens or vertical layers which texturally vary from

adjacent layers. Textural interfaces below the soil

surface can provide many gas and water exchange

limitations.

There are four primary texture interface types:

Type 1 Interface = finer texture soil to

coarser textured soil (small pores to large

pores) -- water can not move from one layer

to the next until the upper fine-textured layer

is saturated (water will remain in the fine soil

if it is at less-than-saturation.) Bathtub effect!

Type 2 Interface = coarser textured soil to

finer texture soil (large pores to small pores)

-- water movement is away from coarser

textured soil and limited by water movement

into finer soil (water can build-up at the

interface if in excess, but continues to move

into finer soil.) Drought effect!

Type 3 Interface = coarse horizontal or

vertical layers of gravel, large sand, organic

materials, etc. -- water must saturate soil

above the coarse layer before moving into the

coarse layer (water will perch above the

coarse layer.) Because of hydraulic

conductivity processes, the tree depends upon

local water and local essential elements. This

interface limits rooting area from the bottom.

Perched water, limited oxygen flow!

Type 4 Interface = gradual texture changes

where mixing or incorporation has spread out

the interface distance -- good interface width

for minimizing water problems is 1 foot. (1- 4

feet depending on texture changes.)

Working examples utilizing trees showing the

importance of interface problems to restoration work

follow. Tree #1 is planted in a native coarse soil with

a root ball composed of fine textured soil. Water is

added immediately above / over the root ball.

Because of the interface (rapidly changing average

pore sizes), water can not move across the interface

until the soil in the root ball saturates. The result is

the tree sits in a near-saturated soil much of the time.

(Type #1 Interface). An additional result is water

applied to the site will not necessarily enter the root

ball leaving the tree drought stricken.

Tree #2 is planted in a native fine soil with a root

ball which is composed of coarse textured soil.

Water added directly above the root ball will move

across the interface, although slowly. Water will be

drawn into the surrounding fine textured soil from

the large pore spaces of the root ball soil. The result

is a tree under low soil water conditions much of the

time. (Type #2 Interface).

Tree #3 is planted in native fine soil with a root

ball composed of fine textured soil and a layer of

gravel in the bottom of the planting hole. Water will

be perched above the coarse layer and move through

only as the soil above saturates. The result is water

and oxygen movement through the soil is disrupted.

(Type #3 Interface). A tree will have a limited

rooting area until it breaks through the coarse layer.

Depending upon the scale and duration of water and

oxygen movement disruption in the soil, roots may

never escape soil constraints.

2. Soil Structure

Structure in soil is represented by aggregates of

the basic texture particles in specific shaped

structures. The primary types of soil structure are

platelike, prismlike, blocklike and spheroidal. Soil

particles are held in these structural aggregates by

Chapter 7: Site Assessment and Soil Improvement 11

adhesive forces from organic, colloidal, or metal

oxide coatings. Soil structure can be modified by

amendments.

Organic matter amendments (composted organic

material not merely organic mulch) promote

granulation in both sandy and clay soils. Organic

materials added to sandy soils generate more small

pore development, which sandy soils lack. Organic

materials added to clay soils generate more large pore

development, which clay soils lack. In both coarse

and fine soils the improvement in structure from

organic matter additions improves the availability of

water and oxygen (Figure 8). Care must be

exercised when working with clay soils because they

are very susceptible to compaction of pore spaces

and destruction of structural units when wet.

An example of soil improvement through

structural change could be compared to the attempted

textural change example given above. The example

cited modifying water and oxygen availability in the

top foot of an average house lot. Adding 1.2 tons of

composted organic material to the soil will have a

similar effect as replacing 120 tons of soil with sand.

A simple conclusion is restoration can be successful

and cost-effective by concentrating on soil structure

changes rather than soil texture changes. A critical

feature of organic matter additions is do not allow

sub-surface layers to develop.

Figure 8. Organic matter can add beneficial structure to

clay and sands. As shown here organic matter gives sand

a granular structure that improves water availability. Photo

by Larry Korhnak

3. Bulk Density and Pore Space

Bulk density is the relative density of a soil

including its pore space volume. It is measured by

dividing the dry weight of a soil by its volume. If

soil was just mineral material, an average density of

common minerals would be 2.65 g/cc. As we

discussed earlier, half of an ideal soil should be pore

space (voids or spaces between solid soil

materials)-- which makes ideal bulk density 1.3 g/cc

(50% pore space.)

The characteristics of pore space varies by soil

texture. Sands have many large pores filled with air.

Clays have many small pores filled with water. Clays

have greater total pore space than sand but it is filled

with tightly held water. For example the typical air

filled pore space of a drained soil would be 35% for

sand, 25% for silt, and only 15% for clay.

Unfortunately urban soils are moderate to

heavily compacted by footsteps, light vehicles, and

heavy construction vehicles. This compaction

shrinks large pore spaces which usually hold air, as

well as decreasing total pore space (increasing bulk

density.) Depending upon soil texture and structure,

tree root growth problems can be initiated with only

small increases in bulk density (Figure 9).

Figure 9. Bulk density in urban soils is often increased by

compaction. The decrease in pore space can cause tree

growth problems. Photo by Larry Korhnak

Chapter 7: Site Assessment and Soil Improvement 12

For example, roots have difficulty physically

penetrating beyond a bulk density of 1.75 g/cc.

Oxygen availability constrains tree root growth as air

pore space drops below 15% volume of the soil.

Table 2 presents soil attributes where tree root

growth begins to be significantly limited for each soil

texture class.

Compaction prevents root and soil functions

essential to life. Compaction is found across all

types of sites. Construction sites have been found to

average 60% greater bulk density than neighboring

native soils. A rule of thumb is an increase in bulk

density by 1/3, causes a loss of 1/2 root and shoot

growth. Compaction is not easily reversed. Harvest

sites (logging decks, major skid trails, and forest

road trails) can be effectively mapped after 40 years

based only upon soil compaction and tree growth

data. Time does not heal all.

Table 2. Soil attributes where root growth begins to be

significantly limited for each soil texture class.

soil

texture

root-limiting

bulk

density

g/cc

root-limiting

% pores

filled with

air

% total pore

space in

soil

sand 1.8 24 32

fine

sand

1.75 21 34

sandy

loam

1.7 19 36

fine

sandy

loam

1.65 15 38

loam 1.55 14 41

silt loam 1.45 17 45

clay

loam

1.5 11 43

clay 1.4 13 47

There have been many compaction treatments

proposed over the years. Surface tillage as deep as

possible (at least 8 inches) and sub-soiling (winged

bars below 16 inches), can be used when no tree

roots are present to decrease bulk density. A soil can

be amended with non-compressible, porous materials

like washed flyash to provide pore space. Soil can

also be amended with large gravel or small blocky

stones to provide large airspaces and a bearing

surface.

When trees are present, mulching can be used to

minimize continued compaction pressure, and

dissipate raindrop energy and surface erosion. Core

aerators made for deep penetrations (12-16 inch

long) can be effective but in heavily compacted soil

may not be effective beyond 3-5 inches deep and may

be difficult to use. Punch aerators create open soil

space but compact the side of the surrounding hole.

Surface aerators (2-4 inches deep) generate a low

bulk density zone over a compacted zone just below,

thus presenting a very limited root colonization area.

Aerators are undergoing a major conceptual

re-engineering period for assisting with restoration of

severely compacted soils.

The primary means of reducing compaction

problems both concentrate on generating more

surface areas/ecological volume for root initiation

and colonization. The two methods are vertical

mulching and radial trenching. Vertical mulching

uses a series of vertical holes augured into the soil to

a depth of 14-24 inches on 2-3 feet centers under the

drip line of the tree. The treatment can be expanded

into soil areas useful for root colonization. The 1-2

inch diameter soil cores should be backfilled with

washed, graded, and non-compressible materials

open to the atmosphere. A composted organic matter

and mineral light mix would be ideal with an organic

mulch placed over the surface. Over time, material

subsidence will require refilling holes.

Radial trenching uses a trencher or thin

back-hole to dig trench lines from 2 - 14 inches wide.

Each trench line begins on the ground surface 4-6

feet away from the tree trunk. As the trencher moves

outward from the trunk area, the cutting head is

allowed to dig downward to its operating depth. The

trenches are backfilled with washed, graded, and

non-compressible materials open to the atmosphere.

Chapter 7: Site Assessment and Soil Improvement 13

A composted organic matter and mineral light-mix

would be ideal with an organic mulch on the surface.

Various growth stimulators and soil enrichment

materials may be added. Five to six trenches are

initiated near the trunk and extend out to one and

one-half the drip-line distance. As the distance

between trenches increases, intermediate new

trenches can be added, depending upon site and soil

limitations.

4. Water

Water is held around the soil particles and within

soil pores. Water sticks together and is pulled

through a soil to the top of a tree by the process of

transpiration. Depending upon soil texture, some

water is held too tightly by soil particles to be

extracted by trees. The traditional soil-water terms

are defined in Table 3:

Table 3. Definition of soil-water terms.

Term Definition

Field

capacity

the amount of water held against

the force of gravity

Permanent

wilting point

water content level where the soil

holds water so tightly that trees can

not extract it (water contents at or

below this level are unavailable to

the tree)

Tree-available

water

water present in soil between field

capacity and permanent wilting

point that trees can extract from the

soil

Tree-available water varies by soil texture.

Sandy loams probably have the greatest amount of

water available to a tree of any soil texture. Clays

contain more total water than other texture types, but

most of this water (up to 75%) remains tied tightly

to the clay surfaces and micro pores, and so,

unavailable to a tree. Sands contain little water but

what is present is almost all available for tree up-take

and growth.

Water movement can be disrupted in urban soils.

The many textural/structural interfaces within urban

soil profiles, allow many water and oxygen

availability problems to exist. In highly disturbed

urban soils with many interfaces, water around the

roots is critical to tree survival. Even the process of

installing irrigation (depending upon backfill) can

change water flow through the soil. Irrigating to

correct turf water shortages will usually over-water

trees. Trees should be separately zoned for irrigation

in a landscape.

As site water inputs exceed outputs, soil health

and tree roots are damaged. In addition, a number of

pathogens thrive under poor drainage conditions.

Drainage can be estimated by perculation tests.

Irrigation should be adjusted to the drainage class of

the soil, seasonal precipitation, and evaporation

demands. A $20,000.00 / 100 year old tree is

irreplaceable in three generations while the turf and

small shrubs are immediately replaceable at a modest

price. Priority must be given to high-value landscape

items like trees (Figure 10).

Figure 10. Irrigation should be adjusted to the drainage

class of the soil, seasonal precipitation, and evaporation

demands. Priority must be given to high-value landscape

items like trees. Photo by Larry Korhnak

In the urban landscape the generation and

transportation of heat can have an impact on water

use in a tree and on a site. For every 18 degrees F

increase in temperature above 40 degrees F, site and

tree water evaporation and respiration almost double.

The more heat a site must dissipate, the more water

must be evaporated. Lack of evaporative surfaces

and few heat blocking or dissipating shade structures

allow heat accumulation on a site. Heat

accumulation "cooks" trees and soils present, while

heat moving onto the site from surrounding

hardscapes demands site water use for evaporation.

Irrigation must be tuned for handling additional heat

loads.

Chapter 7: Site Assessment and Soil Improvement 14

5. Aeration

Aeration is oxygen moving in large soil pores

from atmosphere to tree root surfaces. Soils have

combinations of aerobic and anaerobic sites and the

balance between them is constantly changing through

the seasons, days, or years. Oxygen movement can

only be assured by the presence of large pores,

fracture lines, decayed root lines, or aeration

columns. Compaction and flooding can produce

many water-filled pores. Oxygen moves 1,000 times

slower across a water barrier (water-filled pore) than

across a gas filled pore. Therefore wet or compacted

soils do not allow oxygen to effectively move to

roots. Any place where soil atmospheric oxygen

drops below 5% concentration, root growth stops.

As oxygen moves in the soil, many organisms

use its oxidation power before it reaches tree roots.

Under poor drainage and low oxygen conditions,

oxygen can be used up quickly. Once the oxygen is

consumed, soil organisms (not tree roots) begin to

use other elements for respiration. The respiration

sequence is oxygen, nitrogen, manganese, iron,

sulphur, and carbon. An entire year's fertilization

load of nitrogen can be respired away into inert

nitrogen gas within weeks under near anaerobic

conditions. Once the soil organisms start to respire

sulphur and carbon, many materials are formed that

will require purging or rinsing out of the soil for best

recovery. The warmer the temperature, the quicker

oxygen is consumed and the faster alternative

respiration will occur (i.e. doubling rate sequence for

respiration with increasing temperature).

Solutions for aeration problems are good

drainage and open soil surface for gas exchange. To

meet these goals, drain and sump systems can be

installed. These systems are made of perforated

pipes sunk to various depths. A drain system may

include a number of interconnected horizontal and

vertical pipes which were either pre-positioned

before planting or trenched-in afterwards. The goal

of a drainage system is to allow gravitational water

to move away from the soil and away from root

colonization areas. Sump systems use large diameter

perforated pipes vertically sunk into the ground well

beyond rooting depth to allow for accumulation of

gravitational water in the pipes. These water

containing pipes can then be pumped out

periodically. These pipes can also be used to quickly

saturate a soil area by filling with water during

droughts.

The other major form of aeration modification is

accomplished by terra-forming or sculpturing the

landscape. Designing berms, terraces, raised

mounds, and topography changes from grading

practices can all be used to gain root colonizable

space. These structures must be built to minimize

erosion and should be able to withstand a 100-year

rainstorm event.

6. Element Holding Capacity

Trees take-up essential elements in ionic forms

from soils. A small portion of the essential elements

are readily available, dissolved in tree-available

water. Most essential element ions are held near the

surfaces of clay and organic particles. Clays and

portions of organic materials (humus) have

negatively charged areas that attract and keep the

positively charged ions (cations) in close proximity.

These binding sites help keep essential elements

from being washed from the site. Cations include

calcium, manganese, zinc, magnesium, potassium,

and ammonium.

Cation exchange capacity (CEC) is a

measurement of the positive charged ion holding or

storage capacity of a soil. A calculation for rough

estimation of CEC is:

CEC = ((% organic matter in the soil) X 2.0) +

((% clay in soil ) X 0.5)

The formula suggests how effective additions of

clay and composted organic matter might be to a soil.

Organic matter is four times more effective for

improving CEC as clay. For soil type and texture,

relative CEC varies: sand =1; loam=5; silt loam=8;

clay=15. Cation exchange capacity generally

increases with soil pH.

Organic materials also have surface areas with

positive charges that attract negatively charged ions

(anions) like nitrate, phosphate, sulfate, chloride,

borate and molybdate. Anion exchange capacity

(AEC) is a small part of soil chemical activity.

Anions either move freely with water, like nitrates,

Chapter 7: Site Assessment and Soil Improvement 15

or are bound in insoluble forms like phosphates

(Figure 11).

Figure 11. Organic matter has many charged areas that

attract and conserve elements important for plant growth.

Photo by Larry Korhnak

7. Essential Elements

There are a number of elements essential to the

life and health of living things. Air (CO2) and soil

water (H2O) provide three essential elements (O, H,

and C). Soil provides the remaining 15 essential

elements. An ecological system will progresses until

any one essential element or process becomes

limiting. It matters little how much nitrogen is added

to a site if zinc is the most limiting element to tree

growth. Below is Table 4 which provides a general

and relative ratio of essential elements in trees.

Table 4. Ratio of essential elements in trees. (* = from

CO

2

and H

2

O)

MACROS: MICROS:

hydrogen 60,000,000* chlorine 3,000

carbon 35,000,000* iron 2,000

oxygen 30,000,000* boron 2,000

manganese 1,000

nitrogen 1,000,000 zinc 300

potassium 250,000 copper 100

calcium 125,000 molybdenum 1

magnesium 80,000

phosphorus 60,000 Transformers:

sulfur 30,000 cobalt

nickel

On most terrestrial sites, nitrogen is usually

limiting for a number of reasons. Phosphorus can be

limited on wet and poorly drained soils. Fertilization

prescriptions should be nitrogen-centered but assure

easy phosphorus availability. Elements most often

limiting in order of importance are N, P, Mg, and K.

Excessive nitrogen fertilization has caused a number

of overdose events and over-medication programs to

damage ecosystems and trees, especially the very old

and the very young. Ecologically, both large doses

and no doses can be less productive and less healthy

than mid-ranges.

8. Organic Matter

Organic matter is once-living materials

decomposing and eroding back into the soil (Figure

12). As noted in the above discussions, organic

matter can improve soil structure, bulk density, water

and element holding capacities, and aeration.

Organic materials provide fuel, food and habitat for

the detritus engine of the soil. Urban forest soils

often have no or limited organic matter as well as the

associated flora and fauna which break-up and

decompose organic materials. Therefore the natural

processes of element cycling usually occur only in

small amounts on urban sites. Leaving fallen plant

materials on site and/or incorporating organic

admendments can greatly improve soil health and

in-turn the health of the urban forest.

9. Contamination

Soil is both easily polluted and difficult to clean

or restore. Contamination effects can out-right kill

and damage ecological and biological systems. In

addition, contamination acts to disrupt and poison

restoration processes (Figure 13). General classes of

contamination in soils are: lead and other heavy

metals (a legacy that does not decay); pesticides;

salt; petroleum products; biological excretions

(urine, feces, etc.); litter/construction materials; soil

Chapter 7: Site Assessment and Soil Improvement 16

Figure 12. Organic matter is once-living materials

decomposing and eroding back into the soil. Photo by

Larry Korhnak

crusting (hydrophobic surfaces from petroleum,

allelopathic materials, and organic coatings); and

buried trash from past construction and land-uses

(cement wash-outs, general land fills, garbage dump

(current or historic), poor coverage with top soil,

methane, and soil subsidence associated problems).

Figure 13. Soil is easily polluted but difficult to clean or

restore. Soil contamination disrupts biological and

restoration processes. Photo by Larry Korhnak

Three examples of contamination which might

disrupt ecological restoration activities include:

1. Lead in soils from the days of leaded gasoline

(in Minneapolis, MN it was estimated that 2,000

tons per year of lead dust from autos fell on to

soil surfaces),

2. Animal and human wastes concentrate toxins

and salt content in fresh feces and urine. There

is also a risk of viral and bacterial disease with

contact of in-place soil or air-bourne soil, and

3. Floods wash down the contents of storage bins,

sheds and tanks from up-watershed to those

below, generating deposition and clean-up

problems.

Solutions to soil contamination problems begins

with identifying concerns and soil testing.

Associated with testing for contamination should be

development of a water and soil contamination map

of the site. Once this map is complete, a

prioritization system can be developed for other

treatments or activities. Contamination treatments

could include the complete removal or tie-up of

materials in the soil using pH, plasma jets,

organisms, chemicals, and /or barriers. Removal of

contaminated soil might fall under toxic waste

regulatory agencies to supervise. Mulching and

careful nitrogen fertilization across well-drained sites

can accelerate bacteria and soil processes which can

minimize or destroy some contaminants. Cultivation

or addition of a wetting agent might assist with

health restoration by breaking-up soil and organic

material crusts. Keep human contact away from

contaminated areas including collecting or

consumption of plant tissues, fruits, nuts, and

mushrooms.

10. Trophic Enrichment

Enrichment is the addition, infection,

contamination, or repatriation of the site with various

living things. A simple teaching model uses the term

"WAFBOM" which represents worms, arthropods,

fungi, bacteria, and organic material added to a site.

This multi-level trophic enrichment attempts to

restart the detritus ecological engine needed for soil

and tree health (Figure 14). There remains a concern

about infecting sites with exotic organisms,

especially worms and fungi. Gene set trade-off must

sometimes be made in site restoration. Fully

conceived and operating processes, once established,

may eventually eliminate poor species or organisms.

Many urban sites for restoration are far removed

(islands) from sources of reintroductions and

infections of living things. If you build the perfect

restored system, species may find the site or not (if

you build it, they may not come). Active intervention

and infection at multiple trophic levels can accelerate

the site colonization process. Urban sites are tough

Chapter 7: Site Assessment and Soil Improvement 17

on beneficial organisms like arthropods, worms,

fungi and bacteria especially where increased heat

loads quickly "burn-out" organic matter in the soil.

Many sites could benefit from organism infection in

the nursery, or organism inoculum applied at

planting time.

Organic matter remains a universal resource for

restoration of urban forest sites. The organic matter

is the feed stock and habitat for beneficial soil

organisms and for tree roots. Composted organic

matter can be top-dressed over the site with a thin

protective layer of non-compressible, organic mulch

covering. Restoration managers are then placed in a

position of animal husbandry (microbe-jockeys).

Managers should beware of the wolves (pathogens

and exotic higher plants) among the sheep. Native

gene sets should always be conserved, but exotics

might help recover a site faster, serving as a nurse

crop or successional predecessor. Ecological and

genetic trade-off must always be made.

Figure 14. Worms, arthropods, fungi, bacteria, and

organic material often need to be added to restoration

sites to restart the detritus ecological engine needed for

soil and tree health. Photo by Larry Korhnak

Conclusions

A key component in assessing sites for

ecological restoration is developing, both for your

own reference and others, a site picture, also called

determining the site context. Each site should be

assessed for its ecological context and societal

context. An ecological management unit (EMU), the

smallest treatable unit -- smallest restorable unit --

must be the focus for restoration management

activities. In addition to the ecological

considerations for a project, it is also important to the

success of any restoration project to include the

stake-holders, decision-makers and surrounding

social systems in all phases of the project. Site

assessment is a part of the planning and management

process, not a disjunct and separate piece. Remember

every site and situation will be different. An initial

site assessment should include inventory of

resources, space, size, diversity, temporal changes,

disturbances, stress, natural cycles, organic matter,

management, and a final action-list.

A restoration process includes an assessment of

present conditions, how they are changing, and

concentration of efforts on site factors which can be

repaired or improved -- soil health components.

Good soil management is essential for (and a part of)

healthy and sustainable ecological systems. Since a

number of soil features becomes degraded or

destroyed over time in highly stressed environments,

soil evaluation and improvement becomes

imperative. An average urban soil has few essential

elements, poor drainage, a compacted, heavy texture,

with little organic matter, low diversity and small

number of beneficial organisms. Restoration

activities need to be prescribed carefully in trophic

level order to assure success -- start at the bottom

and restore upward. The soil is the foundation upon

which we restore ecosystem functions and structures.

The soil attributes affecting and controlling soil

resources to be restored successfully include texture,

structure, bulk density, water, aeration, element

holding capacity, essential elements, organic matter,

contamination, and trophic enrichment.

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Chapter 8: Enriching and Managing Urban Forests for

Wildlife1

Joseph M. Schaefer2

1. This is Chapter 8 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kämpf Binelli, and L.V. Korhnak, Eds.) produced

by the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Joseph M. Schaefer, Professor, Dept. of Wildlife Ecology and Conservation and Director, Center for Natural Resources, Cooperative Extension Service,

Institute of Food and Agricultural Sciences, University of Florida, PO Box 110230, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Many positive outcomes result from enriching

and managing urban forests for wildlife. However,

effective management requires careful planning.

Baseline data on wildlife species that are currently

using the site should be collected prior to the

implementation of any plans. A site evaluation is

needed to determine what ecosystem components

need to be installed to improve the ecological value

of the property. Clear goals and objectives must be

established to effectively guide the process. Three

approaches to implementing a plan are managing

habitat, stocking species, and controlling negative

impacts of people and pets. Periodic monitoring of

species occurrence on the site will help to measure

success and will also indicate ways the plan should

be revised to obtain better results if necessary.

Introduction

The concept of accommodating both humans

and wildlife in the same area is nothing new.

Humans have always lived with other animals.

However, over geologic time, human populations

have increased and drastically extended their

dominance on the landscape. Many plant and animal

species that were once wild are now domestic.

Ecosystems that evolved through millennia of

natural processes and stochastic events have been

severely humanized within decades.

Many benefits can result from efforts to enrich

and manage wildlife in urban forests. Native animals

attracted to properly managed sites can provide

recreational and educational opportunities for local

residents (Figure 1). People involved in planning,

installing and using areas managed for wildlife

realize how decisions can directly influence

environmental quality and are likely to develop a

better land ethic. These areas also include the use of

native plants that require less water and nutrients

than exotic grasses and ornamental plants.

Developing a Plan for Wildlife

Effective wildlife management cannot be done

on just a whim. It requires careful planning. The

current condition of the site(s) needs to be

determined, and then a team of experts and

stakeholders should discuss and agree on what they

want to accomplish. An effective wildlife

management plan should contain base-line data, a site

evaluation, goals and objectives. For more

Chapter 8: Enriching and Managing Urban Forests for Wildlife 2

Figure 1. Native animals attracted to properly managed

sites can provide recreational and educational

opportunities for local residents. Photo by Larry Korhnak

information on developing plans for restoring the

urban forest ecosystem, see Chapter 5 - Developing

a Management Plan.

Base-line Data

Data on the current status of wildlife should be

collected before any other decisions are made. These

data will show which species are already present on

the project site(s). By comparing this list to a list of

species that have been documented to occur in the

same habitat types or ecosystems within the same

geographic range, you can identify those species that

could be accommodated. A team of experts can

determine the species or groups of species on which

the project should focus.

Small Snakes, Turtles, Lizards, Frogs,

Toads, Salamanders, Mice and Shrews

Acceptable scientific survey methods should be

used to collect these data. A drift-fence, pitfall trap

array is the best method to collect animals that crawl

or walk on the ground (for example: small snakes,

turtles, lizards, frogs, toads, salamanders, mice and

shrews) (Figure 2). The materials needed for this

include a shovel, two 5-gallon plastic buckets with

lids, tin snips, and one 10-foot x 2-foot x 1-inch

board. In your project area, at least 5 yards from an

edge, dig a hole about 2-feet deep and 1-foot wide.

Make several holes in the bottom of the buckets by

drilling or hammering a nail or screwdriver. The

holes in the bottom will help rain water to drain out

of the bucket so caught animals will not drown. Place

one of the 5-gallon buckets in the hole so the top

edge is level with the ground surface. Cut a 1-inch

slit about 3 inches deep in the rim of the bucket with

tin snips. Dig a 10-foot long trench about 3 inches

deep out from the slit in the bucket. Lay the board

down next to the trench to determine where to dig a

hole for the second bucket (about 9.5 feet from the

first bucket). Dig a hole for the second bucket; cut a

slit in the rim; stand the board on its side in the

trench and in the slits in the two buckets; and backfill

dirt against both sides. You may need to support the

board in the middle with a stake or two. If your site

is large enough, you can use several bucket arrays

placed in different microhabitats (for example,

shaded and unshaded areas) so you can see if some

species have a preference for different areas. Shade

each bucket with the lid elevated at least 6 inches

above the ground to allow larger animals such as box

turtles to enter. Place a damp sponge in the bottom

on the buckets so captured animals will not dry out.

Collect these data for four consecutive days of each

season.

Figure 2. A drift-fence, pitfall trap array is the best method

to collect animals that crawl or walk on the ground, such as

small snakes, turtles, lizards, frogs, toads, salamanders,

mice and shrews.

Larger Mammals

Larger mammals do not have to be caught to

record their presence. Raccoon, opossum, fox, and

others can be surveyed with tracking stations

(Figure 3). A tracking station consists of a bare soil

area (about 3-feet in diameter) covered with a layer

of dry Quickcrete (to better detect prints). In the

center, place a cotton ball immersed in oil or water

from a tuna fish can and placed on a stick pushed into

the ground. Check for tracks early each morning for

four consecutive days.

Chapter 8: Enriching and Managing Urban Forests for Wildlife 3

Figure 3. Larger mammals such as raccoons can be

surveyed with tracking stations. Photo by Larry Korhnak

Birds

A stationary count method is recommended to

most effectively detect birds in various layers of

vegetation (Figure 4). Count stations should be

permanently marked outside and on a map to assure

reuse consistency. Select locations that will give you

the best chance of detecting birds on the site.

Usually, at least one station located about 50 feet

from the site will give you an opportunity to see birds

without scaring them away. Survey at this station

first. Then go into the site to survey at one or more

stations. Space your stations about 100 yards apart.

If your site is smaller, then use only one station.

Approach each station quietly. Wait one minute at

the station for the birds to get used to you before

counting. Record all birds seen or heard for the next

5 minutes. Count only those birds that appear to be

using the site, not those merely flying over it. Bird

counts should begin as close to sunrise as possible on

calm, clear mornings. Bird surveys should be

conducted four consecutive days of each season.

Figure 4. A stationary count method is recommended to

most effectively detect birds in various layers of

vegetation. Photo by Larry Korhnak

Site Evaluation Checklist

A quick-and-easy instrument can be used to

assess the ecological value of a site. Wildlife

biologists have been using tools such as this Site

Evaluation Checklist (see Appendix 1 at the end of

the chapter) for decades to estimate site suitability

for certain species. This particular Checklist is

designed to evaluate a site based on the occurrence

and diversity of important ecosystem components. It

helps to focus attention on the items that are missing

and how a manager can increase the ecological value

by installing them properly.

Goals and Objectives

The next step is setting clear goals and

objectives that will guide the process from beginning

to end (see also Chapter 5 - Developing a

Management Plan). Goals are broad statements that

give a project general direction; objectives provide

specific destinations and time lines for different

aspects of the project. An example goal for wildlife

enrichment and management could be to enrich

wildlife within the Cincinnati park system. An

example of a specific objective would be to increase

the current number of native wildlife living in the

Cincinnati Zoological Park by 5 within the next 3

years. Progress toward achieving objectives can be

measured; progress toward goals cannot (Figure 5).

Implementing the Plan

There are three different approaches to

executing a plan to enrich and manage wildlife:

managing habitats; stocking species; and managing

people and pets. These approaches are not exclusive

of and can often complement each other.

Managing Habitats

A habitat is simply where an animal lives. It is

their address (Figure 6). When using the term

wildlife habitat, you must always refer to an animal

that lives or may potentially live there. And of

Chapter 8: Enriching and Managing Urban Forests for Wildlife 4

Figure 5. An example goal for wildlife enrichment and

management could be to enrich wildlife in a park. Photo by

Larry Korhnak

course, the animal(s) would not be able to live there

if the area did not accommodate their survival needs.

To say that a particular piece of land is good wildlife

habitat is meaningless. You must say whether it is

good for black bear, pigeons, snakes or some other

animal or group(s) of animals. In other words, it is a

good place for them to live because it provides all of

the life-sustaining requirements for the species. To

manage a habitat is to make the place more or less

suitable for a particular species depending on whether

the goal is to increase or decrease numbers of the

species. The latter goal may be appropriate for

species that are involved in damage or nuisance

situations.

Figure 6. A habitat is simply where an animal lives. It is

their address. Photo by Larry Korhnak

A natural ecosystem is a place where living and

non-living components interact in a condition that

has been relatively untouched by recent human

society. Living components include plants that fix

energy from the sun and manufacture food for the

other living components, animals. Non-living

components include soil, water, and minerals that are

important for the survival of plants and animals.

Ecosystems can be good or bad places (habitats) for

different species to live depending on whether or not

the ecosystem contains all of the components that the

species needs to survive. A tropical rainforest is a

very productive ecosystem, and provides good

habitats, or living conditions, for many species.

However, it is not good habitat for polar bears.

Many ecosystems in their existing condition do

not provide good habitats for species that once

thrived in them. As a result of human development

and land uses, many natural ecosystem components

are often destroyed and the interactions that made

them productive ecological systems no longer take

place. We can be good conservationists by putting

back or restoring as much of the original ecosystem

as possible. The theory behind improving habitat is

to build it and they will come.

Some sort of general knowledge of ecosystems

may be needed to help make this seemingly endless

task more feasible. Keep in mind that any living or

non-living component of a natural ecosystem

supports more natural ecosystem interactions than

asphalt and concrete. Even plant-free, sandy areas

may provide habitat to support a food chain

consisting of ants, ant-lions, and lizards. The

following are some ecological concepts that will help

you to be most effective in restoring an ecosystem.

The most fundamental concept that applies to

any ecosystem restoration effort is the more

diversity, the better. Restoration undertakings are

most cost efficient and ecologically effective when

the greatest diversity of ecosystem components is

provided. For example, $100 could purchase 5 holly

trees that will provide food for a variety of bird

species. Or, this same amount of money could

purchase one holly tree, an oak tree, a birdhouse,

some butterfly and hummingbird nectar plants, and

material to build a pond. These diverse ecosystem

components can provide not only berries for birds,

Chapter 8: Enriching and Managing Urban Forests for Wildlife 5

but also acorns for squirrels, nesting cover for

chickadees, nectar sources for dozens of butterfly

species and hummingbirds, and a place for eggs and

tadpoles of many frog species. This diversity

concept can also be applied to each type of

ecosystem component (e.g., trees, shrubs, perennials,

birdhouses, and water). For more information on

biodiversity, see Chapter 3 - Biodiversity.

Living and non-living ecosystem components

installed in urban areas help to restore the natural

value of sites making them better places for native

wildlife to live. In other words, management

practices that would include adding native

components would improve the habitats for many

native wildlife. These components provide some of

the essential requirements for animals: food, cover,

water, and space.

Food

Plants are the primary source of nutrients and

energy for animals. Some animals only eat plants

(herbivores or vegetarians); some eat plants and

other animals (omnivores), and some eat only meat

(carnivores). All of this eating, transfers energy and

nutrients to animals in the ecosystem's food web.

When animals eliminate some of the undigested food

or die, this nutrition is available for plants. This

cycle of life continues within the ecosystem as long

as there are sufficient food components (for more

information on nutrient cycle, see Chapter 2 - Basic

Principles).

Animals eat many plant parts. Squirrels eat

seeds, nuts, bark and buds. Insects eat leaves and

fruits. Birds eat nuts, seeds and fruits. Some of these

plant parts are only available at certain times of the

year. Buds are mostly available in the spring and

fruits and nuts in the fall. Adult cardinals eat mostly

seeds during winter, but eat insects when they are

feeding nestlings in the summer. Bluebirds eat

insects during summer, but include fruit in their

winter diet. If a site, does not have all of the foods

required at different times of the year, animals must

find food somewhere else and may leave the site

temporarily or permanently. Diets of each individual

(including humans) also change with age. Baby

humans consume different foods than adults. Baby

butterflies (caterpillars) eat leaves of specific plant

species while most adults eat flower nectar (Figure

7).

Diversity in structure and species of plants is

much better than a large number of one species

(Figure 8). Food from some plants is most available

during summer, others during the fall or some other

season. Variety provides food year-round. Some

animals nest close to the ground but feed on fruits or

insects of taller plants. Others nest in the highest

parts of the tallest trees and feed on or close to the

ground. A diversity of vertical vegetation layers will

provide suitable vertical habitat for the greatest

variety of animal species (Figure 9).

Figure 7. Baby butterflies (caterpillars), such as this Gulf

Fritillary caterpillar, eat leaves of specific plant species

while adults eat flower nectar. Photo (right) by Larry

Korhnak

Figure 8. A diversity of vertical vegetation layers will

provide suitable vertical habitat for the greatest variety of

animal species.

Cover

Like humans, wildlife species need protection

from both predators and weather. Cover also helps

restrict the amount of food available at any time to

each level in a given food web so that the energy

flow will be sustained generation after generation.

For example, if bird nests were highly visible to

predators, every egg and nestling would be eaten and

Chapter 8: Enriching and Managing Urban Forests for Wildlife 6

Figure 9. In developed areas vertical vegetation layers

are often eliminated.

no offspring would be available to continue the

important balance between predators and prey.

Cover requirements are almost as diverse as

food requirements and can be provided by both plant

and non-plant ecosystem components. Some plants

are excellent fruit or nut producers, but their foliage

is not thick enough to offer good cover (for example,

dogwood trees). Dozens of birds, mammals, reptiles

and amphibians use tree cavities for nesting and

sleeping (birdhouses can help to artificially replace

this natural component). Many birdhouses of the

same size will accommodate only those birds of a

certain size, but a diverse selection of birdhouses can

provide nesting cover for birds as large as barred

owls and as small as chickadees (Figure 10). Dozens

of species use underground burrows for nesting,

sleeping and hiding.

Figure 10. A Great-Crested Flycatcher finds cover in a

birdhouse.

Water

Fresh water is essential for most plants and

wildlife. Many animals need to drink water and other

species such as frogs and toads require standing

water during all or some of the year to complete their

life cycles. A water source on one piece of property

may be critical to all wildlife living in the entire

neighborhood (Figure 11).

While traditional, elevated birdbaths are

accessible only to birds, a pond with gently sloping

sides allows many kinds of wildlife to choose

different depths to satisfy their requirements. Even

small depressions in rocks or soil that retain water

only temporarily help satisfy wildlife water

requirements. Some amphibians mostly use

temporary ponds that hold water only for a few

months out of the year.

Figure 11. A fresh water source, such as this constructed

pond, is essential for wildlife. Photo by Larry Korhnak

Chapter 8: Enriching and Managing Urban Forests for Wildlife 7

Space

An animal's need for space is simply the size of

an area containing sufficient food, cover, and water

for the creature to survive. This size varies

depending on the density and availability of these

resources. For example, a cougar (Felis concolor)

needs about 100 miles2 (Nowak and Paradiso 1983)

and an Eastern robin (Turdus migratorius) needs

about 1/3 acre (Young 1951; Figure 12).

Most wildlife species are not able to satisfy their

space requirements on a typical urban site. Because

animals readily move across property lines, larger

suitable habitats can be accomplished if adjacent

properties containing suitable habitats are connected

to the project site.

As previously mentioned, most species have

vertical space requirements too. Some, such as the

American crow (Corvus brachyrhynchos), nest high

in tall trees but feed on the ground. Others, like the

hooded warbler (Wilsonia citrina) and brown

thrasher (Toxostoma rufum), nest close to the ground

but feed in small trees.

Figure 12. An animal's need for space is simply the size of

an area containing sufficient food, cover, and water for the

creature to survive. A robin needs about 1/3 acre. Photo

by Thomas G. Barnes

Other Habitat Concepts

Type of Ecosystem

Ecologists have developed a system of assigning

names to ecosystems according to their unique

natural characteristics. This also makes mapping,

management, and in some cases land use regulation

easier. Processes, interactions and components that

define ecological systems occur in patterns across

the landscape. Fire frequency is greater in prairie,

chaparral, and savannah sites than in riparian areas.

Areas with sandy/loamy soils are more suitable than

clay for burrowing animals such as gopher tortoises,

pocket gophers and ground squirrels.

Each ecosystem shares some characteristics with

adjacent ones, but is also very different from them.

For example, surface water flows downhill carrying

nutrients from upland to wetland sites. If a prairie

ecosystem is drastically altered during the process of

building a school facility, a highway, a house, or a

shopping center, all of the processes, interactions and

components unique to the prairie are also altered as

well as those in adjacent areas that were shared.

Replacing a prairie with temperate forest components

would not be the best way to restore the ecosystem

that was destroyed. Restoring the proper piece of the

landscape puzzle is the best way to improve the

ecology of the site so it interacts best with

surrounding areas (Figure 13).

Figure 13. In a landscape, each ecosystem shares some

characteristics with adjacent ones, but it is also very

different from them. Restoring the proper piece of the

landscape puzzle is the best way to improve the ecology of

the site so it interacts best with surrounding areas. Photo

by Hans Riekerk

Corridors

Many intact, relatively unaltered ecosystems

have been reduced in size or fragmented due to

various human development activities. These smaller

fragments often are not large enough to support

larger wildlife species. However, these fragments

can be connected with corridors that are ribbons of

Chapter 8: Enriching and Managing Urban Forests for Wildlife 8

suitable habitat for specific species connecting larger

habitat blocks. This connection effectively increases

the total size of the remnant ecosystem and its ability

to maintain sizable wildlife populations (Figure 14).

Genetic variation is maintained because genetic

material is carried freely through the corridor and

among large habitat blocks by dispersing wildlife.

Scattered animals also can use corridors to

recolonize areas that have suffered from local

extinctions. Corridor width is the most important

variable affecting its function. Wider strips are more

valuable than narrow ones. For more information on

corridors and ecological connectivity, see Chapter 3

- Biodiversity.

Figure 14. Corridors may connect ecosystem fragments

and provide suitable habitat for some species. Photo by

Henry Gholz

Edge Effects

One obvious characteristic of urban forests is the

sharp contrast between various land uses/vegetation

on these sites. Many human-made, sharp edges or

borders between vegetation types are found in this

type of landscape. These sharp edges cause many

problems for wildlife and their habitats.

Human-modified areas surrounding a forest fragment

are usually altered into earlier successional stages

(Figure 15).

Figure 15. Human-made sharp edges or borders between

vegetation cause many problems for wildlife and their

habitat.

These areas are attractive to pioneering species

that invade several hundred meters into the adjacent

forest fragment and alter the plant species

composition and relative abundance which in turn

affects the suitability of the habitat for various

wildlife species. Along forest edges, avian brood

parasites (cowbirds), nest predators (small

mammals, grackles, jays, and crows), and non-native

nest hole competitors (e.g., starlings) are usually

abundant. Cowbirds feed in open areas and lays their

eggs in other species' nests found along forest edges.

Many birds cannot distinguish this foreign egg from

their own and devote all of their energy to raising the

young cowbirds. The eggs of the host species are

either removed by the adult cowbird or are pushed

out of the nest by the more aggressive cowbird

nestling. The result is cowbird numbers increase at

the expense of the host species (Figure 16).

A field-forest edge also attracts a variety of

open-nesting birds, but such an edge functions as an

"ecological trap." Birds nesting near the edge

usually have smaller clutches and are more subject to

higher rates of predation and cowbird parasitism than

those nesting in either adjoining habitats

(Brittingham and Temple 1983). A general principle

Chapter 8: Enriching and Managing Urban Forests for Wildlife 9

Figure 16. Along forest edges, avian brood parasites are

usually abundant; here a cowbird has laid its eggs in a

thrushs nest.

is that the greater the contrast between adjacent

vegetation types, the greater the edge effect.

Noise associated with construction, operation,

and maintenance of developments can cause harmful

impacts on wildlife. Animals that rely on their

hearing for courtship and mating behavior, prey

location, predator detection, homing, etc., will be

more threatened by increased noise than will species

that use other sensory modalities. However, due to

the complex interrelationships that exist among all

the organisms in an ecosystem, direct interference

with one species will indirectly affect many others.

Any forest tract has a "core area" that is

relatively immune to deleterious edge effects and is

always far smaller than the total area of the forest

(Figure 17). Relatively round forest tracts with small

edge-to-interior ratios would thus be more secure,

whereas thin, elongated forests (such as those along

unbuffered riparian strips) may have very little or no

core area and would be highly vulnerable to negative

edge effects.

Figure 17. Any forest fragment has a core area relatively

unaltered by deleterious edge effects.

Edge effects have been shown to negatively

impact wildlife species within at least 300 feet of

forest boundaries (Janzen 1986, Wilcove et al. 1986).

Studies of nature reserve boundaries have provided

data that support the need for buffer zones of

decreasing use outside reserve boundary (Adams and

Dove 1989) (Figure 18). The core of these areas

must be protected from cats, dogs, human activities,

noise, predators, exotic competitors, parasitism and

other detrimental effects of development.

Figure 18. The core area of a fragmented forest may be

protected by the use of buffer zones.

Connection of Wetlands and Uplands

Wetlands are ecosystems that are periodically

inundated with water. They perform many functions

including flood control, water quality enhancement,

water supply, nutrient cycling, and good habitat for

many species (Figures 19 and 20). Most species of

birds, mammals, reptiles and amphibians feed or

breed in wetlands but also need access to surrounding

uplands to fulfill all of their life-sustaining

requirements. For example, aquatic turtles spend

most of their time feeding on plants and animals in

the water. However, one day each year, the female

must travel out of the water and find relatively sandy

upland soil to dig holes and lay eggs. Some of these

animals that move back and forth between wetland

Chapter 8: Enriching and Managing Urban Forests for Wildlife 10

and upland areas become food for upland animals,

adding both energy and organic matter to the upland

community. Surface runoff then carries some of the

organic material back into the wetlands. The

preservation or restoration of linkages between

uplands and wetlands is essential for preserving and

enhancing the structure and function of both systems.

Figure 19. Most species of birds, mammals, reptiles and

amphibians feed or breed in wetlands but also need

access to surrounding uplands to fulfill all of their

life-sustaining requirements. This wetland, for instance,

has no upland connection.

Figure 20. This wetland has good upland connections,

essential to most species of birds, mammals, reptiles and

amphibians to fulfill all of their life-sustaining requirements.

Stocking Species

Wildlife are stocked or transplanted in a number

of situations. Recovery plans for some species in

danger of becoming extinct include captive breeding

programs that include releasing the offspring into

suitable habitat areas. Game farms raise quail,

pheasant and other animals and release or stock them

in areas for hunters. Sometimes, animals living on a

proposed construction site may be removed and

transplanted to an area not slated for development.

Other stocking situations involve live-trapping

animals that are causing damage or nuisances and

releasing them in areas far away from the site of

infraction. The condition of the receiving habitat is

an important consideration in all cases. If the habitat

is evaluated as suitable, then you must answer the

question, why is the species not already present in

sufficient quantities?

The consequences of stocking species are

extremely complex. Many wildlife species can carry

dozens of diseases. Unless they are tested and found

to be disease free, introducing individuals into a new

area might enhance the spread of diseases (Figure

21). Also, new animals in an area can raise numbers

above carrying capacity (the number of animals that

can be supported by the areas resources).

Figure 21. The consequences of stocking are extremely

complex. Many wildlife species, such as this gopher

tortoise, might spread diseases if introduced to a new

area. Photo by Larry Korhnak

Managing People and Pets

Some wildlife adapt to increased human

activities in urban environments, but others do not.

Human-caused sounds, such as lawnmowers,

leaf-blowers, cars and trucks, and radios, may

interfere with important wildlife communications.

Many species are not tolerant of and will not live in

areas with high noise levels.

Education is the preferred method to manage

people. The goal of these educational programs

should be to change the behavior of people within

different target audiences so their activities are more

compatible with the wildlife management plans.

People who use the site or affect the site by their

Chapter 8: Enriching and Managing Urban Forests for Wildlife 11

activities need to understand the consequences of

their existing behavior and what they need to do to

become less damaging members of their ecosystem.

Predation and harassment of wildlife by

free-ranging domestic cats and dogs are other

challenges in urban ecosystems (Figure 22).

Figure 22. Predation and harassment of wildlife by

free-ranging domestic cats and dogs are a challenge in

urban ecosystems. Photo by Larry Korhnak

Cats can be especially devastating to ground

feeding and ground breeding species. Hunting is a

feline instinct, and predation rates are not related to

hunger. One study reported that a single cat, which

regularly consumed domestic food, killed over 1,600

mammals and 60 birds in Michigan during an

18-month period (Bradt 1949). Domestic cat

predation has extirpated and endangered several bird

and mammal species and populations (Humphrey

and Barbour 1981; Gore and Schaefer 1993).

Another study concluded that domestic cats were

killing about 39 million birds in Wisconsin each year

(Coleman and Temple 1996).

Management of people and pets may include

restricting use of some areas where sensitive species

may live and educational programs informing people

of the detrimental impacts of free-ranging pets.

Monitoring and Evaluating

Changes in wildlife use of the site should be

monitored at least annually during the growing and

breeding seasons. Use the same methods that you did

for the baseline surveys. Winter surveys of

migratory species using the site are also

recommended. Continue to compare these data to

lists of species that have been documented to occur

in the same ecosystems within the same geographic

range. A chart comparing the number of wildlife

species found on the site (y-axis) with time (x-axis)

will illustrate the success of your project (Figure 23).

Figure 23. Comparing the number of wildlife species

found in an area during several years will help illustrate

progress toward restoring wildlife.

Revising the Plan

Annual meetings should be held to discuss the

results of the surveys and other pertinent

information. If progress toward achieving stated

goals is satisfactory, continue as planned. If results

are not acceptable, decisions should be made for

revising the methods. Project managers also need to

be able to adapt to unexpected events, such as

damaging storms that may alter original management

plans (Figure 24).

Figure 24. Annual meetings should be held to discuss the

results of the surveys and other pertinent information.

Photo by Larry Korhnak

Chapter 8: Enriching and Managing Urban Forests for Wildlife 12

Suggested Readings

Allison, J. 1991. Water in the Garden. Little

Brown & Co., New York, NY 10020.

Butts, D., J. Hinton, C. Watson, K. Langeland,

D. Hall, and M. Kane. 1991. Aquascaping: Planting

and Maintenance. Cooperative Extension Service

Circular 912, IFAS, University of Florida,

Gainesville, FL 32611.

Cerulean, S., C. Botha, and D. Legare. 1986.

Planting a Refuge for Wildlife. Florida Fish and

Wildlife Conservation Commission, Tallahassee, FL

32399.

Dennis, J. V. 1985. The Wildlife Gardener.

Alfred. A. Knopf, New York, NY 10022.

Martin, A. C., H. S. Zim, and A. L. Nelson.

1951. American Wildlife & Plants: A Guide to

Wildlife Food Habits. Dover Publications, Inc., New

York, NY 10022.

National Audubon Society Field Guide Series.

Publisher: Chanticleer Press, Inc., New York, NY

10012. Includes: Birds (Eastern Region), Birds

(Western Region), Butterflies, Mammals, Reptiles

and Amphibians, Trees (Eastern Region), Trees

(Western Region), Wildflowers (Eastern Region),

and Wildflowers (Western Region).

Ortho Books. 1988. Garden Pools & Fountains.

Ortho Books, Sanfrancisco, CA 94104.

Schaefer, J. and G. Tanner. 1998. Landscaping

for Floridas Wildlife: Re-creating Native Ecosystems

in Your Yard. University Press of Florida,

Gainesville, FL 32611.

The Golden Field Guide Series. Publisher:

Golden Press, c/o Western Publishing Company,

Racine, WI 53404. Includes: Birds of North

America, Trees of North America, Amphibians of

North America, and Reptiles of North America.

The Golden Nature Guide Series. Publisher:

Golden Press, c/o Western Publishing Company,

Racine, WI 53404. Includes: Golden Guide to Pond

Life, Golden Guide to Butterflies and Moths, Golden

Guide to Birds, Golden Guide to Trees, Golden

Guide to Reptiles, and Golden Guide to Mammals.

The Peterson Field Guide Series. Publisher:

Houghton Mifflin Company, Boston, MA 02116.

Includes: A Field Guide to Birds, A Field Guide to

Butterflies, A Field Guide to Mammals, A Field

Guide to Animal Tracks, A Field Guide to Bird

Nests, and A Field Guide to Reptiles and

Amphibians.

Xerxes Society. 1990. Butterfly Gardening.

Sierra Club Books, San Francisco, CA 94104.

Cited Literature

Adams, L. W. and L. E. Dove. 1989. Wildlife

reserves and corridors in the urban environment: a

guide to ecological landscape planning and resource

conservation. National Institute for Urban Wildlife,

Columbia, 91.

Bradt, G. W. 1949. Farm cat as a predator.

Michigan Conservation 18:23-25.

Brittingham, M. C. and S. A. Temple. 1983.

Have cowbirds caused forest songbirds to decline?

Bio Science 33:31-35.

Coleman, J. S. and S. A. Temple. 1993. On the

prowl. Wisconsin Natural Resources 20:4-8.

Gore, J. A. and T. L. Schaefer. 1993. Cats,

condominiums and conservation of the Santa Rosa

beach mouse. Abstracts of papers presented. Annual

Meeting of the Society for Conservation, Tucson.

Humphrey, S. R. and D. B. Barbour. 1981.

Status and habitat of three subspecies of Peromyscus

polionotus in Florida. Journal of Mammalogy

62:840-844.

Janzen, D. H. 1986. The eternal external threat.

Pages 286-303 in M. E. Soul. (ed.), Conservation

Biology: the science of scarcity and diversity.

Sinauer Associates, Sunderland, 584.

Nowak, R.M., Paradiso, J.L. 1983. Walker's

Mammals of the World. The Johns Hopkins

University Press, Baltimore, 1065-1066.

Wilcove, D. S., C. H. McLellan, and A. P.

Dobson. 1986. Habitat fragmentation in the

temperate zone. Pages 237-56 in M. E. Soule (ed.),

Chapter 8: Enriching and Managing Urban Forests for Wildlife 13

Conservation Biology: the science of scarcity and

diversity. Sinauer Associates, Sunderland, 584.

Young, H. 1951. Territorial behavior of the

Eastern Robin. Proceedings of the Linnaean Society

of New York 58-62: 1-37.

Chapter 8: Enriching and Managing Urban Forests for Wildlife 14

Appendix 1. Site Evaluation Checklist -- This checklist can be used to determine the ecological value and site suitability for

certain species at any urban site.

COMPONENTS POINTS

FOOD COMPONENTS Point Values

1. Butterfly plants (Choose one from both nectar and larvae categories)

1 species of nectar plants 2 pts

2-5 species of recommended nectar plants 4 pts

> 5 species of recommended nectar plants 5 pts

Recommended larvae plants for 1 species of butterfly 3 pts

Recommended larvae plants for 2-5 species of butterfly 4 pts

Recommended larvae plants for > 5 species of butterfly 5 pts

Total (of maximum possible 10 pts) __ pts

2. Hummingbird plants (Choose one)

1 species of recommended nectar plants 2 pts

2-5 species of recommended nectar plants 5 pts

> 5 species of recommended nectar plants 10 pts

Total (of maximum possible 10 pts) __ pts

3. Native plants (Choose one from each of the 2 following groups)

1 species of recommended native plants 1 pt

2-5 species of recommended native plants 3 pts

> 5 species of recommended native plants 5 pts

Recommended plants from 1 category (grasses, grasslikes, herbaceous, vines, small

shrubs, tall shrubs, small trees, large trees)

1 pt

Recommended plants from 2-3 categories (grasses, grasslikes, herbaceous, vines,

small shrubs, tall shrubs, small trees, large trees)

3 pts

Recommended plants from >4 categories (grasses, grasslikes, herbaceous, vines,

small shrubs, tall shrubs, small trees, large trees)

5 pts

Total (of maximum possible 10 pts) __ pts

4. Bird feeders (Choose one)

1 feeder without black oil sunflower seeds 2 pts

1 feeder with black oil sunflower seeds 5 pts

Chapter 8: Enriching and Managing Urban Forests for Wildlife 15

Appendix 1. Site Evaluation Checklist -- This checklist can be used to determine the ecological value and site suitability for

certain species at any urban site.

COMPONENTS POINTS

>1 feeder without black oil sunflower seeds 3 pts

>1 feeder with black oil sunflower seeds 10 pts

Total (of maximum possible 10 pts) __ pts

COVER COMPONENTS

1. Bird houses (Choose one; numbers of houses are for each half acre or half of a soccer field)

1 house of recommended specifications for 1 species 1 pt

2-3 houses of recommended specifications for 1 species 3 pts

>3 houses of recommended specifications for 1 species 4 pts

2-3 houses of recommended specifications for 2-3 species 6 pts

>3 houses of recommended specifications for 2-3 species 7 pts

>3 houses of recommended specifications for >3 species 10 pts

Total (of maximum possible 10 pts) __ pts

2. Treefrog houses (Choose one; numbers of houses are for each half acre)

1 house in appropriate location 3 pts

2-5 houses in appropriate locations 7 pts

>5 houses in appropriate locations 10 pts

Total (of maximum possible 10 pts) __ pts

3. Bat houses (Choose one)

1 house of recommended specifications and placement per half acre 5 pts

>1 house of recommended specifications and placement per half acre 10 pts

Total (of maximum possible 10 pts) __ pts

4. Vertical dead trees (Choose one; at least 1 foot in diameter and 10 feet high)

1 per acre 5 pts

2 per acre 7 pts

3 per acre 10 pts

Total (of maximum possible 10 pts) __ pts

5. Burrows (Choose one from each of the 3 following groups)

4 inch diameter opening 3 pts

> 4 inch diameter opening 4 pts

Chapter 8: Enriching and Managing Urban Forests for Wildlife 16

Appendix 1. Site Evaluation Checklist -- This checklist can be used to determine the ecological value and site suitability for

certain species at any urban site.

COMPONENTS POINTS

Depth of 1-3 feet 3 pts

Depth > 3 feet 4 pts

Vegetation at least 1 foot tall within 1 foot of entrance 2 pts

Total (of maximum possible 10 pts) __ pts

6. Brush piles (Choose one)

1 brush pile 5 pts

> 1 brush piles 10 pts

Total (of maximum possible 10 pts) __ pts

7. Rock piles (Choose one)

1 rock pile 5 pts

> 1 rock piles 10 pts

Total (of maximum possible 10 pts) __ pts

WATER COMPONENTS (Choose one only if it contains water for at least 1 month)

Above ground bird bath(s) 2 pts

On ground, < 3 inches deep bird bath(s) 3 pts

Installed pond with steep sides and no areas < 3 inches deep 3 pts

Installed pond with sloping sides and some areas < 3 inches deep 4 pts

Installed pond with marsh or swamp plants from recommended list 5 pts

Installed pond with marsh or swamp plants from recommended list and connected to a

restored or natural upland area 6 pts

Natural body of water (pond, lake, stream, or river) with native marsh or swamp plants 8 pts

Natural body of water with native marsh or swamp plants and connected to a restored or

natural upland area

10 pts

Total (of maximum possible 10 pts) __ pts

SPACE COMPONENTS

1. Size of Site (Choose one)

Less than 1 acre 1 pts

1 to 5 acres 2 pts

5 to 10 acres 3 pts

Chapter 8: Enriching and Managing Urban Forests for Wildlife 17

Appendix 1. Site Evaluation Checklist -- This checklist can be used to determine the ecological value and site suitability for

certain species at any urban site.

COMPONENTS POINTS

10 to 20 acres 4 pts

20 to 50 acres 5 pts

50 to 100 acres 6 pts

100 to 500 acres 7 pts

500 to 1000 acres 8 pts

1000 to 5000 acres 9 pts

more than 5000 acres 10 pts

Total (of maximum possible 10 pts) __ pts

2. Connected to > 1 acre of good habitats on adjacent properties

Yes 10 pts

Total (of maximum possible 10 pts) __ pts

3. Natural succession area

Natural succession area set aside as recommended 10 pts

Total (of maximum possible 10 pts) __ pts

4. Annually mowed area

Annually mowed area set aside and maintained as recommended 10 pts

Total (of maximum possible 10 pts) __ pts

Grand Total (of maximum possible 160 pts) __ pts

Chapter 9: Invasive Plants and the Restoration of the

Urban Forest Ecosystem1

Hallie Dozier2

1. This is Chapter 9 in SW-140, "Restoring the Urban Forest Ecosystem", a CD-ROM (M.L. Duryea, E. Kampf Binelli, and L.V. Korhnak, Eds.) produced by

the School of Forest Resources and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of

Florida. Publication date: June 2000. Please visit the EDIS Web site at http://edis.ifas.ufl.edu

2. Hallie Dozier, Forest Ecologist, 13213 Briar Hollow, Baton Rouge, LA 70810.

The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational

information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.

For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative

Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

Abstract

Many ornamental species spread from gardens

to natural areas where we do not welcome them.

These plants out of place, or weeds, threaten the

integrity of our natural systems. As gardeners we

demand access to thousands of exotic species,

unaware of side effects some have on natural

systems. The tale of public expectation of gardening

choice and variety began centuries ago. Early

colonists worried mostly about food security, but

from 1700 to the early 1900s Americans witnessed

extensive plant exploration and introductions.

Technological advances facilitated the change, as did

growing public interest in gardening and growing

prosperity found in nursery trade. Early colonists

introduced invaders such as Scotch broom and

common privet. Later explorers brought in other

ornamentals-turned-invaders including China-berry

and Norway maple. Welcoming non-native species

into our landscapes for centuries has created a

multi-billion dollar ornamental plant industry and a

gardening public that takes this largesse for granted,

selecting primarily on basis of color, shape, and size.

Today's public is unaware of the origins of most

ornamental plants and of the danger some species

pose to natural areas.

Introduction

Today conservationists are concerned about the

impacts invasive non-native plants have on our

natural landscapes. In North America, thousands of

non-native plant species succeed outside the confines

of cultivation (Randall and Marinelli 1996), that is,

they have naturalized. Most naturalized species are

not thought to harm or disrupt the ecosystems where

they are found, however, in roughly 300 cases,

naturalized plant species have had a demonstrably

negative effect in urban and rural natural areas - they

have become invasive (Marinelli 1996). Invasive

plant species can have direct impacts on natural

areas, when they form monocultures, exclude native

plants or change ecosystem functions. These changes

may, in turn, cause indirect changes to ecosystem

processes (c.f. Center et al. 1991; D'Antonio and

Vitousek 1992; Mooney and Drake 1986). Of the

recognized plant invaders introduced in North

America, deliberately and accidentally, over the last

500 years, roughly half were brought in for

ornamental purposes (Marinelli 1996). Species that

have become invasive include every plant form and

they vary in site requirements. They differ in degree

of aggressiveness; some take over soon after

introduction while others slowly build their

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 2

populations to a critical mass after which they

quickly expand into a full-blown invasion (Usher

1988). Spread may be cosmopolitan, affecting

similar ecosystems throughout a latitudinal band, or

spread may be somewhat limited in range. In North

America most invaders are terrestrial herbaceous

species, though many are woody (Center et al.

1991), and still others thrive in waterways (Nelson

and Richards 1994). Urban forest managers should

be concerned about biological invasions for two

reasons: 1) urban parks and natural areas may be

especially vulnerable to invasion because of high

levels of use (disturbance) and close proximity to

ornamental plantings; and 2) urban areas, with heavy

concentrations of ornamental plantings and

potentially heavily infested natural areas may serve

as jumping off points for invasion into natural

areas.

Although existing infestations remain to be

dealt with and pose managers considerable

challenges, it would be of tremendous benefit if the

movers of plant materials (e.g., landscapers and

home gardeners) were more discerning in selecting

the plant materials they put into the landscape. Many

people, however, even environmentally sympathetic

people and experienced gardeners, have little

information that would allow discerning plant

selection, such as knowledge of a plant's range of

origin or potential to be invasive (Colton and Alpert

1998; Dozier 1999). Moreover, though interested in

the topic, people generally are unaware of and do not

understand the issue of biological invasions, either

plant or animal (Colton and Alpert 1998). Among

gardeners and landscapers, though, the public

traditionally has been better informed. History

reveals that our knowledge of landscaping plants has

changed since the time when botanical introductions

were a topic of intense public interest and discussion.

Today, the variety of plants we have seems a matter

of course (see History Section) to many gardeners

whose interest has shifted from the full story of the

plant and how it came to our shores to a more

functional interest, that is, how a particular plant

performs in terms of color, shape, texture and growth

potential (Figure 1).

We have, as gardeners, become accustomed to

having a tremendous variety of species from all over

the world at our disposal, and restricting ourselves to

using only native ornamental species would

eliminate nine in ten of our most common landscape

species (Van de Water 1995), that is, most of our

manipulated landscapes are comprised of non-native

species. When one of these species becomes

invasive we must ask ourselves what are the

ecological results of biological invasions? How

should we manage invaded sites? How can we

prevent future invasions? This chapter discusses the

ecology of plant invasions, some general approaches

to managing these invasions, and offers suggestions

for approaching education efforts regarding

invasions. Further, it briefly describes the history of

ornamental plants with particular attention to species

that have subsequently become invasive.

Figure 1.1

Ecology of Invasions

Definitions

It is important to define commonly used terms

before discussing plant invasions. They are:

Weed - a plant out of place.

Exotic - not native to place where found.

Typically we consider exotics to be those plants that

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 3

Figure 1.2

Figure 1.3

Figure 1.4

Figure 1. Classic non-native landscape choices such as

this camellia (1.1), hydrangea (1.2), impatiens (1.3) and

lantana (1.4) give gardeners reliable lasting color and

interesting textures and shapes.

came to North America with Europeans after 1500

(FLEPPC 1999).

Colonizer - species that enter unoccupied or

sparsely occupied habitats, perhaps following major

disturbance.

Naturalize - to establish as if native, to escape

cultivation and successfully recruit to the next

generation.

Invader - invasiveness has many definitions but

the common themes are ecosystem dominance,

displacement of native species and disruption of

system functions. Invaders are:

• Species that proliferate out of control and

degrade our ecosystems, make us ill or devour

our crops (Devine 1998);

• Species that have a significant effect on native

plants and animal; species that modify habitats

extensively or those that alter ecosystem

structure or rearrange the biology of a system on

a large scale (Mooney and Drake 1986);

• Species that can establish in relatively intact

sites and come to dominate or replace the native

flora (Bazzaz 1986); and

• Species whose introduction does or is likely to

cause economic or environmental harm or harm

to human health (Office of the President 1999).

Site Invasibility

For the most part, disturbed sites are thought to

be the most vulnerable to invasion. Disrupting

natural processes in a site puts it at risk for

aggressive species to enter the system, become

established, and supplant native species (Hobbs and

Huenneke 1992). Disturbance does not only imply

vegetation clearing or soil disturbance - altered

drainage patterns, fire suppression, waste dumps, and

storm water runoff filled with fertilizers or pesticides

- are all examples of disturbances (see Chapter 4 -

Disturbances and Succession). Undisturbed sites

are rare, however, particularly in urban settings

where many invasions tend to occur in disturbed but

intact (eg., closed canopy) settings or along the

edges of such sites.

Site degradation is not the only factor

contributing to invasion: an area must be a suitable

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 4

site for the invader to succeed and there must be a

source of propagules (e.g., seeds, stems, etc.) for the

site to be compromised. In heavily landscaped urban

areas, propagules abound. Birds may deposit seeds

eaten from an invasive shrub, vine or tree in

neighboring yards, or bits of a plant may wash down

the stream after a heavy rainfall. A plant lover may

even opt to toss an unwanted plant into the wooded

lot behind the house because he or she cannot bear to

throw it on the trash heap. Depending on the species,

though, even a plant thrown on the trash heap may be

the starting point for an invasion.

Species invasiveness

Not all species are equally invasive, but invaders

often share several characteristics that give them the

advantage in a native ecosystem. They may be fast

growers, have high reproductive allocation (e.g.,

heavy flowering and fruiting), have easily dispersed

seeds and high germination rates, they may tolerate a

variety of site conditions, and they may be hard to

eradicate (Baker 1965). In other words, they are

easy to start and grow, and they are difficult to kill -

good landscape plants for urban gardens (Dozier

1999; Koller 1992).

One example of an ideal invader is the common

privet (Ligustrum vulgare L.), one of the earliest

(1500s) European arrivals in North America. In

addition to its landscape value, this multi-purpose

shrub served for dyeing, tanning, fiber, ink, and it

had medicinal applications (Haughton 1978). Until

the early 1800s it was the only privet grown in

America, but by the early 1900s this deciduous shrub,

susceptible to twig blight, had been replaced in

landscaping largely by Japanese privet (L. japonica

L.) (Figure 2) and Chinese privet (L. sinense Lour.)

(Wyman 1969).

Figure 2.1 Photo by Charles Fryling

Figure 2.2 Photo by Charles Fryling

Figure 2.3 Photo by Charles Fryling

Figure 2. Common ligustrum (2.1) was one of the earliest

introductions, brought in for its multiple uses. Together

with Chinese ligustrum (2.2) and Japanese ligustrum (2.3),

this genus has become extremely invasive in forests and

open areas across the country.

These are but three introduced privets in modern

nursery trade - where there is confusing mislabeling

among dozens of privets (Bender 1998; Brown 1945;

Odenwald and Turner 1987). Together, these three

species have become nuisance plants in natural areas

across the country from New England to Texas

(Randall and Marinelli 1996). The characteristics

that make privets the most commonly planted shrubs

in North America today translate into characteristics

that contribute to their invasiveness (Table 1).

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 5

Table 1. Landscape characteristics and invasiveness of

privets.

Landscape Worthy

Characteristics

Invasive Characteristics

Propagates easily from

seeds and cuttings

Sexual and asexual

reproduction strategies

Long flowering period,

abundant flowers

High reproductive

allocation

Abundant flowers High reproductive

allocation

Flowers attract bees High reproductive

allocation

Abundant and

conspicuous fruit

display

Appealing to dispersers

Late summer to winter

fruit display

Appealing to dispersers

Attracts wildlife and

provides habitat

Appealing to dispersers

Prunes well Tolerates above ground

damage

Evergreen (except L.

vulgare)

Continuous growth

Thrives in sun or shade Generalist habit

Grows easily in any soil Generalist habit

Tolerates difficult

conditions

Generalist habit

Moderate to fast growth

rate

Outgrows slower growing

species

Ecological Impacts of Invasion

Not all invasions are created equal, but the speed

with which ecosystem changes occur when invasive

non-native species establish populations in natural

areas is alarming (Usher 1988). In severe cases,

invaders may form monocultures and completely

exclude native species, such as has occurred with

purple loosestrife in northern wetlands (Blossy 1996;

Mal et al. 1992; Mercer 1990). In cases where rare

plants are endangered, loss (from direct competition

with invaders) is a serious impact. Loss of rare

species is not the only impact of non-native plant

invasions, however. Plant invasions may also cause

ecosystem structure to shift from herbaceous to

woody, as when Chinese tallow tree invades

southeastern coastal areas (Bruce et al. 1995). In

other cases forests may be reduced to herbaceous

systems when vines, such as kudzu (Pueraria logbata

(Willd.) Ohwi) and English ivy (Hedera helix L.)

(Figure 3), cover hectares of canopy trees (Bennett

1993; Reichard 1996a) and prevent the next

generation of trees from establishing (see Chapter 4

- Disturbances and Succession).

Figure 3.1

Figure 3.2

Figure 3. Invasive vines can smother mature forests,

preventing recruitment of seedlings to adulthood. Most

kudzu (3.1) was brought in for erosion control in the

southeast, though it has also been used as an ornamental

species. English ivy (3.2), introduced before 1750, invades

mature forests in the Pacific Northwest and is easy to

propagate as a house or garden plant from rooted cuttings.

Conversions in vegetation due to invasion, in

turn, drastically alter ecosystem functions when they

change hydrologic, fire or nutrient cycles (Neil 1983;

Vitousek and Walker 1989; Whisenant 1990).

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 6

Changes in plant assemblage have another effect:

Plants are the starting point for all food webs - shifts

in plant community composition affect food quality

or availability, leading to changes, beneficial and

detrimental, to the health of dependent animal

populations. Invasive plants may grow so thickly

that small mammals, for example, are effectively

screened from overhead predators, leading to a shift

in their population which, in turn, causes other

changes in the system. When changes occur over a

short period of time, it may be too rapid for other

organisms in the system to adjust.

In the southwestern United States salt cedars

(Tamarix spp.) have invaded riparian areas and

changed the composition and function of those

systems. The story of salt cedar is unique in that

managers have been working to control it for almost

half a century. This small tree was brought into the

United States early in the 19th century and used for

decoration and erosion control (Kennay 1996)

(Figure 4).

Figure 4.1

Figure 4.2 Photo by Charles Fryling

Figure 4.3 Photo by Cotton Randal

Figure 4. Salt cedars have plagued land managers for

over 50 years (4.1). Originally introduced for ornament and

erosion control, these small trees have naturalized across

the country (4.2). In the southwest they invade riparian

zones and stabilize riverbed formation, crowd out native

plants, and lower water tables (4.3).

In the Rio Grande Valley conditions that

facilitated salt cedar invasion came about from

human manipulation of the river, including flow

diversion and livestock grazing. These activities, and

the ensuing environmental degradation, set the stage

for salt cedar domination of riparian vegetation

(Taylor and McDaniel 1998). Salt cedars stabilize

river sand bars and prevent natural channel

movement. They also induce degradation by tapping

into the water table and altering natural hydrology

(Muzika and Swearingen 1997)

Natural system structures may change when

invaders such as Chinese tallow tree (Sapium

sebiferum (L.) Roxb.) arrive (Figure 5). Tallow tree,

introduced in the late 1700s, was brought here for the

practical applications it afforded - it provides an

excellent source of oil used for candle and soap

making, and it can provide shade under harsh

conditions, like those in a farm's chicken yard (hence

a regional name "chicken tree"). During the

expansion of the petroleum industrial complexes

near Houston, Texas during WWII, landscape experts

recommended this fast-growing tree to give quick

shade and reliable fall color to the new subdivisions

that sprang up near refineries (J. Griffith, Louisiana

State University, 1999, personal communication).

These refinery towns are located in the Gulf Coastal

Prairie - the remnants of which today are seriously

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 7

threatened by Chinese tallow invasion (NWRC

1999). Chinese tallow tree's impact in this area and

elsewhere has been to convert grasslands to forest, a

structural change that also affects function. For

example, natural fire regimes change because tallow

tree burns less easily than native grasses, it shades

out natives, and rapid breakdown of its leaves is

believed to alter soil solution composition,

contributing to faster eutrophication of wet systems

where it grows (Cameron and Spencer 1989). Its

leaves also release tannins which have a negative

impact on some invertebrate populations (Cameron

and LaPoint 1978). This species is not restricted to

wet sites, though, it also invades upland sites (F.

Lorenzo, Southern University, 1999, personal

communication). After centuries of cultivation and

improvement in its native Asia, this species is

essentially pest-free (Jubinsky 1995). Worse yet, it

also sprouts vigorously after cutting and is a prolific

seeder with high germination success, making

management extremely challenging.

Figure 5.1

Figure 5.2

Figure 5. Chinese tallow tree (5.1) invasions convert

grasslands to forests, changing landscape structure and

shading out natives (5.2). It continues to be a popular

landscape plant in the southeast, due to its reliable,

brilliant fall color.

Management: Technical

How do we handle current invasions and how

can we prevent future invasions from occurring?

Managing invasions can be prohibitively expensive

(MacDonald and Wissel 1989; Taylor and McDaniel

1998), therefore managers must carefully decide

which invasions to tackle, weighing cost, feasibility

and likelihood of success. Using volunteers may

make management and control more practical when

otherwise it would be too costly (Bradley 1988).

Using a mixed approach that employs chemical and

mechanical methods may be the best means of

insuring long-term success (Dozier et al. 1998), but

to do so, it is helpful to understand some critical

aspects of the invasive species' life history (e.g.,

ability to coppice, reproductive strategies, response

to herbicides, etc.). Several volumes have been

published that are instructive to managers seeking to

control a variety of invasive species, including those

introduced for ornamental purposes (see Suggested

Readings and Other Information).

Chemical Control

The key to long-term chemical management of

perennial weeds is to deliver a lethal dose of the

appropriate chemical to the underground tissues.

Translocatable herbicides follow the movement of

photosynthates, that is, sugars manufactured during

photosynthesis. It is essential, therefore, to time

herbicide application to coincide with movement of

photosynthates to storage organs so the herbicide is

transmitted to a plant's underground tissues.

Technical parameters determining management

success of invasive species include type of herbicide

used, strength, and number of applications. While

source/sink movement is the main physiological

parameter affecting chemical management success,

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 8

others include leaf developmental stage and point of

delivery. Careful consideration of environmental

conditions and an understanding how these

conditions affect physiological parameters of the

invader are also important for successful control

(Dozier et al. 1998). For example, some species may

require multiple applications to inhibit regrowth

from hard-to-kill underground tissues.

Developmental stage of an invader may

influence herbicide efficacy (Lee 1986; Willard

1988), and herbicide absorption may vary with

location of contact (Townson and Butler 1990).

Physiological responses to changing environmental

conditions can affect delivery of herbicide to

underground tissue in perennial invaders and

therefore influence management success. Seasonal

changes, for example, may have an impact on

control. Periods of low rainfall, and thus low

available soil moisture, may allow for greater

concentration of herbicide in underground tissues.

Also, late summer to early fall applications, when

carbohydrates are being shunted to storage tissues,

may increase translocation to underground tissues.

Mechanical Control

In some cases mechanical methods (cutting,

mowing, uprooting, burning, etc.) are effective for

controlling an invader. Mature plants may be cut

down or whole seedlings removed. For persistent

perennial species, though, one round of treatment

usually does not suffice, and repeated physical

removal may be required to free a site of an invader.

Usually such intensive management is not practical

or affordable, though biomass reduction will result

(Gaffney 1996; Willard 1988), aiding in the

short-term recovery of the treated site.

Norway maple (Acer platanoides L.) (Figure 6)

was introduced in 1762 (Wyman 1965), and since

has naturalized across the eastern region of the

United States.

Figure 6.1

Figure 6.2

Figure 6. Norway maple successfully competes with

native maples due to greater allocation of resources to

foliar display (6.1). It is the most planted street tree in the

country, which may explain, in part, its spread in natural

areas across the nation, especially in the northeast (6.2).

One of the most commonly planted street trees

across North America, there are over 20 varieties

available in retail nurseries. Its ability to displace

native maples in natural areas may be linked to its

resource allocation to a heavy foliar display which, in

turn, enhances its shade tolerance and ability to shade

out understory vegetation (Niinemets 1998; Randall

and Marinelli 1996). The Norway Maple Removal

Experiment in the Drew University Forest Preserve

near Madison, New Jersey employs only mechanical

methods. In an effort to restore native ecology in the

forest preserve, volunteer students and faculty, and

paid grounds crews from Drew University used

machetes and chain saws to remove and girdle the

trees in January 1998. Thus far they have been able

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 9

to avoid using chemical control and are hoping that

natural regeneration will eliminate the need for

replanting native species. Ongoing monitoring

suggests that planting will be necessary to restore

native species, though large herbivores (e.g., deer)

will make replanting a special challenge.

Mechanical control alone may work best in the

early stages of invasion such as in the case of English

holly (Ilex aquafolia L.) (Figure 7). This beloved

holly of songs and holiday festivities was introduced

in the eastern United States prior to 1750, and in the

Pacific Northwest, in the 1860s (Lang et al. 1997;

Wyman 1969). In climates somewhat similar to its

native Mediterranean range, this small tree has since

naturalized in forested areas of California, Hawaii

and Oregon (USDA and NRCS 1997).

Conservationists concerned about English holly

populations developing in rare old-growth forests in

the northwest have incorporated its removal into

restoration projects that target other invasive species.

The city of Arcata, California is taking advantage of

existing restoration work in forest remnants to

remove shade tolerant English holly before the

problem gets out of hand (G. Ammerman, City of

Arcata, 1999, personal communication). With a

no-use chemical policy, all removal efforts are

manual - volunteer workers concentrate on hand

pulling young plants during Invasion Removal days.

Larger trees are rare, but each is hand dug carefully

to prevent excessive disturbance to the site. Given

the concern about protecting old-growth forests

(Reichard 1996b), Arcata's early intervention

approach to English holly is sensible, particularly in

light of the expense and difficulty managers face

when invasions expand rapidly or are ignored during

initial stages (Hiebert and Stubbendieck 1993; Hobbs

and Humphries 1995; MacDonald and Wissel 1989).

Figure 7.1

Figure 7.2

Figure 7. English holly (7.1) has begun to show up in old

growth coastal forests (7.2) where managers remove

whole seedlings and carefully excavate mature plants.

Integrated management

Reliance on a single means of control may be

prohibitively expensive or result in failure for

aggressive species. A practical approach may be to

use mechanical control followed by chemical

application. For example, a woody species that

sprouts after cutting may be cut and herbicide

immediately painted onto all cut surfaces. A species

that responds to cutting by sprouting along the length

of its surface roots may be treated with herbicide

before cutting or treated and left standing. Invasive

species also may be mechanically treated, allowed to

grow new photosynthetic tissues, and then treated

with herbicides. The benefit of this approach is that

chemicals are applied to plants which have been

weakened by drains on carbohydrate reserves (starch

allocated to new shoot growth). Additionally,

herbicide application to the flush of new plant tissues

may maximize absorption and result in greater

efficacy.

Integrated management also includes replanting

the site with suitable species, for if the space freed by

removal of the invader is not filled with another

plant, the invader may return. After suppression of

the invader, the establishment of desirable plant

species is essential for long-term control of the site

(Dozier et al. 1998; Taylor and McDaniel 1998). The

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 10

strategy should be to replace the invader, not

temporarily remove it.

An example of such integrated management is a

salt cedar removal project in New Mexico. A variety

of methods have been used over the last half century

to control salt cedar, and researchers continue to look

for the combination of techniques that yields the best

result while lowering costs. Recent restoration

research in the Bosque del Apache National Wildlife

Refuge suggests that traditional clearing (mechanical

and chemical) followed by planting native

cottonwood and black willow poles can give

excellent results (Taylor and McDaniel 1998). In

addition to the integration of traditional control

methods, that is, removal of the invader and

replanting native vegetation, a new component has

been tried in these sites: timed irrigation is used to

contribute to natural regeneration of native species

while reducing salt cedar to a minor community

component. It appears that reactivating or

mimicking natural water flow may prove essential to

long-term management of this species in riparian

systems.

Management: Social

Tastemakers

Educating the public about the benefits and

pleasures of gardening was the task of the 19th and

20th century tastemakers (see History Section). Our

challenge today is to inform people about

environmentally wise gardening as a means to

reducing biological invasions. History identifies the

groups who in the past have influenced the public to

become gardeners. They are the same as those who

are instrumental in landscaping trends today - garden

writers for popular publications (Figure 8). For the

modern media of television and radio, this group also

includes broadcast writers, producers and hosts. It

would benefit conservationists to recruit the efforts

of garden editors of top selling journals such as

Sunset Magazine, Ladies' Home Journal, Better

Homes and Gardens, and Southern Living, for each of

these popular magazines reach millions of readers

(Wissenfeld 1998) and regularly influence people's

choices of landscape plants. If the tastemakers feel

concern about this issue they will undoubtedly add

this focus to their work. Opening lines of

communication between garden writers and

biological conservationists can only improve the

quality of information reaching gardeners.

Figure 8. Many popular magazines feature gardening

articles, which may promote invasive species. This 1994

article from Southern Living touts Chinese tallow for its

superior, early, and reliable fall color - a quality missing in

many native southern trees.

Landscapers, Horticulturalists, and Nursery

Owners

Customers rely heavily on nursery and garden

center personnel for gardening advice (Safley et al.

1993), however, nursery personnel are unable to

identify the native range of most of the plants they

sell, the majority of which are not native (Dozier

1999). If ornamental horticulture and landscape

design courses touched more on this topic, students

who go on to work in the nursery or landscaping

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 11

trades would be better equipped to understand this

issue. This, in turn, would have a positive effect on

how they conduct their businesses and how they pass

on information to their customers. People also turn to

their local Cooperative Extension agents for advice.

They too, could benefit from exposure to the subject

during their training.

Community Groups

Direct observation is a powerful tool in teaching

the public about non-native invasions. In a survey of

retail nursery customers (Dozier 1999), those

familiar with invasions were most likely to know

about the invasions as a result of personal experience

with the species or personal observation. Putting

restoration work in the public eye can be a means to

teaching people about invasions.

Today several projects across the country are

tackling non-native plant invasions, and many of the

restoration projects are in high traffic, high profile

parks and preserves. Highly visible projects,

particularly those that deal with landscaping

favorites, should include interpretive materials that

clearly outline the problem in that particular site, the

breadth of the problem in general, and the

importance of restoration activities and prevention.

These messages, however, are not always easy to

convey, and project organizers must take public

sensitivity and attachment to favorite plants into

consideration. Organizers of a Chinese tallow tree

replacement campaign in Gainesville, Florida,

learned hard lessons about public reaction to tree

removal - any tree removal (Putz et al. 1999). This

well planned campaign was supported by a variety of

critical stakeholders, including local nurseries,

government officials and educators, and it provided

educational components and incentives for home

gardeners. Despite these excellent efforts, though,

press coverage of the removal of a rather large

specimen on Arbor Day (a local newspaper ran a

color photo of one of the project planners next to the

tree, chainsaw in hand) sparked critical backlash

from the public. Thoughtful planning and careful

implementation are crucial to success, but they may

not garner desired results if public sentiment is

underestimated.

A project that had better public reception was a

miconia (Miconia calvescens DC.) eradication

project in Hawaii (Loope 1996; Mesureur 1996)

which employed (with considerable effort and

expense) television broadcasts, extensive press

releases, articles in major daily and weekly

publications, and distribution of hundreds of "most

wanted" posters. The efforts were so successful, in

fact, that citizens reported previously unknown

populations to authorities allowing them to

implement early control measures. The cost was high

in terms of effort, but it resulted in a public more

attuned to the issue of non-native plant invasions and

more vigilant about personal gardening practices.

Another way to teach these lessons is through

involving community members directly in restoration

work (Bradley 1988; Devine 1998). When

volunteers or other members of the public help

remove exotics and revegetate with natives, it gives

them the opportunity to have a real impact on their

(public) natural areas. It also gives managers the

opportunity to teach participants about wiser plant

selection for their personal gardens. The physically

challenging task of grubbing out small trees and

shrubs makes a lasting impression that may influence

a person's future choices in landscape plants.

Non-native plant invasions are going to occupy

land managers for years to come. The contribution to

this problem from urban areas, in the form of

ornamental species, is considerable, and urban

managers should pay special attention to addressing

this issue. Ornamental gardening history gives us a

glimpse of how modern fashions in landscaping

developed, and suggests how best to reach the

gardening public to reshape those tastes. The

gardening public, as well as those who work in

nurseries and as landscapers, clearly can be

instrumental in stemming introduction of invasive

species; managers should concentrate on

demonstrating to these groups - directly and through

gardening tastemakers - the damage invasions cause.

There are many opportunities for teaching people

about the issue of non-native plant invasions:

popular articles (including radio and television) on

gardening, highly visible restoration projects, and

education of resource people such as nursery

personnel, landscapers and extension agents. Just as

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 12

taking advantage of these opportunities enamored

the country with ornamental gardening (See History

Section), these paths will allow us to develop into a

country of environmentally conscientious gardeners.

Wise Gardening Choices

What is the best educational message to give

those who decorate the urban landscape with

ornamental plants? It will not work simply to pass

out lists that inform people which plants are "bad."

While extremely useful, lists of invasive plants may

be difficult to compile and maintain - the lists

necessarily changing as scientists recognize more

invasions. Moreover, such lists may not indicate

exactly where a particular species is problematic

(FLEPPC 1995; FLEPPC 1999) which reduces the

list's usefulness. Nor will it work to teach people

simply to "plant natives" - most popular landscape

species are not native, and some natives can be as

aggressive and weedy, or as finicky, as non-natives.

Not only that, people may not respond well to a

simplistic approach that dictates what to plant and

what not to plant. Guilt over selecting a non-native

plant should not be a side effect of education.

A more feasible and beneficial course of action

is to teach people to gather as much information as

they can about the species they select. Learning

about landscape species gives gardeners interesting

information about the plants they use, and it will give

them the opportunity to make environmentally sound

choices in their gardening. In addition to asking for

information that will help them pick the right plant

for their landscape needs, gardeners can ask the

following:

1. What is this plant's native range?

2. How does the plant reproduce?

3. Is this a plant that needs a lot of

maintenance to keep it in check?

4. Is it an aggressive grower?

5. Does it attract birds?

6. Is it known to be invasive anywhere?

7. Is it known to be invasive in areas similar

to where I want to plant it?

Answering these questions will allow gardeners

and landscapers to have a better idea how their

choices may impact (if at all) areas outside of the site

they intend to change. This, in turn, should lead to

wiser choices on the part of gardeners and

landscapers.

History

Ornamental Plant Introduction

Our gardens are crowded with an amazing

wealth of exquisite plants both ornamental

and economic; our lawns are studded with

superb trees and shrubs satisfying in form,

color, flower, and often, fragrance; our

orchards bear fruit in such variety as to

lengthen their seasons far beyond those of

only a short time ago. Our annual crops of

garden catalogues are filled with long,

awesome lists, incredible illustrations, and

Baron Munchausen descriptions. As a result,

our minds are confused by numbers and

beauty and wearied by the labor of making

choices. Surely our notion of "bigger and

better" has run riot in gardens, their

catalogues and their books. Do we even

wonder or speculate as to how this has come

about? Or do we lazily accept the largesse?

-Ann Dorrance, 1945, p.73

Age of Function: Early Colonial

Spices and medicines derived from plants were

commodities important enough to drive the vast

world explorations conducted by 15th century

explorers (Dorrance 1945). Men and women who

settled in North America had little time for gardening

except that which was necessary to insure an

adequate supply of food, flavorings, medicines and

fiber. Naturally, they brought with them plants from

home including fruit trees and medicinal herbs

(Leighton 1986; Manks 1968; Martin 1988; van

Ravenswaay 1977; Wyman 1968) (Figure 9).

Some of the plants they brought were not native

to Europe, but adopted from other areas already

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 13

Figure 9.1

Figure 9.2

Figure 9. Early settlers brought important medicinal and

culinary herbs and food plants with them when they arrived

in North America. Tansy (9.1) has naturalized in several

states and is considered invasive in the Pacific Northwest

and elsewhere. Figs (9.2) have escaped plantations in

California's central valley to invade riparian zones (Randall

and Marinelli 1996).

explored; peaches, native to Asia, were brought here

by Spaniards in the 16th century (Crosby 1986;

Manks 1968) (Figure 10).

Figure 10.1 Photo by Larry Korhnak

Figure 10.2 Photo by Charles Fryling

Figure 10. Peaches have been in cultivation for thousands

of years (10.1 and 10.2). Native to Asia, they first came to

North America with early Spanish explorers. Adopted by

native tribes, later European settlers initially believed

peaches native to the New World.

Well into the 17th century colonials had so little

leftover from their harvests that they relied, for the

most part, on Europe for most of their goods,

including each year's seed supplies, thus regular

intercontinental transport of plant materials began

early.

Some of the plants deliberately introduced

during the 16th and 17th centuries have naturalized;

a few are considered problem species in our

landscapes today. They include Scotch broom

(Cytisus scoparius L.) (Figure 11) and common

privet (Wyman 1968; Wyman 1969).

Age of Exploration: Eighteenth &

Nineteenth Centuries

Though colonists settling into their new

environment continued to be interested primarily in

gardening for function, the 18th century was a time

of great feats of plant exploration, export and

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 14

Figure 11. Scotch broom was brought into the U.S. for

practical and ornamental purposes. Here the shrub

colonizes areas leveled by the 1992 fires near Berkeley,

CA. Photo by Susan Gabbard

introductions (Hedrick 1950; Manks 1968).

Botanists John Bartram and André Michaux, among

others, actively exchanged plant materials between

the world's continents, particularly North America,

Asia and Europe. Bartram, who became the

American botanist to King George III,

enthusiastically sent native American plants to

England in exchange for European and other species

that had performed well in Europe. Michaux also

helped populate European gardens with native North

American plants; during a ten-year period he sent

more than 60,000 live plants back to Europe

(Hedrick 1950; Manks 1968). His contributions to

North America include the China-berry tree (Melia

azedarach L.) (Figure 12), which came from Asia

via France, several popular species of azalea

(Rhododendron spp.), and crape-myrtle

(Lagerstroemia indica L.), which he introduced to

the Charleston, South Carolina area (Hedrick 1950).

The work of these two men and their contemporaries

formed the basis of our current knowledge of North

American species, and we regard them as great

visionaries for their spirited investigation and

dissemination of American natives.

Figure 12. An early introduction brought from Asia to

North America by French botanical explorer, André

Michaux, Chinaberry tree has been used extensively as a

farm tree. Though many across the southeastern states

consider it a weed tree, it is also is useful for quick shade

and fuel wood (Haughton 1978). Photo by Charles Fryling

Commercial plant trade tended to de-emphasize

the value of native plants while promoting

non-native species. Robert Prince, who established

the first commercial nursery in Flushing, New York

in 1737, mostly promoted European novelties

(Manks 1968). An early advertisement from Prince

Nursery included dozens of species of apples and

stone fruits as well as ornamental species such as

silk-tree (Albizia julibrissin Durazz.) (Figure 13),

European Snowball (Viburnum opulus L.), and tree

of heaven (Ailanthus altissima (Mill.) Swingle)

(Figure 14) (Hedrick 1950; McGourty 1968b).

Figure 13. Gardeners enjoy the mimosa, or silk tree, for its

shape, texture and fragrant pink blossoms. Introduced in

1745, this species since has become naturalized from New

York to California (USDA and NRCS 1997).

Notable introductions of the 18th century which

are with us today and which are, in some areas,

invasive, include English holly, Norway maple, a

troublesome species in northeast and northwest that

came in 1762, and English ivy (Hedera helix L.),

introduced in 1736 and now a major invader in

natural areas along the northern Pacific coast Randall

and Marinelli 1996; Wyman 1965; Wyman 1968).

Age of Adornment

By 1837 when Victoria ascended the British

throne, several events had occurred in the United

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 15

Figure 14. Another early introduction (1784), the tree of

Heaven is valued in colder regions of the country for its

tropical-looking foliage and its ability to withstand harsh

urban conditions (Wyman 1968). In the southwest, it is

appreciated for its medicinal properties (Cheatham et al.

1995). Photo by Charles Fryling

States and abroad making way for the whirlwind of

horticultural activity that continued into the 20th

century. During the short span of 100 years, global

exploration increased, international trade became less

burdensome, the number, quality and availability of

printed materials increased, and industrialism

stimulated a prosperity that allowed the widespread

novelty of leisure time. These elements combined to

create a climate where pleasure gardening became

fashionable, accessible, affordable, and profitable.

Transportation, domestic and international,

improved dramatically during the early part of the

century. The opening of new post roads, the Erie

Canal (1825), and the Long Island Railroad (1836)

not only increased people's mobility, it facilitated

movement of gardening stock, especially by mail

order (Manks 1968). The historically famous

M'Mahon Nursery was just one of many eastern

sellers offering seeds and bulbs through the mail.

Early in the century, most plants were brought in

by botanical explorers, who commonly were

sponsored by wealthy patrons and botanical clubs.

With improvements in oceanic transit, world travel

became more common, and commercial nursery

owners interested in obtaining new or rare plants by a

faster route appealed directly to travelers to carry

home starting stock (Manks 1968).

Improved transatlantic travel had another impact

on gardening in the United States as well: one

upmanship. With increasing numbers of Americans

traveling to Europe and Europeans traveling to the

United States, a competition grew up between the

two continents, especially in the highly visible areas

of economy, social politics, and horticulture.

Europeans wrote prolifically about inferior American

landscapes and Americans shared with each other

impressions of beautiful and extensive European

gardens. According to 19th century horticulture

historian, Tovah Martin (1988), the situation for

Americans was not unlike Adam and Eve discovering

their nakedness, "The shame...was infinitely

confounded by the realization that the rest of the

world was clothed" (p. 51).

Newfound prosperity from industrialism

allowed Americans the leisure time to indulge in

horticulture as a pastime. This was especially true for

girls and women who used botanical pursuits as a

socially acceptable way to express themselves

intellectually and artistically (Martin 1988). Leisure

time also allowed for pleasure reading, and by the

1830s gardening magazines were common, including

those that featured articles describing tropical regions

of the world, where plant hunters busied themselves

collecting ever new and interesting specimens for

return to the United States. Authors wrote articles

specifically to educate and entertain a public eager

for sophistication and to encourage the American

public to become enamored with pleasure gardening.

These articles also served as a way to bring the exotic

world into the homes of everyday Americans.

Throughout the century, gardening advocates

inundated the press, garden clubs and speech circuits

with encouragement for fledgling gardeners (Martin

1988). They were the "tastemakers of the times

[who] saw their tasks primarily as a battle against

widespread ignorance," and thus, from the 1830s

onward, "Americans were subjected to an onslaught

of consciousness raising publicity aimed at educating

the masses about the pleasures of ornamental

gardening." To ensure that citizens did not forsake

these new pleasures and return to their traditionally

puritan ways, they were "continually coached by

vigilant gardening advocates" (p. 52).

Nursery owners joined others in promoting

pleasure gardening to an increasingly interested

public. A growing number of gardening journals

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 16

provided readers with detailed instruction on how to

plant and care for the variety of plants becoming

available across the country. Many of the guides

were written, edited, and published by large nurseries

and seed houses. Nurseries and seed houses also

frequently financed gardening books. With the

sponsorship of nursery and seed house owners,

Edward Sayers published three editions of The

American Flower Garden Companion (1838). Such

publications also served commercial nursery owners

as advertisements - most consumers preferred getting

their gardening advice from experts. One publisher

unfortunately promoted his book with claims of

objectivity, for he had no connection to any nursery,

and made such a poor impression that his magazine

failed in its first year (Hedrick 1950).

Over the century, the popular press continued to

bring the thrills and excitement of plant exploration

into American homes. The ongoing adventures of

botanical explorer Robert Fortune in China were

published, in serial form, in the influential

horticultural journal, The Horticulturist and Journal

of Rural Art and Rural Taste (1846-1852), edited by

premier landscape architect, A.J. Downing. Other

publications provided subscribers with colorful

accounts of jungle treks in many far away places,

sometimes including detailed illustrations of exotic

queens and kings to captivate the American reader

(Martin 1988).

Independent horticulture societies (the first was

established in New York in 1818) began appearing in

addition to those that had branched from larger, older

agricultural societies formed during the previous

century (Hedrick 1950). These clubs, which

frequently relied on the support of wealthy,

horticulturally inclinded community leaders, began

to encourage nursery owners to import and develop

more and more ornamental specimens (Manks 1968).

In 1827, President John Adams made an official

request to foreign consuls to send seeds and

specimens of rare plants back to Washington for later

circulation, beginning a long period of

government-sanctioned plant introductions that

continues today (Wyman 1968).

Mid-century found America's obsession with

non-native plants widespread and unstoppable (van

Ravenswaay 1977). Lawns which had been

dominated by lush green were now neatly trimmed

with newly developed lawn mowers. Gardens

featured a variety of color from easily available,

tender (e.g., cold sensitive), tropical plants brought

to North America in Wardian Cases (Figure 15) and

raised in larger, improved glass houses (Figure 16).

Figure 15. English botanist Nathaniel Bagshaw Ward (b.

1791 d. 1868) found a way to defeat lethal salt water and

sea spray that commonly decimated entire live cargoes

when, in 1832, he successfully shipped live seedlings from

England to Australia in closed, glazed glass cases -

changing forever the business of plant import (Dorrance

1945).

Figure 16.1 Photo by Charles Fryling

The trend of using tropicals as bedding plants,

which clearly allowed for the continuous

introduction and sale of new plant material,

continues today (Figure 17).

Writers in the 1860s continued urging

Americans to adorn their estates with color and

bloom. Those who actively promoted gardening

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 17

Figure 16.2 Photo by Charles Fryling

Figure 16. By the 1840s, glass making had improved

greatly and manufacturing techniques for cast iron made it

possible to construct large, stable glasshouses for

growing every variety of plant. Pictured here, the Palm

House at Kew Botanical Garden in London (16.1) and the

interior of the Golden Gate Park Conservatory in San

Francisco (16.2).

Figure 17. Nineteenth century gardeners began using

cold tender tropical plants as houseplants and as warm

season annuals, practices that continue today.

believed that most Americans could benefit from

expert help in order to develop their skills as

landscape designers. To ease the transition from

novice to experienced gardener, F.J. Scott addressed

the gardening needs of average families who lived on

small (~ 1/2 acre) suburban lots. This work appealed

to a large audience and helped "induce every family"

to explore the satisfaction of gardening and raptures

of tropical plants (Martin 1988). Private homes were

not the sole domain of horticulture. For a period of

several years, A.J. Downing used his journal to

supply a steady stream of editorials in which he

implored Americans to convince their local

governments to establish and fund public parks for

pleasure and recreation (Hedrick 1950). Due to his

efforts, those who did not own their own property

where they could enjoy the physical, psychological,

and moral benefits of gardening were able to enjoy

the new urban park systems designed and developed

by men like Frederick Law Olmstead, designer of

New York City's Central Park and Boston's Emerald

Necklace (Eisner 1994), and Thomas Meehan who

spearheaded the acquisition of lands for

Philadelphia's city parks (McGourty 1968a).

Gardening for pleasure became not only vogue, it

was on its way to becoming common, and the effect

on the plant trade was enormous. Scott's continued

bombardment of the American public with articles

promoting the knowledge of gardening and the

enjoyment of using tender tropical plants as annuals

perpetuated plant introduction in two ways: nurseries

had to scramble to provide customers with a constant

source of new plants from foreign places, and they

had to continue to stimulate the demand for new

plants. Plant hunters continued outbound with the

goal of introducing new and rare specimens to the

gardening public.

Following the Civil War, which temporarily

slowed horticultural progress, the opening of the

Arnold Arboretum in Boston (1872) renewed the

stimulus for introducing non-native plants,

particularly Asian flowering shrubs (Wyman 1968).

In the late 1890s the federal government established

the Office of Plant Introductions, which facilitated a

steady stream of plants into the country (Fairchild

1928).

Hundreds of foreign plant species came into

North America during the 1800s. Some have

naturalized and persist in modern landscapes,

including porcelain berry (Ampelopsis

brevipedunculata (Maxim.) Trautv.), salt cedar,

Japanese honeysuckle, coral ardisia (Ardisia crenata

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 18

Sims.) and Chinese wisteria (Wisteria sinensis

(Sims.) Sweet) (Figure 18) (Wyman 1969)

Figure 18.1

Figure 18.2

Figure 18.3

Figure 18. Both Chinese wisteria (18.1) and Japanese

honeysuckle (18.2) have long been known as aggressive

vines that escape cultivation in the eastern portion of the

United States. Almost 200 years after introduction (1804)

nandina (18.3) is making the jump from garden to natural

areas in northern Florida. Nevertheless, such old-time

ornamental species appeal to gardeners for their

fragrance, color and nostalgia (Dozier et al. In preparation).

Though the river of new plants introduced from

abroad slowed to a comparative trickle by the early

1900s, our affection for landscaping and ornamental

gardening did not. A new generation of plant

explorers grew up and horticulturalists refined the art

of breeding new varieties of well-loved species.

Botanical explorer, David Fairchild, under patronage

of Lathrop Barbour, introduced many species during

the first half of the 20th century (Fairchild 1938).

For over forty years, during most of which time he

worked as chief of the Seed and Plant Introduction

Section of the USDA (1898-1940), he collected

thousands of seeds and live plant specimens and

brought them into the United States. While Dr.

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 19

Fairchild considered the majority of species he

introduced useful (Fairchild 1928,:3-11), he usually

managed to procure several purely ornamental

species during any collection expedition (Wait 1968).

In 1918, Plant Quarantine 37 became law after

several damaging insects and diseases arrived with

new plants (Wyman 1968). While making certain

that new plants were free of insects or diseases

lowered the chances that pests harmful to economic

crops would enter the country, in some cases the

practice effectively freed new plants from their

natural controls and contributed to their invasiveness

(Jubinsky 1996; Randall 1996).

Horticultural activity slowed for most

Americans during the 1930s due to the Great

Depression, dampening nursery sales, but post-World

War II economic recovery in the late 1940s allowed

tremendous regrowth in this area. In the period

following the war, the garden center movement

developed, which, in turn, revolutionized the retail

plant industry (Schneider 1990). Homeowners soon

were able to buy directly from nurseries without

having to wait for mail order, and perhaps more

importantly, they were able to buy all their supplies -

tools, seeds, soil, fertilizer and pesticides - and obtain

gardening advice, in one convenient location.

The Twenty-First Century: So Greatly Does

Custom Prevail

Today countless images from daily newspapers,

magazines, books, films and television continue to

fuel our love for gardening. Enthusiasts can peruse

pages of colorful photographic layouts and articles

listing the multiple advantages of different plants, or

they can wander about any of over 400 beautifully

tended botanical gardens (B. Boom, New York

Botanical Garden, 1997, personal communication)

filled with flowering specialties from around the

globe (Figure 19).

Figure 19. Botanical gardens perform many services,

including educating the public about the world of plants. A

future path for botanical gardens and arboreta may be to

take a lead role in educating people about biological

invasions and the importance of preserving biodiversity.

Across the country, it is difficult to find a county

that does not have at least one plant nursery, there is

no postal route that does not carry seed and plant

catalogues into homes, and most bookstores feature a

whole class of gardening books. Most sizable towns

boast gardening/horticulture societies as well,

providing a venue for people to share their knowledge

and passion for plants. In the absence of nurseries,

large discount retail stores often have garden centers

attached, and in the absence of book retailers and

gardening clubs, gardeners can get information and

advice from the World Wide Web. In addition,

many television and radio stations broadcast

gardening shows. The efforts of book and journal

publishers, film, radio and television producers, and

garden patrons continue to provide huge rewards for

the nursery industry. The supply side of this well

developed supply/demand relationship represents a

minimum of $2.5 billion in annual wholesale trade

(potted flowering, foliage or house, and bedding

plants) (USDA 1996) (Figure 20).

Figure 20.1

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 20

Figure 20.2

Figure 20. Landscape, house and annual plants are worth

billions of dollars in trade every year. Indian azaleas

(2031) and gardenias (20.2), both introduced species, are

well behaved in the landscape - staying exactly where the

gardener puts them.

Suggested Readings and Other

Information

Managers can find more information for

identifying and controlling specific weeds from a

variety of sources.

Books

Invasive Plants: Weeds of the Global Garden -

by John Randall (1996)

Identification and Biology of Non-native Plants

in Florida's Natural Areas by Ken Langland and

Kathy Craddock Burks (1998)

The Southern Living Gardening Book - by Steve

Bender (1994)

The Sunset National Garden Book - by Lang et

al. (1997)

Weed Handbook available from the Wyoming

Weed and Pest Council

Private organizations and public agencies

California Exotic Pest Plant Council

(CalEPPC) at http://www.caleppc.org

Florida Exotic Pest Plant Council (FLEPPC) at

http://www.fleppc.org

Pacific Northwest Exotic Pest Plant Council

(PNW-EPPC) http://www.wnps.org/eppclet.html

Southeast Exotic Pest Plant Council (SE-EPPC)

at http://webriver.com/tn-eppc/

Tennessee Exotic Pest Plant Council

(TN-EPPC) at http://webriver.com/tn-eppc/

Bureau of Land Management - in western states

Cooperative Extension Services

USDA Animal and Plant Health Inspection

Service (APHIS) at

http://www.aphis.usda.gov/ppg/weeds/

weedhome.html

Weed Science Society of America (WSSA) at

http://www.wssa.net

Cited Literature

Baker, H.G. 1965. Characteristics and modes of

origin of weeds. In The genetics of colonizing

species, edited by H. G. Baker and G. L. Stebbins.

New York: Academic Press.

Bazzaz, F.A. 1986. Life history of colonizing

plants: some demographic, genetic, and physiological

features. In Ecology of biological invasions of North

America and Hawaii, edited by H. A. Mooney and J.

A. Drake. Berlin, Germany: Springer-Verlag.

Bender, S., ed. 1998. The Southern Living

garden book. Edited by F. Gilsenan. Birmingham,

AL: Oxmoor House, Inc.

Bennett, H. 1993. Kudzu. Georgia Forestry

46:3-5.

Blossy, B. 1996. Lythrum salicaria. In Invasive

plants: Weeds of the global garden, edited by J.

Randall and J. Marinelli. Brooklyn, NY: Brooklyn

Botanic Garden.

Chapter 9: Invasive Plants and the Restoration of the Urban Forest Ecosystem 21

Bradley, J. 1988. Bringing back the bush.

Sydney, Australia: Landsdowne Press.

Brown, C.A. 1945. Louisiana Trees and Shrubs.

In Louisiana Forestry Commission Bulletin No. 1.

Baton Rouge, LA: Louisiana Forestry Commission.

Bruce, K.A., Cameron, G.N., and Harcombe,

P.A. 1995. Initiation of a new woodland type on the

Texas coastal prairie by the Chinese tallow tree

(Sapium sebiferum (L.) Roxb.). Bulletin of the

Torrey Botanical Club 122 (3):215-225.

Cameron, G.N. and LaPoint, T.W. 1978.

Effects of tannins on the decomposition of Chinese

tallow leaves by terrestrial and aquatic invertebrates.

Oecologia 32:349-366.

Cameron, G.N. and Spencer, S.R. 1989. Rapid

leaf decay and nutrient release in a Chinese tallow

forest. Oecologia 80:222-228.

Center, T.D., Doren, R.H., Hofstetter, R.L.,

Myers, R.L., and Whiteaker, L.D. 1991. Proceedings

of the symposium on exotic pest plants, Washington,

DC.

Cheatham, S., Johnston, M.C., and Marshall, L.

1995. The useful wild plants of Texas, the

southeastern and southwestern United States, the

southern plains, and northern Mexico. Austin, TX:

Useful Wild Plants.

Colton, T.F. and Alpert, P. 1998. Lack of

public awareness of biological invasions by plants.

Natural Areas Journal 18:262-266.

Crosby, A.W. 1986. Ecological imperialism:

The biological expansion of Europe, 900-1900. New

York: Cambridge University Press.

D'Antonio, C.M. and Vitousek, P.M. 1992.

Biological invasions by exotic grasses, the grass/fire

cycle, and global change. Annual Review of Ecology

and Systematics 23:63-87.

Devine, R. 1998. Non-native biological

invasions in North America. Washington, DC:

National Geographic Society.

Dorrance, A. 1945. Green cargoes. Garden

City, NY: Doubleday, Doran.

Dozier, H. 1999. Plant introductions and

invasion: History, public awareness, and the case of

Ardisia crenata. Ph.D. Dissertation, Forest

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Gainesville.

Dozier, H., Duryea, M.L., and Wolfe, E.W. In

preparation. Invasive plant environmentalism in the

Southeast: Retail nursery customer awareness,

concern and action.

Dozier, H., Gaffney, J.F., McDonald, S.K.,

Johnson, E.R.R.L., and Shilling, D.G. 1998.

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impacts and management. Weed Technology

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Agriculture. Washington, DC: David Fairchild.

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Scribner's Sons.

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1995 Most Invasive Species List.

FLEPPC. 1999. Florida Pest Plant Council's

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Exotic Pest Plant Council, 1999 [cited March 1

1999]. Available from

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technological factors influencing the management of

cogongrass (Imperata cylindrica). Ph.D. dissertation,

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Hiebert, R.D. and Stubbendieck, J. 1993.

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integrated approach to the ecology and management

of plant invasions. Conservation Biology 9

(4):761-770.

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sebiferum). . Tallahassee, FL: Florida Department of

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Management.

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by J. Randall and J. Marinelli. Brooklyn, NY:

Brooklyn Botanic Garden.

Kennay, J. 1996. Tamarix ramosissima, T.

chinensis, T. parviflora. In Invasive plants: Weeds of

the global garden, edited by J. Randall and J.

Marinelli. Brooklyn, NY: Brooklyn Botanic Garden.

Koller, G. 1992. Native dictates. American

Nurseryman 175:33-37.

Lang, S., Dunmire, J.R., Edinger, P.,

Williamson, J.F., Walheim, L., and Overbeck Bix,

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by K. N. Brenzel. Menlo Park, CA: Sunset Books.

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eighteenth century: For use and delight. Amherst,

MA: University of Massachusetts Press.

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invading fynbos vegetation. South African Journal of

Plant and Soil 6:39-45.

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and Mulligan, G.A. 1992. The biology of Canadian

weeds. 100. Lythrum salicaria. Canadian Journal

of Plant Science 72:1305-1330.

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trade began. In Origins of American horticulture: A

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Back to Top

ORDINANCE NO. _1220_

AN ORDINANCE OF THE CITY OF MANSFIELD

ESTABLISHING CRITERIA AND REGULATIONS FOR

THE PRESERVATION OF TREES; PROVIDING FOR

DEFINITIONS; PROVIDING FOR PERMIT

REQUIREMENTS; PROVIDING A REVIEW PROCESS;

PROVIDING FOR TREE PROTECTION AND

REPLACEMENT; PROVIDING FOR RESTRICTIONS ON

PRUNING AND PLANTING OF TREES; PROVIDING

ENFORCEMENT PROCEDURES; PROVIDING FOR THE

REPEAL OF ALL ORDINANCES IN CONFLICT;

PROVIDING A SEVERABILITY CLAUSE; PROVIDING

FOR PENALTY FOR VIOLATIONS HEREOF; AND

PROVIDING AN EFFECTIVE DATE.

WHEREAS, the City of Mansfield, Texas, is a home rule City acting under its charter

adopted by the electorate pursuant to Article XI, Section 5 of the Texas Constitution and Chapter

9 of the Local Government Code; and

WHEREAS, trees are a valuable amenity to the urban environment and serve to create

greater human comfort by providing shade, cooling the air and otherwise tempering the effect of

summer heat, thereby reducing the requirements for air conditioning and the subsequent

depletion of scarce energy resources; and

WHEREAS, trees purify the air by filtering pollutants and dust and release oxygen into

the air; and

WHEREAS, trees provide natural habitat for many species of small animals; and

WHEREAS, trees protect land and structures by reducing run-off, binding soil and

minimizing flood damage; and

WHEREAS, trees are known to add dollar value to residential and commercial property

and to increase income levels and tax revenues by attracting new business, industry and residents

through improving a city's image; and

WHEREAS, the City of Mansfield desires to actively participate in the "Tree City

U.S.A." program and the "Keep Mansfield Beautiful", program; and

WHEREAS, the City Council of the City of Mansfield has determined that tree

preservation is necessary to adequately protect the public health, safety and welfare.

NOW, THEREFORE BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF

MANSFIELD, TEXAS:

That this ordinance shall be known as and may be referred to as the “Natural Resources

Management Ordinance.”

Ordinance No. ______

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D:\TREE PRESERVATION\PROPOSED ORDINANCE

NATURAL RESOURCES MANAGEMENT ORDINANCE

A. Purpose and Intent.

The purpose of this ordinance is to promote site planning which furthers the preservation of

mature trees and natural areas, to protect trees during construction; to facilitate site design

and construction which contribute to the long term viability of existing trees; and to control

the removal of trees when necessary. It is the further purpose of this ordinance to achieve the

following broader objectives:

· Prohibit the indiscriminate clearing of property.

· Protect and increase the value of residential and commercial properties within the City.

· Maintain and enhance a positive image for the attraction of new business enterprises to

the City.

· Protect healthy quality trees and promote the natural ecological environmental and

aesthetic qualities of the City.

B. Definitions.

For the purpose of this ordinance, certain words or terms applicable hereto are defined as

hereinafter provided. Words and terms used in this ordinance, but not defined in this

ordinance shall have the meanings ascribed thereto in the Zoning Ordinance or other

ordinances of the City. Words and terms defined in two ordinances shall be read in harmony

unless there exists an irreconcilable conflict in which case the definition contained in this

ordinance shall control. Words used in the present tense shall include the future, words used

in the singular number shall include the plural number and words used in the plural shall

include the singular. The word "shall" is mandatory and the word "may" is permissive. The

word “City” means the City of Mansfield, Texas.

Agricultural Use: The use of land to produce plant or animal products, such as the growing

of crops, raising and pasturing of livestock, or farming. It does not include the processing of

plant or animal products after harvesting or the production of timber or forest products.

Buildable Area: That portion of a building site exclusive of the required yard areas on which

a structure or building improvements may be erected and including the actual structure,

driveway, parking lot, pool and other construction as shown on a site plan.

Building Pad: The actual foundation area of a building and the area within six feet (6’) of the

foundation that is used for construction and grade transition.

Clear-Cutting: The removal of all of the trees or a significant majority of the trees within an

area.

Ordinance No. ______

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D:\TREE PRESERVATION\PROPOSED ORDINANCE

Critical Root Zone (CRZ): The area of undisturbed natural soil around a tree defined by a

concentric circle with a radius equal to the distance from the trunk to the outermost portion of

the dripline. (See Appendix A.)

Cut/Fill: Areas where the natural ground level has been excavated (cut) or fill brought in.

Drip Line: A vertical line run through the outermost portion of the canopy of a tree and

extending to the ground. (See Appendix A.)

Limits Of Construction: A delineation on the graphic exhibit which shows the boundary of

the area within which all construction activity will occur.

Municipal/Public Domain Property: Examples of this would include City Hall, public parks,

County property, Corps of Engineers property, State of Texas R.O.W., library, fire stations,

water tower sites or similar properties.

Protective Fencing: Chain link fence, wire fence, orange vinyl construction fencing, snow

fencing or other similar fencing with a four foot (4') approximate height.

Selective Thinning: The removal of selected trees from within a densely forested area.

Tree: Any self-supporting woody perennial plant which will attain a trunk diameter of two

inches (2") or more when measured at a point four and one-half feet (4.5’) above ground

level and normally an overall height of at least fifteen feet (15’) at maturity, usually with one

(1) main stem or trunk and many branches. It may appear to have several stems or trunks as

in several varieties of oaks.

Tree Board: There is hereby created and established a City Tree Board. This Board shall be

the Planning and Zoning Commission unless otherwise appointed by City Council.

Tree, Marginal: A tree which the City has determined may or may not be worthy of

preservation depending on the individual characteristics of the tree. (See Appendix C.)

Tree, Park: Trees in public parks and all areas owned by the City to which the public has free

access to as a park.

Tree, Protected: A quality tree that has a diameter of six inches (6”) or greater; an understory

tree that has a diameter of two inches (2”) or greater; and a marginal tree that has a diameter

of six inches (6”) or greater that the Landscape Administrator has determined should be

saved due to individual characteristics and/or location of the tree. The diameter of a tree

shall be determined by measuring at four and one-half feet (4.5’) above ground. For a multitrunk

tree, the diameter shall be the total diameter of the largest trunk plus half (½) the

diameter of each additional trunk.

Tree, Quality: A tree which the City has determined typically has significant positive

characteristics worthy of preservation. (See Appendix C.)

Ordinance No. ______

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Tree, Street: Trees on land lying between property lines on either side of all streets, alleys,

avenues, lanes or ways within the City.

Tree Topping: The severe cutting back of limbs to stubs larger than three inches in diameter

within the tree’s crown to such a degree so as to remove the normal canopy and disfigure the

tree.

Tree, Understory: A tree which the City has determined has significant positive

characteristics worthy of preservation and that does not typically attain great size. (See

Appendix C.)

C. General Provisions.

1. Clear-cutting: The clear-cutting of land as defined in this ordinance is prohibited.

2. Selective Thinning: The removal of selected trees from within a densely forested area

when done in a professionally accepted manner shall be allowed as a single permit upon

approval by the Landscape Administrator. Approval will only be granted when the

Landscape Administrator determines that the selective thinning is being done in a manner

that would enhance the environment and likelihood of survival for the remaining trees.

3. Ground Level Cuts: Where protected tree removal is allowed through exemption or by

tree removal permit and the root system is intertwined with protected trees which are

intended to be saved, the tree shall be removed by flush cutting with the natural level of

the surrounding ground. Where stump removal is also desired, stump grinding shall be

allowed, or upon approval of the Landscape Administrator, a trench may be cut between

the two trees sufficient to cut the roots near the tree to be removed, thereby allowing

removal of the remaining stump without destruction of the root system of the saved tree.

D. Tree Removal Permit Required.

No person, directly or indirectly, shall cut down, destroy, remove or move, or effectively

destroy through damaging, any protected tree situated on property regulated by this

ordinance without first obtaining a tree removal permit unless otherwise specified in this

ordinance.

E. New Developments.

All developments which have not submitted final construction plans as of the effective date

of this ordinance shall be subject to the requirements for tree protection and replacement

specified herein.

1. Residential Developments: All area within street right-of-ways, utility or drainage

easements as shown on an approved final plat and area designated as cut/fill on the

master construction plan approved by the Landscape Administrator shall be exempt from

the tree protection and replacement requirements specified herein. The developer may

request the Landscape Administrator to allow trees within potential building pad areas be

Ordinance No. ______

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D:\TREE PRESERVATION\PROPOSED ORDINANCE

included in the exemption described herein. All other area shall be subject to these

requirements.

2. Non-residential Development: All area within street right-of-ways, utility or drainage

easements as shown on an approved final plat, area designated as cut/fill on the master

construction plan approved by the Landscape Administrator, plus fire lanes, parking areas

and building pad as shown on an approved site plan shall be exempt from the tree

protection and replacement requirements specified herein.

3. Permit Requirements: A tree-removal permit shall not be required for removal of a

protected tree within an area noted in Sections E.1 and E.2 above, however a permit must

be obtained prior to the removal of any other protected tree on the property.

4. Landscape Administrator Review:

a. Residential Development: A developer shall be required to furnish a transparency of

the proposed development showing all proposed improvements (e.g. right-of-ways,

easements, lot patterns, cut/fill, etc.) with the submittal of a site plan, development

plan, preliminary plat, or final plat, whichever occurs first. The transparency shall be

on a sheet drawn to the scale of one inch equal to one hundred feet (1”:100’) or on a

computer disk in the format of a commonly used Computer-Aided Design (CAD)

program. The Landscape Administrator is authorized to require a tree survey meeting

the requirements of Appendix D herein when determined to be needed to fully

evaluate the impact on trees.

b. Non-Residential Development: A developer shall be required to furnish a

transparency of the proposed development showing all proposed improvements (e.g.

right-of-ways, easements, lot patterns, cut/fill, fire lanes, parking areas and building

pads, etc.) with the submittal of a site plan, development plan, construction plan, plot

plan or building permit application, whichever occurs first. The transparency shall be

on a sheet drawn to a scale as required by the Landscape Administrator and in a

format depicted in Section E.4.a above. The Landscape Administrator is authorized

to require a tree survey meeting the requirements of Appendix D herein when

determined to be needed to fully evaluate the impact on trees.

c. It is highly recommended that the developer consult with the Landscape

Administrator and submit the required transparency or survey for review as early as

possible so as to minimize changes in preliminary or final plats and to determine that

there is adequate area for the proposed improvements after tree protection and

replacement have been taken into consideration.

d. The Landscape Administrator will evaluate the required transparency, survey or plan

to determine that the developer has made a best good-faith effort at saving as many

protected trees as possible. The Administrator will forward review comments to the

Planning and Zoning Commission for consideration regarding denial or approval of

the development. If the review involves a document that normally does not require

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the approval of the Planning & Zoning Commission, the Administrator will follow

the procedures in Section I herein.

5. Parking Area: When a non-residential development consists of extra parking spaces

beyond 110% of the minimum parking spaces required by the Zoning Ordinance, the

developer shall be required to replace a percentage of the trees removed or make a

payment into the Tree Restoration Fund. The replacement trees shall be calculated by

multiplying the total diameter of trees removed in all parking spaces by the percentage of

said extra parking spaces to the total number of parking spaces (i.e. total diameter of trees

removed x extra parking spaces ÷ total parking spaces). The replacement trees shall be

provided in accordance with Section J herein.

F. Private Property.

1. Homestead: The owner of property which is used for an individual residence or

homestead shall be exempt from the tree protection and replacement requirements

specified herein.

2. Property Owned by Home Builder: All area within the building pad, driveway, sidewalks,

patios, septic tank and lateral lines, parking area, pool and associated deck area as shown

on a plot plan approved by the Landscape Administrator shall be exempt from the tree

protection and replacement requirements specified herein. All other area of the lot shall

be subject to these requirements.

a. Permit Requirements: A tree-removal permit shall not be required for removal of a

protected tree within an area noted above, however a permit must be obtained prior to

the removal of any other protected tree on the property.

b. Landscape Administrator Review: A transparency showing all proposed

improvements shall be required with the submittal of building permit application.

The transparency shall be on a sheet drawn to a scale as required by the Landscape

Administrator or on a computer disk in the format of a commonly used Computer-

Aided Design (CAD) program. The Landscape Administrator is authorized to require

a tree survey meeting the requirements of Appendix D herein when determined to be

needed to fully evaluate the impact on trees.

3. Agricultural Property: The owner of property being actively used for agricultural

purposes shall be permitted to remove up to seven (7) protected trees per calendar year

without obtaining a permit. Protected trees removed in excess of seven will require

permits. It is not the intent of this ordinance to prohibit the clearing of land for

legitimate, agricultural use. The property owner shall request the Landscape

Administrator to make an on-site inspection of the property to be cleared and provide the

Landscape Administrator the purpose and reason for the clearing. If the Landscape

Administrator determines the clearing of land to be for a legitimate, agricultural reason,

he will issue a tree removal permit.

G. Municipal/Public Domain Property, Right-of-ways and Easements.

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All construction and maintenance activities within municipal/public domain property, rightof-

ways or easements by the City, franchise utility companies or other entities shall be

subject to the requirements for tree protection and replacement specified herein.

1. A tree removal permit shall not be required for removal of a protected tree. However no

construction or maintenance activity that may cause the removal of a protected tree shall

begin until construction plans showing protected trees to be removed and the location of

replacement trees have been approved by the Landscape Administrator. Pruning

activities by a utility shall be governed by the provisions of Section M.

2. Tree Board Responsibilities: It shall be the responsibility of the Tree Board to study,

investigate, counsel and develop and/or update periodically, and administer a written plan

for the care, preservation, pruning, planting, replanting, removal or disposition of trees in

parks, along streets and in other public areas. Such plan shall be presented to the

Council, and when adopted, shall represent the comprehensive tree plan for the City.

3. Acceptable Trees: The Landscape Administrator shall maintain a list of trees acceptable

for planting along streets, within parks or other public areas. Trees other than those listed

as acceptable may only be planted upon approval of the Landscape Administrator.

4. Street Tree Spacing: The spacing of street trees shall be in accordance with

recommendations of the Landscape Administrator. Closer spacings or group plantings

may be approved by the Landscape Administrator in unique situations and when

recommended by a registered Landscape Architect.

5. Public Tree Care: The City shall have the right to plant, prune, and maintain street trees

and park trees within the lines of all streets, alleys, avenues, lanes, squares, and public

grounds, as may be necessary to insure public safety or to preserve or enhance the

symmetry and beauty of such public properties. The City may remove or cause or order

to be removed any tree or part thereof, which is in an unsafe condition, or which by

reason of its nature is injurious to sewers, electric power lines, gas lines, water lines or

other public improvements, or which is affected with any injurious fungus, insect or other

pest.

H. Exceptions

A tree removal permit and tree protection and replacement requirements shall not be required

under any of the following circumstances. The burden of proof as a qualified exemption is

upon the remover of a tree. It is highly recommended that qualification as an exemption be

determined with the Landscape Administrator prior to removal of any tree.

1. All construction activities for which final construction plans and building permit

applications have been submitted prior to the effective date of this ordinance shall be

exempt.

2. Diseased Trees: The tree is diseased, damaged beyond the point of recovery, or in danger

of falling as determined by the Landscape Administrator prior to the removal of the tree.

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The removal of a diseased tree by the City or an individual is required to reduce the

chance of spreading the disease to adjacent healthy trees.

3. Public Safety: The tree endangers the public health, welfare or safety and immediate

removal is required.

4. Utility Service Interruption: The tree has disrupted a public utility service due to a

tornado, storm, flood or other act of God. Removal shall be limited to the portion of the

tree reasonably necessary to reestablish and maintain reliable utility service.

5. Landscape Nursery: All licensed plant or tree nurseries shall be exempt from the

requirements of this ordinance as they pertain to those trees planted and growing on the

premises of said licensee that are so planted and growing for the sale or intended sale to

the general public in the ordinary course of said licensee's business.

I. Permit Review and Approval Process.

1. Authority for Review: The Landscape Administrator shall be responsible for the review

and approval of all requests for tree removal permits submitted in accordance with the

requirements specified herein.

a. Deferrals: The Landscape Administrator may defer the approval of a tree removal

permit to the Tree Board for any reason. All decisions made by the Tree Board shall

be final.

b. Appeals: Any decision made by the Landscape Administrator may be appealed to the

Tree Board. All decisions made by the Tree Board shall be final.

2. Submittal Requirements: The Landscape Administrator shall establish administrative

procedures necessary to facilitate the implementation and enforcement of this ordinance.

a. Tree Removal Permit: A request for a tree removal permit must be submitted and

approved prior to the removal of any protected tree in the City unless the tree is

exempt under a provision of this ordinance.

b. Fees: All tree removal permits shall be accompanied by a payment made to the City

in the amount specified by City Council.

c. Required Documents: Either a transparency or tree survey shall be required as

determined by the Landscape Administrator and must include the items referenced in

this ordinance and its appendices.

d. Permit Expiration: Permits for tree removal issued in connection with a building

permit or site plan shall be valid for the period of that building permit’s or site plan’s

validity. Permit(s) for tree removal not issued in connection with a building permit or

a site plan shall become void one hundred eighty (180) days after the issue date on the

permit.

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3. Action on Permit Application: The Landscape Administrator or the Tree Board shall

grant a tree removal permit based on the following criteria:

a. Whether or not a reasonable accommodation or alternative solution can be made to

accomplish the desired activity without the removal of the tree;

b. The cost of preserving the tree;

c. Whether the tree is worthy of preservation. Trees listed as marginal trees in

Appendix C usually are not considered worthy of preservation depending on the

individual characteristics of the tree;

d. The effect of the removal on erosion, soil moisture, retention, flow of surface waters,

and drainage systems;

e. The need for buffering of residential areas from the noise, glare, and visual effects of

nonresidential uses;

f. Whether the tree interferes with a utility service;

g. Whether the proposed tree replacement pursuant to the Tree Replacement

Requirements hereof adequately mitigates the removal of the tree;

h. Whether the removal affects the public health, safety or welfare.

J. Tree Replacement Requirements.

1. Tree Replacement: In the event that it is necessary to remove a protected tree as specified

in Section E through G herein, the party (other than franchise utility companies)

removing the tree shall be required to replace the protected trees being removed with

quality trees as defined herein. A sufficient number of trees shall be planted to equal or

exceed the diameter (measured at 4.5’ above ground level) of each tree removed. This

mitigative measure is not meant to supplant good site planning. Tree replacement will be

considered only after all design alternatives which could save more existing trees have

been evaluated and reasonably rejected. Said replacement trees shall be a minimum of 3”

diameter (measured at l’ above ground) and seven feet (7’) in height when planted.

2. Replacement Procedures:At the time of review, the agent responsible for replacement, the

time of replacement and the location of the new trees will be determined by the

Landscape Administrator. The replacement trees shall be located on the subject site

whenever possible. However if this is not feasible, the Landscape Administrator has the

authority to allow the planting to take place on another property, including public

property. Franchise utility companies shall be exempt from this requirement. If the

Landscape Administrator approves the planting of replacement trees more than 30 days

after the removal of protected trees, the applicant shall provide the Landscape

Administrator with an affidavit that all replacement trees will be planted within six

months. Any replacement tree required by this ordinance must be covered by a one-year

warranty that is acceptable to the Landscape Administrator.

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3. Tree Reforestation Fund: In a densely forested area, the applicant, upon approval of the

Landscape Administrator, may make a payment into the Tree Reforestation Fund in lieu

of planting the replacement tree on the subject site. The funds shall be used only for

purchasing and planting trees on public property or acquiring wooded property which

shall remain in a naturalistic state in perpetuity. The amount of the payment required for

each replacement tree shall be calculated based on a schedule published annually by the

Landscape Administrator which sets forth the average cost of a quality tree added to the

average cost of planting a tree.

K. Additional Duties and Authorities of the Tree Board

The Tree Board shall have the responsibility to review and grant a tree removal permit for the

following land use:

1. Any public or recreational use that is deemed acceptable to the Tree Board.

2. Any private use that is deemed acceptable to the Tree Board that usually requires large

areas of open space.

3. In granting the tree removal permit, the Tree Board is authorized to impose whatever

conditions of approval that is deemed necessary by the Tree Board.

L. Tree Protection.

A major purpose of this ordinance is to protect all protected trees which are not required to

be removed to allow approved construction to occur. The following procedures are required:

1. Construction Plan Requirements: All construction plans shall include the requirements

noted in Appendix E.

2. Prohibited Activities: The following activities shall be prohibited within the limits of the

critical root zone of any protected tree subject to the requirements of this ordinance.

a. Material Storage: No materials intended for use in construction or waste materials

accumulated due to excavation or demolition shall be placed within the limits of the

critical root zone of any protected tree. However, this restriction shall not apply to

material storage in areas exempt from the tree protection and replacement

requirements (e.g. building pad, driveway, patios, parking lot, etc.)

b. Equipment Cleaning/Liquid Disposal: No equipment shall be cleaned or other liquids

deposited or allowed to flow overland within the limits of the critical root zone of a

protected tree. This includes, without limitation, paint, oil, solvents, asphalt,

concrete, mortar or similar materials.

c. Tree Attachments: No signs, wires or other attachments, other than those of a

protective nature shall be attached to any protected tree.

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d. Vehicular Traffic: No vehicular and/or construction equipment traffic or parking shall

take place within the limits of the critical root zone of any protected tree other than on

an existing street pavement. This restriction does not apply to single incident access

within the critical root zone for purposes of clearing underbrush, establishing the

building pad and associated lot grading, vehicular traffic necessary for routine utility

maintenance or emergency restoration of utility service or routine mowing operations.

e. Grade Changes: No grade changes shall be allowed within the limits of the critical

root zone of any protected tree unless adequate construction methods are approved by

the Landscape Administrator or if grading is as directed by the city’s drainage

inspector.

f. Impervious Paving: No paving with asphalt, concrete or other impervious materials in

a manner which may reasonably be expected to kill a tree shall be placed within the

limits of the critical root zone of a protected tree except as otherwise allowed in this

ordinance.

3. Preserved Tree: A protected tree shall be considered to be preserved only if a minimum

of 75% of the critical root zone is maintained at undisturbed natural grade and no more

than 25% of the canopy is removed due to building encroachment.

4. Prior to Construction: The following procedures shall be followed on all types of

construction projects (i.e. residential subdivisions, commercial, multi-family, industrial

developments, residential builders and municipal/public).

a. Tree Flagging or Marking: Trees that are approved by the Landscape Administrator

for removal shall be flagged with bright fluorescent orange vinyl tape wrapped

around the main trunk or marked with bright fluorescent orange paint at a height of 4'

or more such that it is very visible to workers operating construction equipment. This

shall not include the flagging or marking of all protected trees adjacent to right-ofway

within approved residential subdivisions during the construction of the roadway.

Trees that are not flagged or marked shall be saved and protected by fencing in

accordance with the requirements hereinafter.

b. Protective Fencing: In those situations where a protected tree is so close to the

construction area that construction equipment might infringe on the root system or is

within twenty feet (20’) of the construction area, a protective fencing shall be

required between the outer limits of the critical root zone of the tree and the

construction activity area. Four feet (4’) high protective fencing shall be supported at

a maximum of 10’ intervals by approved methods. All protective fencing shall be in

place prior to commencement of any site work and remain in place until all exterior

work has been completed.

c. Bark Protection: In situations where a protected tree remains in the immediate area of

intended construction, the tree shall be protected by enclosing the entire

circumference of the tree with 2" x 4" lumber encircled with wire or other means that

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do not damage the tree. The intent here is to protect the bark of the tree against

incidental contact by construction equipment.

5. Permanent Construction Methods

a. Boring: Where it is not possible to trench around the critical root zone of a protected

tree, boring of utilities under the protected tree shall be required. The length of the

bore shall at least be the width of the critical root zone and the depth of the bore shall

at least be twenty-four inches (24”).

b. Grade Change: In situations where the grade change within the critical root zone of a

protected tree exceeds the limits noted in Section L.2.e herein, the procedures noted

in the City standard detail sheet shall be required.

c. Trenching: All trenching shall be designed to avoid trenching across the critical root

zone of any protected tree. Although this section is not intended to prohibit the

placement of underground services such as electric, phone, gas, etc., the placement of

these utilities is encouraged to be located outside of the critical root zone of protected

trees. Irrigation system trenching shall be placed outside of the critical root zone with

only the minimum required single head supply line allowed within that area placed

radially to the tree trunk.

d. Root Pruning: All roots 2”or larger in diameter which are exposed as a result of

trenching or other excavation shall be cut off square with a sharp medium tooth saw

and covered with pruning compound within 2 hours of initial exposure.

M. Tree Pruning Restrictions.

1. General: No protected tree should be pruned in a manner which significantly disfigures

the tree without proper cause or in a manner which would reasonably lead to the death of

the tree.

2. Permit Requirements: All franchise utility companies shall be required to maintain at the

City a set of pruning specifications (updated annually) to be followed by all pruning

contractors working for the company within the City. Prior to beginning any pruning not

requested by the owner of the tree, the contractor for a non-franchise entity shall submit

to the City an application for a pruning permit for approval. Utility companies may prune

trees as necessary to maintain safe and reliable service or to re-establish disrupted electric

service without obtaining a permit.

3. Allowed Pruning: The Landscape Administrator may approve pruning of a protected tree

in cases where protected trees must be strategically pruned to allow construction or

demolition of a structure. When allowed, all pruning shall be in accordance with Section

L.3 above, approved Arboricultural techniques and the recommendations of Appendix F.

This section is not intended to require a tree permit for reasonable pruning performed or

contracted to be performed by the owner of the tree when unrelated to construction

activity.

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4. Required Pruning: The owners of all trees adjacent to public right-of-way shall be

required to maintain a minimum clearance of ten feet (10’) above the traveled pavement

or curb of a public street. Said owners shall also remove all dead, diseased or dangerous

trees, or broken or decayed limbs which constitute a menace to the safety of the public.

The City shall also have the right to prune trees overhanging within public right-of-way

which interfere with the proper spread of light along the street from a street light or

interfere with visibility of any traffic control device or sign or as necessary to preserve

the public safety.

5. Tree Topping: It shall be unlawful as a normal practice for any person, firm, or city

department to top any street tree, park tree or other tree on public property. Trees

severely damaged by storms or other causes, or certain trees under utility wires or other

obstructions where other pruning practices are impractical may be exempted from this

ordinance at the determination of the Landscape Administrator.

N. Tree Planting Restrictions.

1. Overhead Lines: Any required replacement trees shall not be planted within an area such

that the mature canopy of the tree will be within ten feet (10’) of overhead utility lines.

2. Proximity to Utilities: Any required replacement trees or street trees shall not be planted

within five feet (5’) of electrical facilities (underground or surface), public utility lines,

including water lines, sewer lines, transmission lines or other utilities. No trees shall be

planted within ten feet (10’) of a fire hydrant. Shrubs will be permitted outside of the

minimum clearance of surface electrical facilities established by the franchise electrical

company.

3. Street Corners: No street tree shall be planted closer than twenty-five feet (25’) of any

street corner, measured from the point of nearest intersecting curbs or curblines.

O. Enforcement.

1. Building Permit: No building permit shall be issued unless the applicant signs an

application or permit request which states that all construction activities shall meet the

requirements of this ordinance. The Building Official shall make available to the

applicant a copy of this ordinance or a condensed summary of the relevant aspects

pertaining to the type of permit requested.

2. Acceptance of Improvements: No acceptance of public improvements shall be authorized

until all fines for violations of this ordinance have been paid to the City or otherwise

disposed of through the Municipal Court. No acceptance of public improvements shall

be authorized until all replacement trees have been planted or appropriate payments have

been made to the Tree Reforestation Fund.

3. Certificate Of Occupancy: No Certificate of Occupancy shall be issued until all fines for

violations of this ordinance have been paid to the City or otherwise disposed of through

the Municipal Court. No Certificate of Occupancy shall be issued until all replacement

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trees have been planted or appropriate payments have been made to the Tree

Reforestation Fund.

4. Notwithstanding the above provisions, public improvements may be accepted and

Certificate of Occupancy may be issued before all trees have been replaced if a fiscal

security is posted in an amount equal to the prevailing rate for installed trees with a one

(1) year guarantee, plus fifteen percent (15%) to cover administrative costs.

P. Conflicting Ordinances

That all ordinances of the City in conflict with the provisions of this ordinance be, and the

same are hereby, repealed and all other ordinances of the City not in conflict with the

provisions of this ordinance shall remain in full force and effect.

Q. Severability

Should any paragraph, sentence, subdivision, clause, phrase or section of this ordinance be

adjudged or held to be unconstitutional, illegal or invalid, the same shall not affect the

validity of this ordinance as a whole or any part or provision thereof, other than the part so

declared to be invalid, illegal or unconstitutional, and shall not affect the validity of the

Comprehensive Zoning Ordinance as a whole.

R. Penalty

1. Any person, firm, corporation, agent, or employee thereof who violates the provisions of

Section D through H of this ordinance shall be guilty of a misdemeanor and upon

conviction hereof shall be fined not to exceed One Hundred Dollars ($100.00) per

diameter inch of the tree(s) removed or damaged.

2. Any person, firm, corporation, agent or employee thereof who violates any other

provisions of this ordinance shall be guilty of a misdemeanor and upon conviction hereof

shall be fined not to exceed Five Hundred Dollars ($500.00) for each incident. The

unlawful injury, destruction or removal of each protected tree shall be considered a

separate incident and each incident subjects the violator to the maximum penalty set forth

herein per tree.

3. Removal of Public Trees: It shall be deemed a violation of this ordinance for any person

or firm to engage in the business or occupation of pruning, treating, or removing street or

park trees within the City without first procuring approval from the Landscape

Administrator.

S. Appendices

It is anticipated that the following appendices will be changed periodically by the Landscape

Administrator in response to changes in the administration of this ordinance.

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T. Effective Date

This ordinance shall take effect immediately from and after its passage on third and final

reading and the publication of the caption, as the law and charter in such cases provide.

First reading approved on the 22nd day of June, 1998.

Second reading approved on the 13th day of July, 1998.

DULY PASSED on the third and final reading by the City Council of the City of Mansfield,

Texas, this 27th day of July, 1998.

David Harry, Mayor

ATTEST:

Judy Howard, City Secretary

APPROVED AS TO FORM AND LEGALITY

Allen Taylor, City Attorney

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APPENDIX A

TREE EXHIBIT

Critical Root Zone (CRZ): The area of undisturbed natural soil around a tree defined by a

concentric circle with a radius equal to the distance from the trunk to the outermost portion of

the dripline.

Drip Line: A vertical line run through the outermost portion of the canopy of a tree and

extending to the ground.

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APPENDIX B

TREE DIAMETER MEASUREMENT

ON A SLOPE IRREGULAR SWELLING

(requires discretion by

Landscape Administrator)

MULTI-TRUNK TREE LEANING TREE

Source: COA

Diameter Measurement: The diameter of a tree shall be measured as shown above. The

diameter of a multi-trunk tree shall be the total diameter of the largest trunk plus half the

diameter of each additional trunk.

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APPENDIX C

Quality Trees

Common Name Botanical Name Identification Notes

Pecan Carya illinoensis Pecan fruit, compound leaves

Cedar Elm Ulmus crassifolia Deciduous, 1"-2" dark green leaves

Shumard Red Oak Quercus shumardii Deep pointed lobes in leaves

Texas Red Oak Quercus texana Vertical multi-trunk shape

Live Oak Quercus virginiana 1 ½" dark green pointed leaves

Bur Oak Quercus macrocarpa Large acorn, leaf border at end

Post Oak Quercus stellata Deep lobes, rounded tip on leaf

Black Jack Oak Quercus marilandica Leathery 3"-7" leaf, no lobes

Lacebark Elm Ulmus parvifolia Small dark serrated green leaves

Chinese Pistache Pistacia chinensis 3" sickle leaflets, fall color

Sweetgum Liquidambar styraciflua Star shaped leaf

Austrian Pine Pinus nigra Two needles

Chinquapin Oak Quercus muhlenbergii Oblong 4"-6" serrated leaf

Southern Magnolia Magnolia grandiflora Large evergreen Leaf, white flower

Bald Cypress Taxodium distichum Feather-like foliage, fall color

Caddo Maple Acer barbatum 'Caddo' Five-lobed leaf

Texas Hickory Carya texana Five leaflets, 1"-2" nut

Western Soapberry Sapindus drummondii 18" compound leaf, ½" clear fruit

Red Cedar Juniperus virginiana Native, pyramidal shape

Marginal Trees

Common Name Botanical Name Identification Notes

Cottonwood Populus deltoides Deep fissures in bark, heart shape leaf

Mesquite Prosopis glandulosa Lacy open foliage, 10" bean fruit

American Elm Ulmus americana 'V' shaped main branching

Slash Pine Pinus elliotti Tall cylindrical shape

Honeylocust Gleditsia triacanthos Lacy foliage, thornless variety only

Japanese Black Pine Pinus thunbergii Twisted growth, dark green needles

Deodar Cedar Cedrus deodara Large pyramidal evergreen

Understory Trees

Common Name Botanical Name Identification Notes

Redbud Cercis canadensis Purple/white flower in spring

Mexican Plum Prunis mexicana White flower, exfoliating bark,thorns

Possumhaw Holly Ilex decidua Showy orange/red fruit, deciduous

Golden Raintree Koelrutaria paniculata Yellow flower, panicled fruit

Yaupon Holly Ilex vomitoria Evergreen, light bark, red fruit

Cherry Laurel Prunus caroliniana Glossy evergreen foliage, shrubby

River Birch Betula nigra White flaky bark

Eves Necklace Sophora affinis Dull green tear-dropped shape leaf

Persimmon Diospyros virgininana Thin, smooth, pale grey bark

Rusty Blackhaw Viburnum rufidulum Glossy, dark green leaved, white flowers

Wax Myrtle Myrica cerifera Light olive-green leaves, pale blue berries

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APPENDIX D

LIST OF ITEMS REQUIRED ON TREE SURVEY

1. Appropriate Title (i.e. Tree Removal Exhibit, or Tree Survey)

2. Title block which includes street address, lot and block, subdivision name, city and date of

preparation.

3. North arrow, graphic and written scale in close proximity

4. Scale at a size no larger than 1” = 100’ for residential development; scale to be determined by the

Landscape Administrator for non-residential and home building activities.

5. Name, address and phone of owner and person preparing the document

6. Location of all right-of-way lines and public easements

7. Location of all buildings, structures, pools, parking and other improvements which are existing or

intended on the lot

8. Areas of cut/fill with amount of each shown and flow lines shown

9. Existing and proposed spot elevations, grades and major contours, along with existing landscaping,

streams, ponds and major natural features.

10. Areas of no disturbance labeled as “No Disturbance Area”. This area must be clearly marked on the

plan and surrounded with protective fencing on the ground. A single incidence removal of

underbrush and vines is allowed. 1

11. All protected trees shown individually on the plan. 2 Canopy Trees 6" or greater in size and

Understory Trees 2" or greater in size. Trees in close proximity that all have a caliper of less than

four inches (4") may be designated as a group of trees with quantity of quality, marginal and

understory trees shown. (see Appendix C)

12. The location of protected trees must be tied by horizontal control (i.e. dimensions from lot lines, or

placed through coordinates determined via survey.)

13. All protected trees shown with diameter (4.5' from the ground), common name and condition.

14. Any proposed replacement trees shown with caliper size, common name of tree and mature size.

15. Graphic representations distinguishing protected trees that will be saved versus those that will be

removed.

16. Phasing of tree survey along with phasing of the development is permitted.

Notes:

1 The Landscape Administrator shall have the authority to designate areas as “no disturbance” areas where a survey

would not be required due to no intended construction.

2 An area may be designated as a “No Disturbance Zone” on the plan when approved by the Landscape

Administrator and trees within that zone are not required to be individually identified on the plan.

3 The Landscape Administrator shall have the authority to exempt any of the above items that he deems to be not

applicable.

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APPENDIX E

CONSTRUCTION PLAN REQUIREMENTS

The following shall be required as a part of all construction plans submitted to the City when tree removal

or tree protection is required during any phase of site work or construction.

1. A Tree Preservation Detail Sheet shall include the following at a minimum.

a. The requirements of Section L.2 to L.4 shall be noted.

b. A graphics legend to be used throughout the plans for the purposes of showing the following:

Trees to be flagged, protective fencing, trees requiring bark protection, boring, areas of cut and

fill impacting protected trees.

c. Graphic tree exhibit showing the features of a tree to include the critical root zone, trunk, canopy,

drip line and method of diameter measurement (per Appendices A & B).

d. Graphic exhibits showing methods of protection to include snow fences, boarded skirts, etc.

e. Graphic exhibits showing construction methods to include grade changes, boring, trenching etc.

f. Graphic exhibit showing appropriate pruning practices (per Appendix F).

2. All practices which will be employed in meeting the requirements of this ordinance shall be shown

graphically on all applicable sheets within the construction plans.

3. Documents as required in Appendix D herein.

Ordinance No. ______

Page 21

D:\TREE PRESERVATION\PROPOSED ORDINANCE

APPENDIX F

TREE PRUNING RECOMMENDATIONS

When removing a branch, always cut outside the

branch bark ridge and collar. Do not make a flush

cut.

Branches that do not have a distinct collar

should be cut at a right angle to the branch

outside the branch bark ridge.

Trees may have codominant stems, as shown on the

left. If a codominant stem must be removed, cut at

an angle outside of the bark ridge as shown in the

insert at right. Avoid leaving any stub.

When removing heavy limbs, first make an

undercut several inches outside of the collar.

Then remove limb by a second cut an inch or so

outside of the first cut. Remove stub with a

third cut just outside of the collar. (Feucht,

1985)

Go to Top

Managing Space to Manage Growth

 

 

Daniel R. Mandelker*

                                                                 

 

Oregonians don’t like sprawl, but they don’t like high density either.

            —John A. Kitzhaber, Governor of Oregon

 

 

As growth management programs come of age, experience can tell us how they work and what can make them more effec­tive.  Strategies that manage space to manage growth are important elements in these programs.  Space manage­ment directs develop­ment to one part of an urban area, but limits it else­where, to attain the policies that growth management adopts.

This article examines two long­standing growth management programs that rely on space management: the tiered growth program in San Diego, and the urban growth bound­ary program in Oregon, as carried out in Port­land.  The article first reviews the goals that growth manage­ment seeks to achieve.  It then dis­cusses the San Diego and Port­land programs, focusing on the strategies adopted in these programs and the extent to which they were successful.  Finally, this article concludes with recommen­dations for improving space management strategies.

 

I.                    Urban Sprawl and the Growth Management Movement

 

Growth management began in the 1960s to provide new tech­niques for managing rapid and uncon­trolled growth through urban sprawl.   Though there is no consensus on a definition of sprawl, commentators usually characterize it as low-density develop­ment that expands as leapfrog noncontig­uous development from the core of metropolitan areas.[1]  Regulations for the Florida state land use planning program define urban sprawl as premature and poorly planned conversion of rural land, and development that does not relate to adjacent land uses and does not make maximum use of existing public facilities.[2]

Critics of sprawl would point to its many problems.[3]  These include higher capital and operating costs for private and public facili­ties, higher trans­portation and travel costs, and the excessive consump­tion of agricultural and sensitive lands.  They also include the deterioration in the quality of life, and social impacts, such as suburban exclu­sion and a mismatch of jobs and housing.[4]

The criticism that urban sprawl increases capital facili­ty and service costs gained major support in an early influential study.  It showed the cost of ser­vicing scat­tered and low-density develop­ment is much higher than the cost of servic­ing compact develop­ment at higher densi­ties.[5]  Critics contested these find­ings,[6] but most studies conclude that lower densities and urban sprawl do result in higher capital facility costs.[7]  Studies have also found mod­est, but cumula­tive­ly signifi­cant, reductions in operating costs for compact rather than sprawl develop­ment.[8]  These find­ings are impor­tant to the legal basis for growth manage­ment programs that remedy this prob­lem.  Courts have held, and are likely to continue to hold, that land use programs requiring the orderly provision of servic­es and facili­ties at optimal cost is a legiti­mate govern­mental objective in growth management.[9] 

A related timing problem is that rapid development may overwhelm a community so that it cannot provide facilities and services when new development needs them.  Local governments can han­dle this problem by provid­ing necessary facilities in advance before growth occurs, but few have the re­sourc­es to do so.[10]  Growth man­age­ment can time development so that local govern­ments can budget and plan for needed services and facilities.

Policy makers who became concerned with urban sprawl soon realized that zoning cannot handle the sprawl problem.  Original­ly a static system that designated where develop­ment could occur, zoning gradu­ally became a more flexi­ble process in which local governments could review develop­ment proposals as they were presented for review.  Though this process could have controlled the rate, timing, and charac­ter of growth, it did not do so because compre­hensive plans, and thus land development regulations, did not consider these issues.[11]

Because the problems that drive growth management programs vary, it is difficult to define what growth manage­ment does.  The convention­al understanding is that growth manage­ment influ­ences the rate, amount, type, loca­tion and quality of growth.  One topology lists four types of controls: adequate public facilities programs that prohibit development unless adequate public facili­ties are available, phased growth programs that determine when to allow develop­ment, urban growth boundary programs that set limits on urban growth, and rate-of-growth programs that estab­lish a defined growth rate.[12]

These strategies reflect the various origins of the growth management movement.  Some focus on the provision of public facilities and try to time the provision of these facilities with new development.  Other strategies manage space, and attempt to regulate the rate of growth or determine where development should lo­cate. Programs with spatial dimensions, such as urban growth boundary programs,[13] control the shape and form of development.  Space management is new to American land use planning, though it has long been a key element of land use planning in other coun­tries.  An example is the British Green Belt pro­gram, which limits the growth of cities to pre­serve agri­cultural land and prevent urban sprawl.[14]

Space management programs are especially critical because they dramatically affect the spatial form of development in ways not typical in American tradition.  They are good faith efforts to modify development patterns to provide a more desir­able pattern for urban growth.  Urban growth boundaries, for example, establish a boundary line beyond which new develop­ment cannot occur.  These programs have major effects on the land market because they prevent development where it otherwise might occur and because they direct development to areas where it might not otherwise occur.  Space management programs also have an implicit preference for higher-density, compact urban develop­ment in areas where develop­ment can occur.[15]  This high-density preference is a corollary to the criticism of low-density sprawl, which is considered wasteful and difficult to service.

Two major growth management programs in western cities have made use of space management for over a quarter of a century.  They deserve study as examples of how these pro­grams work.  One is the tiered system of growth management in San Diego, Califor­nia.  The other is the urban growth boundary in place in Port­land, Oregon, which the state planning pro­gram requires.

 

II.                 Tiered Growth in San Diego[16]

 

San Diego, though it has cycled through boom and bust periods, is one of the fastest-growing cities in the coun­try.  It is also one of the most desirable.  Growth management became a major issue in the 1970s, when growth accelerated.  The city was large enough, and had enough undeveloped area, so that a growth manage­ment strategy made sense within the city limits.  When growth became a major problem in the 1970s, the city called in a national consultant who had prepared and successfully defended a phased growth program in New York State.[17]  This consultant proposed a tiered growth management pro­gram for San Diego.[18]  The intro­duc­to­ry chap­ter of his report details the purpose and strategy of the program:

 

The growth strategy supports neither extreme of unre­strained expansion nor the complete cessation of growth.  Rather, it conceives that urban growth will occur in logi­cally defined increments phased with and/or adjusted to the City’s capacity for accom­modating such increments.[19]

 

This statement shows that the principal objective of the program was the provision of facilities needed to serve new devel­opment.[20]  Its principal concerns were the staging and timing of growth, the timely provision of public facili­ties within areas where growth could occur, and a requirement that new development should pay the capital costs it re­quires.[21] 

The city also faced several space manage­ment prob­lems.  Downtown and inner city areas were not attracting enough new development, while excessive develop­ment threatened the northern tier.  This type of growth pattern would ultimately have produced low-density sprawl in outlying areas, while the inner city de­clined.  The city also has important wetlands, canyons and other natural resource areas that resi­dents value, which new develop­ment threatened.

As adopted, the program has three growth tiers: an urban­ized tier, a planned urban­iz­ing tier, and an urban reserve tier.[22]  The consultant’s proposal encouraged growth in the urbanized tier, staged growth in the planned urbanizing tier,[23] and de­ferred growth for fifteen to twenty years in the urban reserve.  It also includ­ed an environ­men­tal tier intend­ed to protect the area’s canyons, steep slopes and other natural resources, but the city did not adopt it.[24]  The growth manage­ment program only applies to resi­dential development, because it assumed nonres­iden­tial develop­ment will carry its fair share of needed im­prove­ment costs and does not affect the need for schools, parks and librar­ies.[25]

The consultant’s proposal included different policies and objectives for each tier, most of them regulato­ry, though it proposed other measures, such as redevel­opment, where it was necessary in the urbanized tier.  There was no strategy for allo­cat­ing growth to designated areas within the tiers where the program allowed growth.  Neither was enough attention paid to the need for capital improvements in the urbanized tier, though there was a brief discussion of a capital improvements pro­gram.[26]  In the planned urbanizing tier the city adopted a special benefits assessment, which the courts eventually up­held,[27] that carried out the program’s proposal to shift the cost of new facili­ties to developers.  In the urban reserve the princi­pal control was large lot zoning at a minimum of ten acres for each dwelling unit.  This type of zoning protects land from urban growth because the density it allows is too low to allow development at an inten­sive scale.

The San Diego plan cre­atively used several stan­dard land use measures to manage the rate and direc­tion of growth, though the options then available limited its choice.  Today, for example, there is greater support for programs that protect threatened environ­men­tal areas.[28]  An innovative devel­op­ment exac­tion shift­ed the cost of new public facilities to develop­e­rs in the planned urbaniz­ing area.  Problems that arose later reflect, to some extent, the political climate in which the program began.  Its growth restrictions were partly a re­sponse to an initiative propos­al that would have limited growth in the city.  Yet the decision to make large areas unavailable for develop­ment was both novel and dangerous, as the develop­ment industry had never faced the obstacle that large areas of a municipality were off limits.  To reduce opposition to this policy, the city made conces­sions.  It removed a substan­tial area from the future urbaniz­ing to the planned urbanizing tier and dropped the open space tier from the pro­gram.[29]  Neither did the city adopt leg­is­lation protecting natural resource and sensi­tive areas until 1990.[30]

At first, the program succeeded.  Develop­ment in­creased dramati­cally in the urbanized areas, and growth in the planned urbaniz­ing area de­clined.  A major factor in this shift in development preferenc­es was the absence of a development exaction in the urbanized areas.[31]

Problems arose with the facilities benefits assessment in the planned urbanizing area.  Judicial approval of the assessment took seven years,[32] and the collec­tion of fees then lagged infra­structure needs.[33]  Prob­lems also occurred in the urban­ized area.  An obsolete zoning code allowed eight-plex apart­ment build­ings in single-family neighbor­hoods, front-yard park­ing, and other undesirable design practices that pro­voked neigh­borhood objec­tions.[34]  Alarmed residents put pressure on the city to adopt legislation to protect inner area neigh­bor­hoods from multifamily develop­ment.[35]

Problems also arose with the adequacy of public facilities in the urbanized area.  This area attracted development, as the city did not require impact fees there, so only general budget reve­nues were avail­able for improv­ing new facili­ties to adequate standards.  These revenue sources became inade­quate soon after the city adopted the growth manage­ment pro­gram, when state consti­tu­tional initia­tives limited real proper­ty tax rates and spending growth.  The constitu­tional limita­tions made it impossi­ble for the city to finance needed capital im­prove­ments in the urban­ized area, so services and facili­ties deterio­rated or became obsolete.  Another problem was that built-up neighborhoods began to demand higher public facility standards.  Plan­ners had assumed that existing infra­structure in these neighbor­hoods would be sufficient.

Demands for more development put pressure on the urban reserve, an area where the program planned for development later.  Citizens became con­cerned when the city council began to shift too much urban reserve land to the planned urbanizing area, where development could occur.[36]  In 1985, voters adopted an initia­tive that re­quires voter approv­al for any shift from the urban reserve to the planned urbanizing area,[37] but this victory was short-lived.  Voters have approved two projects under this initiative, and later initia­tives intended to limit growth failed.[38] 

A new form of low-densi­ty de­vel­op­ment that escapes the 1985 initiative has also become popular.  Developers took advantage of a city policy that allows clus­tered develop­ments on four-acre lots in the urban reserve.  This type of develop­ment does not need voter approval under the 1985 initiative because it does not require reclassifica­tion from the urban reserve to the planned urbanizing area.  It also has a ready market among affluent homebuyers who seek an exclusive resi­dential environ­ment. 

The city’s response to these problems has been slow and inade­quate.  It has delayed the implementation of ordi­nances that protect sensitive lands and limit the introduc­tion of multifami­ly develop­ment in resi­dential neighbor­hoods.  The city hired its origi­nal consultant late in 1989 to work with a growth management team on improve­ments in the program, but the council rejected their proposals.[39]

The San Diego history illustrates some common prob­lems faced by spatial growth management programs.  First, events outside the program had a major effect, especially on the fiscal side.  Judicial delay in the approval of the assessments for capital facilities is one exam­ple.  Fiscal mea­sures must receive legal approv­al before a city can use them safely, which means that innova­tion, though necessary, is risky.  Innovative regula­tory controls may also face a legal challenge that delays implementa­tion.

The San Diego experience also shows that space management can arouse damag­ing resistance if it modifies market expecta­tions in land development.  San Diego’s tier program conflicts with the Ameri­can prefer­ence for minimum devel­opment con­trols.[40]  The density curve is normally less pronounced than what the San Diego program requires, as develop­ment is usually less intensive in the core and more intensive in outlying areas.  Cutting against this prefer­ence meant, over time, that unexpected coalitions would unite against the program.  Develop­ers tried to undermine the urban reserve, while inner city residents protested the develop­ment and infrastructure problems the program brought.  Political support weak­ened.[41]­ 

In the urban reserve, large lot zoning selected to carry out the program may have made it vulnera­ble to new development.[42]  Because the program preserved this area by limiting growth, its open charac­ter attracted low-density devel­opment, and the voter initiative did not prohibit it.  Although the 1985 initia­tive did slow development in the urban reserve by requiring voter approval to shift land to the planned urbaniz­ing area, voters ulti­mately approved two projects.

The San Diego example also shows that attention to implemen­tation detail is essential.  One problem was that the program made development policy choices in each tier, but did not have a strategy for allocating and phasing devel­opment inside the tiers.[43]  There was no strate­gy, for exam­ple, for allocat­ing develop­ment within the inner urbanized area.  This omission created difficul­ties when the time came to make develop­ment decisions in the tiers, and the city delayed the adoption of a development strate­gy that could deal with these problems.  It finally adopted a plan for the urban reserve in the early 1990s that made strate­gic choices in that area, and that called for the preparation of subarea plans.  The city has adopted some of these plans.[44]

 

III.   The Oregon Urban Growth Boundary Program

 

Oregon’s state land use and urban growth boundary (UGB) programs are well‑known growth management systems.[45]  A set of state plan­ning goals adopted by the state Land Conser­vation and Development Commission (LCDC) are its critical elements.[46]  LCDC re­views local plans and land use regulations and approves them if they comply with the state goals.  Local land use regula­tions and decisions must be consis­tent with the ap­proved plan.  A special tribunal, the Land Use Board of Appeals (LUBA), hears appeals on land use decisions after appellants exhaust all local appeals.[47]

The principal state planning goal that mandates growth management is an urbaniza­tion goal that requires incor­porated municipalities to adopt urban growth bound­aries.  Local govern­ments must draw a clear line between areas that can urban­ize and areas that must remain non-urban.  Local governments must apply seven factors con­tained in the urbanization goal to decide on the size of the urban growth boundary.[48]  In­cor­po­rat­ed munici­pal­i­ti­es apply these fac­tors to des­ig­nate enough growth within their UGB to provide an ade­quate land supply for twenty years.  A UGB can, and usually does, extend beyond munici­pal bound­aries.  The Port­land regional planning agency administers this program in the Portland metro­politan area and is responsible for making deci­sions about the boundary.[49]  The state housing goal, supple­ment­ed by legisla­tion,[50] requires local governments to pro­vide need­ed affordable housing within UGB boundaries.

A key purpose of the state program is the preservation of the Willamette Valley in western Oregon, which has most of the state’s valuable agri­cul­tural land and most of its population.  A complementary agricultural goal requires the preserva­tion of agricul­tural areas, and the statutes autho­rize adoption of exclusive farm use zones to reinforce this goal.[51]  The statutes also require a mini­mum eighty-acre lot size in exclusive agricultur­al zones.[52]  En­force­ment is the primary problem. Growth can occur outside UGBs in agricul­tural areas known as “excep­tion lands.”[53]  These are lands either commit­ted to urban­ization or needed for other uses.[54] 

Observers agree that the preservation of agricultural and other natural resource areas were the primary motivation behind the urbanization goal and the UGB policy.[55]  These priorities mean that the UGB, unlike San Diego tiers, is not primar­i­ly a measure to shape urban growth.  The state planning goals also do not include a strategy for allocating devel­opment within a UGB.

An important measure of the program’s success is the extent to which growth has occurred inside, rather than outside, UGBs.  Unlike San Diego, Portland provid­es public facili­ties and subsi­dies inside the urban growth boundary to encourage develop­ment,[56] although highway con­ges­tion is a prob­lem.[57]  Studies of the UGBs, some limited to Port­land, do find that a sub­stan­tial por­tion of new development has occurred within UGBs.[58]  A study of develop­ment inside the UGBs also showed a sub­stantial amount of develop­ment occur­ring in or next to the urban core, as intend­ed.[59]  Density increases inside the Portland UGB are im­pres­sive, [60] but densities are lower than the program intended.  Lower densi­ties have oc­curred even though zoning that dis­courag­es housing or makes it more cost­ly is prohibited by statute,[61] and though LCDC requires six to ten units per acre for the Portland area on undeveloped, residential­ly-desig­nated lands.[62] 

One of the reasons why higher-density development has not occurred inside the UGBs is that opposition to this type of devel­op­ment has become increasingly common.[63]  Developers became disillu­sioned when they could not build at the expected densities promised by the program at its adop­tion.[64] 

Development has continued to occur at low densities in so-called exception areas[65] outside UGBs, often as spurious farms.[66]  This development is substantial and undercuts the urban growth boundary program, though it has slowed in recent years.[67]  The conversion of land contiguous to UGBs to low-den­si­ty develop­ment is espe­cially trouble­some because it makes the extension of UGBs diffi­cult. If low-density development occurs on land next to the UGB, it will not be available for high-density development when the boundary expands.  The UGB must then expand further than it should have been, and higher-density development must leapfrog over the low-density development that is in the expansion area.  This is the very type of urban sprawl the urban growth boundary program tries to prevent. 

Oregon legisla­tion now allows local govern­ments to desig­nate “urban reserve areas” that are next to UGBs.[68]   These areas provide for the long-term urban expan­sion and cost-effective provi­sion of public facilities and services when the UGB expands.[69]  Local govern­ments are to give priori­ty to urban reserve areas when expanding urban growth bound­aries.[70]

Battle lines over development are more clearly drawn in the Oregon UGBs than in San Diego because the UGB marks the boundary between areas where urban develop­ment can and cannot occur.  In San Diego, large lot zoning in the urban reserve area permits low density develop­ment.[71]  In Oregon the program does not allow urban development outside the growth bound­ary, though low-density residential development in exception areas undermines this objective.  Even so, there are significant price differ­ences between land inside and outside the urban growth bound­ary.[72]  The UGB is not responsi­ble for all of the price increase that has oc­curred inside the boundary,[73] but price increases aggra­vate afford­able housing problems.[74] 

A significant problem in the Oregon UGB program is deciding where develop­ment should occur and at what densities.  Devel­opment at low densi­ties inside the UGBs accelerates demands for boundary expan­sion, which can damage the goal of preserving agricul­tural and forest lands.  Higher densities within the UGB reduce demand for boundary expansion but create opposi­tion from existing neighborhoods.  Hous­ing at high­er den­si­ties inside the UGB can be expen­sive and push lower-income housing out­ward.[75]  Balancing these compet­ing claims re­quires a careful­ly orchestrat­ed strategy, which is more difficult to secure.  The statutes now autho­rize density increas­es within a UGB to meet housing needs as an alternative to a bound­ary expan­sion.[76] 

To help resolve these conflicting pressures, the Portland regional planning agency has adopted an urban growth manage­ment plan as part of its Metro 2040 Growth Concept, although opposi­tion has slowed implementa­tion.[77]  The plan requires local gov­ern­ments to in­crease housing densi­ties and meet housing capacity stan­dards set by the plan.[78]  The Growth Concept, and the stat­ute giving priority to urban reserve areas in boundary expan­sions, are the bases for agency regula­tions for the review of growth bound­ary expansions.  These regulations supplement the state planning goals.

The regulations create a category of “first tier urban reserves” that have a priority in boundary expansions because they are areas where urban services are most effectively provid­ed.[79]  A proposed bound­ary expansion amendment also requires an urban reserve plan that provides for an average minimum residen­tial density of ten dwelling units to the acre and a diversity of housing stock.[80]  Plans must ensure the orderly, economic and efficient provision of urban servic­es through an­nex­ation to a city, a city and county agreement on planning and zon­ing,[81] or an urban services agreement.[82]  These regu­la­tions reinforce the UGB pro­gram by giving priority to in-boundary expansions to adjacent lands and by requiring reason­able densi­ties with assur­ances that adequate services are available.

The Oregon experience shows how expectations about develop­ment opportunities and coalition shifts can affect program perfor­mance.  The devel­opment industry wel­comed the UGB because it seemed to provide a commitment to higher-density develop­ment inside UGBs.  When opposition arose within the UGB, the industry felt betrayed.  Outside the UGB the agricultur­al sector, though it usually supports the conversion of farm­land, joined envi­ron­men­talists in a cam­paign to preserve even marginal agri­cul­tural lands from develop­ment.  The UGB may have become a symbol that polarizes opposing interests and prevents meaning­ful consen­sus on growth manage­ment strategies.

 

IV.              Defending and Improving Strategies for Growth Management

 

Problems in the San Diego and Portland space management programs do not diminish their importance as major innova­tions in land use controls.  Many problems are political.  Opposition arose when program costs not apparent up front became obvious.  Opposi­tion hard­ened in Portland, for exam­ple, to expansion of the growth boun­dary and more intensive develop­ment within it.[83]  Framing a program around environ­mental protec­tion, as in Oregon, can also encourage a rigid defense of environmental areas that pre­vents compro­mise.[84]  In San Diego, concessions were made at the beginning, politi­cal support diminished, and the devel­opment community applied pressure to weaken the program.[85]  Voters re­sponded with initia­tives that limited the city’s freedom to make program chang­es, but later initiatives lost and the use of the ballot box under­scores the loss of political support.[86]  The local basis for the program may also make it more vulnera­ble.  In Oregon, growth management through growth bound­aries is state-mandated, popular support has contin­ued, and statewide initia­tives to weaken the program have lost.

Improvements in growth control techniques cannot eliminate political opposition, but they can improve political acceptance by providing clearer and more effec­tive strategies for growth management.  The San Diego and Oregon experience shows that growth management programs need improvement in their strategies for subor­dinate, second-level poli­cies.  The San Diego tiers and the Oregon UGBs provide a framework for growth, but subordi­nate strategies are not as well devel­oped.

 

A.     The Legal Defense of Growth Restrictions

 

1.      Some Conceptual Problems

 

A perennial problem for growth management programs is to develop strategies for limiting development where the program does not want development to take place.  Traditional land use con­trols cannot accomplish this objective because they are usually lenient.  Local governments do not use zoning and other con­trols to place limits on where develop­ment can occur, impose boun­daries that iden­tify growth opportunities, or forceful­ly direct develop­ment to core areas.  The San Diego and Oregon programs made major changes in this system.  They adopted boundaries that decide where develo­pment can and cannot occur, and deliberately directed development to the inner core. Strate­gies of this kind can create windfalls for wipeouts problems because they dramati­cal­ly affect development opportu­nities and land prices on each side of the boundary line.  These problems, in turn, can create signifi­cant new legal diffi­cul­ties for the development control sys­tem.[87]

Legal problems are most difficult on the side of the bound­ary where development cannot occur.  Development restrictions raise the familiar cry that one group of land­owners must accept deep losses in property value to benefit the rest of the communi­ty.  This is a well-known takings problem.

It is significant that there has not been a successful legal attack against growth restrictions in either San Diego or Port­land.  One reason may be the tradeoffs in develop­ment opportuni­ties these programs provide.  They restrict devel­opment in some areas but provide development opportunities elsewhere.  Another explanation may be that the programs provided enough opportu­nities for develop­ment so that legal attacks on growth restric­tions are not necessary.  Shifts of urban reserve land in San Diego to allow their develop­ment, and development opportuni­ties on exception lands in Oregon, are examples.

The boundary may also affect expectations in ways that diminish taking of property objections.  The urban growth bound­ary in Portland, for example, must allow enough land for twenty years of growth.  Since the boundary is likely to expand when this land supply is no longer available, adjacent land near the boundary has a good expec­ta­tion of development in a reasonable time after twenty years.[88]  The question is whether a restriction on develop­ment for this period is a taking of proper­ty.  If courts will accept that a delay in the develop­ment of property of this length is not a taking, then restrictions on development in growth manage­ment programs are safe from a takings attack.

The Ramapo case upheld delays in development to carry out a growth manage­ment program.[89]  There, a growth management program deferred growth for as long as eighteen years and permitted develop­ment only when desig­nated public facili­ties and services were available.  The New York Court of Appeals rejected a takings claim because it held the delay was part of a reasonable program for controlling growth.[90]  A court could apply this kind of reason­ing to delays in development that occur in areas near growth boundaries because those delays are also limited in time.  How much delay a court will accept is another ques­tion.

Supreme Court cases decided since Ramapo raise other ques­tions.  It is now clear the courts require compensation for a tempo­rary taking for the period a regulation was in effect before a court holds it violates the takings clause.[91]  In addi­tion, the Court’s Lucas deci­sion held a land use regula­tion that does not allow an economically viable use is a taking per se.[92]  That case found a per se taking when a beach setback in a coastal management program deprived a landown­er of all eco­nom­i­cally viable use of his land.[93]  The Court would not consid­er the purpose state­ment in the act as a basis for upholding the re­striction.[94]  The Lucas per se takings rule, and the re­quire­ment that compensation is payable for a temporary taking when a land use regulation is unconstitutional, could invali­date tempo­rary re­stric­tions on development in growth bound­ary pro­grams.  If the program does not allow any development on land outside the growth bound­ary, a court could find a temporary taking for the period during which this restriction was in effect.[95]

In areas further from the boundary line, the delay in development may be substantial, so an argument that the program requires only a temporary delay in development may not apply.  In these areas, however, the economics of a taking claim may dis­courage a takings attack.  If the landowner believes the dis­counted development value of her land at a future date is worth more than what she might recover as compen­sation in a takings suit then she will not sue.  Discounted value may be higher because land values will rise as development occurs in adjoining and surrounding areas.[96]

If a landowner brings a takings claim, the critical question is whether the land use restriction is a per se taking because it denies all economically viable use of the property.  What is a denial of economically viable use is not clear.  In Lucas, the Court did not decide whether there must be a develop­mental use of the property to avoid a claim that a regulation does not allow an economically viable use.[97]  Some cases have held the key ques­tion is whether there is a competi­tive and realistic market for the land that is subject to re­stric­tion.[98]  This means there must be a market of buyers who are willing to buy the land for development, not for speculation.  It does not mean the land use regulation allows a developmental use of the property.  If this market exists, there is no taking, but this view may not be a correct interpreta­tion of the Supreme Court’s Lucas deci­sion. 

 

2.      Control Techniques for Limiting Development

 

This discussion of takings problems in growth restriction areas can provide guidance on the type of controls that can limit development yet not create takings problems.[99]  Exclu­sive agri­cul­tural zoning, as in Oregon, is one op­tion.  Agricultural pro­tection is clearly a legitimate governmental objective,[100] and the courts uphold agricultural zoning against takings claims when land is present­ly used or suitable for agricul­ture.[101]  A Lucas per se taking does not arise.

Controls that re­strict development in sensitive environmen­tal areas are other possibilities.  These controls can present takings problems[102] under the Lucas deci­sion[103] because they of­ten prevent any developmental uses, but this problem has not yet been serious.  In the wetlands cas­es, for exam­ple, courts have dis­missed tak­ings claims where the property was not all wetlands, and the land­own­er could carry out an economically viable use on that part of the land.[104]  Takings prob­lems have arisen only when a permit denial or regula­tion pro­hib­its develop­ment on small single lots.[105]  This problem should not occur in undeveloped areas outside growth bound­aries where land holdings are likely to be extensive.

When agri­cultural zoning or environmental land use regula­tions are not an option, growth management programs may have to rely on large lot, single-family residential zoning, as in San Diego.  Large lot zoning can be an effec­tive restriction on development when it zones densities so low that they discourag­e devel­op­ment, but that kind of zoning can raise legitimacy and takings prob­lems.

Courts may accept large lot zoning at low densities when it imple­ments a growth manage­ment program contained in a comprehensive plan.[106]  An important pre-Lucas Maryland case upheld re­stric­tive large lot zoning that implemented a growth manage­ment pro­gram in Montgom­ery County, next to Washington, D.C.[107]  The county downzoning required two acre zoning to protect watersheds and a green belt in a fifty-square mile area around a satel­lite commu­ni­ty desig­nated in a master plan.[108]  The master plan promoted the physical isolation of the communi­ty from urban sprawl, and carried out a corridor plan adopt­ed for the metropol­i­tan region.[109]  The court relied on the purpose of the master plan to hold that downzoning was not a taking of proper­ty.[110]

Zoning of this type is more problematic after Lucas because a court can hold that it deprives a land­owner of all economically viable use of her land.  This issue remains open, though a post-Lucas Maryland case upheld  comprehensive five acre zoning adopted to implement a comprehensive plan.[111]  This zoning protected the Baltimore watershed from unsuit­able develop­ment and prevented urban sprawl.[112]  The court held the Lucas per se taking rule did not apply because the zoning re­striction did not leave the property economical­ly idle.[113]

Densities at two or five acres, which the Maryland cases approved, may prevent develop­ment effectively in areas permanently restricted from growth in growth management programs.[114]  Low residen­tial densities may still be vulner­a­ble to a takings at­tack, though judicial tolerance for very low density zoning when used to implement a growth manage­ment program may be higher than expect­ed.[115]  Low-density zoning may also provide an escape hatch for affluent housing in areas where growth is not supposed to occur.

Transfer of development rights (TDR) pro­grams are another strategy that can help avoid Takings Clause claims in areas where a growth management program prohibits develop­ment.  TDR programs help avoid these problems because they provide for the transfer of develop­ment rights from restricted areas to areas where develop­ment can occur.[116]  Compensa­tion paid by buyers of rights to sellers can fully or partially mitigate a takings claim.[117]  The best example of a TDR program that supports growth management is the Montgom­ery County, Maryland program that protects the county’s agri­cultur­al area from develop­ment.[118]  Nev­er­theless, TDR programs in exten­sive agricul­tur­al or natural resource areas are diffi­cult to implement if the market will not generate the trades necessary to provide adequate compensa­tion to sellers of rights.  The volume of rights for sale in restricted areas must be in balance with the growth allowed in growth areas to make a TDR program work.[119]  If this balance does not occur, additional public inter­vention through development rights banks that can buy and hold develop­ment rights may be necessary, but banks may be expen­sive to create and difficult to manage.[120]  Montgom­ery County may be unique because its location next to the national capital creates a strong demand for office space.  This demand supports the market for development rights.

 

B.     Strategies to Intensify Development Where it is Needed

 

Space management programs usually encourage higher density development in areas inside the boundaries to offset restric­tions on development outside the boundaries.  Higher density develop­ment often occurs as infill in existing neighborhoods and usually requires upzonings.  Residents of these neighborhoods may ob­ject if they believe higher densities will have a negative effect on their neighborhoods and may attack upzon­ing for higher density development as spot zoning.  Courts strike down upzonings as spot zoning if they are incom­patible with the surrounding area and do not provide a public bene­fit.[121] 

This problem has two dimensions.  One problem is at the design and scale level.  A zoning ordinance may allow intensive development in existing neighborhoods with poor design or out of scale with its environment.  Neighbors then resist and oppose proposals for new development.  Attention to design and scale in land development regulations can allow more intensive development that does not destroy existing neighborhood charac­ter.

Even good design is not enough if higher density development is the real objection, which is often the case.  A growth manage­ment strategy for urbanized areas must provide a framework for new development that existing residents can accept.  Adequate design review, density floors and ceilings in residen­tially designated areas, periodic review of how the munici­pality has dealt with new residential uses, and the funding of infra­struc­ture “banks” the munici­pality can draw on for capital facilities illustrate measures that local governments can consid­er.[122] 

Local governments may also have to face the impact fee issue in built-up areas, though levying impact fees in these areas may make it more difficult to attract new development.  The basic issue is fairness, and deciding when a municipality can shift the cost of new capital facilities to the private sector.  If new development in estab­lished neighbor­hoods creates a demand for new or improved facilities, the case for shifting costs to the private side is compel­ling.[123]

Municipalities also need to adopt plans for the devel­op­ment of urban­ized areas that decide where new develop­ment will go and at what densities.  There are at­tempts to do just this in plans, such as urban village and urban center plans, which allo­cate new devel­opment within cit­ies.[124]  Courts will uphold upzonings that im­ple­ment a comprehensive plan against objec­tions that they improp­erly favor an individual land­owner at the expense of his neigh­bors.[125]  Specifying the intensity of growth that must occur within growth boundaries can also help.  Model legisla­tion proposed by the American Planning Association requires urban growth areas to contain land at “mini­mum densities and intensi­ties.”[126]  They must accommo­date a desig­nat­ed percentage of the growth expected to occur within the region or county in which the urban growth area is located.[127] 

Programs to allow new development in urbanizing areas are less difficult to manage.  Raw land converts to development in this process, and usually there are no neighbors who can object that devel­op­ment is too intensive.  Techniques such as floating zones and planned unit development regulations can autho­rize new develop­ment as it occurs, and require compliance with the growth manage­ment program.

Assuring adequate public facilities in urbanizing areas is a more difficult problem.  In San Diego and Portland, new develop­ment has overwhelmed public facili­ties, espe­cially highways, despite attempts to ensure adequate public facili­ties as growth occurs.  The courts finally upheld the facili­ties benefit assess­ment in San Diego, but exactions on develop­ment are more diffi­cult to defend follow­ing Supreme Court deci­sions that place the burden on municipalities to justify exac­tions.[128]  Some trans­por­tation facilities, such as highway inter­changes and mass transit, arguably are a public responsibil­ity and not subject to exaction.

At­tempts to resolve this problem by requiring adequate public facilities before a local government approves new develop­ment do not always succeed.  Defining adequate service levels is diffi­cult, matching incremen­tal development to public facility plan­ning is not easy, and service deficiencies have encouraged sprawl by forcing develop­ment to outlying ar­eas.[129]  A similar “concurrency” requirement that likewise attempts to require adequate facilities when new development receives approval has also proved difficult to manage.[130] 

There is no magic fix that can ensure the provision of necessary capital facilities and services in growth management programs.  There must be adequate public facilities budgeting, firm fiscal support and develop­er exactions that have an adequate legal basis.

 

V.                 Conclusion 

 

Space management strategies that dramatically shape the pattern of development are powerful control measures in growth manage­ment programs.  Their primary purpose is to designate areas where growth cannot occur and where it is encouraged.  Like other land use pro­grams with single-issue or limited objec­tives, they are overlays on existing land development regulations.  They may pay some attention to develop­ment densi­ties in areas where growth can occur and to development restric­tions in areas where growth cannot occur.  They do not pay enough attention to more detailed subordinate strate­gies that can manage growth in growth-desig­nated areas and prohibit growth where the program re­stricts it. 

This strategic failure makes it difficult to strike a program balance that can link the decision on how much area to commit to growth with the decision on how much area to restrict.  Finding the correct balance between growth and growth restriction is the key that will determine the success or failure of a space management strategy.

The imperative of managing change is another important lesson from San Diego and Oregon.  Planning for growth management before the fact, in a political environment that may be uncertain at best, is clearly not the easiest task.  Governments must adopt the most effective strategies available when they create these programs, but they must also monitor and respond to change.  The alternative, as the Governor of Oregon warns, is the impossible.

 

 



* Stamper Professor of Law, Washington University in St. Louis.  The author would like to thank Nico Calavita, Bob Einsweiler, Frances Foster, Bob Freilich, Wendie Kellington, Stuart Meck, Doug Porter, and Ed Sullivan for their valuable comments on an earlier draft of this article.  Of course, the author’s analysis and opinions are his own.

[1] The text adopts the definition of sprawl used throughout Transit Cooperative Re­search Program, Rep. 39, The Costs of Sprawl—Revisited (1998).  See also Robert W. Burchell & Naveed A. Shad, The Evolution of the Sprawl Debate in the United States, 5 Hastings West-Northwest J. Envtl. L. & Pol’y 137, 140-42 (1999) (defining sprawl as “low-density residential and nonresidential intrusions into rural and undeveloped areas, and with less certainty as leapfrog, segregated, and land-consuming  in its typical form”).

[2] “Urban sprawl” means urban development or uses which are located in predominantly rural areas, or rural areas inter­spersed with generally low-intensity or low-density urban uses, and which are characterized by one or more of the following conditions: (a) The premature or poorly planned conversion of rural land to other uses; (b) The creation of areas of urban development or uses which are not functionally related to land uses which predominate the adjacent area; or (c) The creation of areas of urban development or uses which fail to maximize the use of existing public facilities or the use of areas within which public services are currently provided.  Urban sprawl is typi­cally manifested in one or more of the following land use or development patterns: leapfrog or scattered development; ribbon or strip commercial or other development; or large expanses of predominantly low-intensity, low-density, or single-use develop­ment.  See Fla. Admin. Code Ann. § 9J-5.003(134) (1999).

[3] Although the anti-sprawl position has consider­able appeal, defenders of sprawl dispute the arguments that sprawl threatens natural resources and creates higher government costs, and deny that it is a serious social problem.  See, e.g., Samuel R. Staley, The Sprawling of America: In De­fense of the Dynamic City 14-15 (1999) (claiming that the “sprawl index” is declin­ing, that urban development does not threaten agriculture, that the effect of suburbanization on local govern­ment costs is exaggerat­ed, and that air quality deteriorates at higher densi­ties).  See generally, e.g., Peter Gordon & Harry W. Richard­son, Are Compact Cities a Desir­able Planning Goal?, 63 J. Am. Plan. Ass’n 95 (1997) (ex­plain­ing benefits of urban sprawl, including oppor­tuni­ties for infill development).  See also Ivonne Audriac et al., Ideal Urban Form and the Dilemma of the Good Life: Florida’s Growth Management Dilemma, 56 J. Am. Plan. Ass’n 470 passim (1990) (noting that sprawl is a response to market preferences, and that attempts to control it will likely drive up land and housing values); Gregg Easterbrook, Suburban Myth, New Repub­lic, Mar. 15, 1999, at 18 (arguing that sprawl is not entirely negative because besides the fact that the alternatives and proposals to remedy sprawl are unrealistic to implement, people actually enjoy some of the effects of sprawl).

[4] See Reid Ewing, Is Los Angeles-Style Sprawl Desir­able?, 63 J. Am. Plan. Ass’n 107, 117-18 (1997).  See generally Transit Cooperative Research Program, supra note 1 ; Sympo­sium, Urban Sprawl, 29 Urb. Law. 157, 158-251 (1997) (citing specific examples of increased costs and pollution caused by sprawl).

[5] See generally Real Estate Research Corp., The Costs of Sprawl (1974). 

[6] See, e.g., Alan A. Altshuler, Book Review, 43 J. Am. Plan. Ass’n 207, 208 (1977) (asserting that the study underestimated demand for services from higher-density development and mixed density and unit size effects).  See generally, e.g., Duane Windsor, A Critique of The Costs of Sprawl, 45 J. Am. Plan. Ass’n 279 (1979) (book review) (commenting on the failure to disentangle density from other factors and a failure to credit sprawl as a response to market preferences).

[7] See Transit Cooperative Research Program, supra note 1 , at 46-49.  See also Robert W. Burchell & David Listokin, Land, Infrastructure, Housing Costs and Fiscal Impacts Associated with Growth: The Literature on the Impacts of Sprawl v. Managed Growth 10 (1995) (claiming that planned development and growth can result in reduced costs to communities); Jerry Weitz & Terry Moore, Develop­ment Inside Urban Growth Bound­aries: Oregon's Empirical Evidence of Contigu­ous Urban Form, 64 J. Am. Plan. Ass’n 424, 430-34 (1998) (asserting that sprawl and scattered development costs more than contiguous and planned development because it is an inefficient use of land and resources).  See, e.g., The Sierra Club, The Dark Side of the American Dream: The Costs and Conse­quences of Subur­ban Sprawl (visited Nov. 14, 1998) <http://www.sierraclub.org/sprawl/report98/costs.html#who> (“Providing services to new development has grown so costly in Prince William County, Virginia, near Washington, D.C., that even though the county has the highest property-tax rate in the Commonwealth, every new house brings a $1,688 shortfall.”).

[8] See Transit Cooperative Research Program, supra note 1 , at 50-52.

[9] See Golden v. Ramapo Planning Bd., 285 N.E.2d 291, 301-03 (N.Y. 1972), appeal dismissed, 409 U.S. 1003 (1972). 

[10] See Eric Damian Kelly, Community Growth: Policies, Tech­niques, and Impacts 20 (1993). 

[11]  See Edward J. Kaiser & David R. Godschalk, Twentieth Century Land Use Plan­ning, 61 J. Am. Plan. Ass’n 365, 365-66 (1995).

[12]  See Eric Damian Kelly, Planning, Growth, and Public Facili­ties: A Primer for Local Officials 16 (1993).

[13]  For further discussions of urban growth boundary programs see Tom Daniels, When City and Country Collide 187-209 (1999), V. Gail Easley, Staying Inside the Lines: Urban Growth Bound­aries, 16-27 (1992), Douglas R. Porter, Managing Growth in America’s Communi­ties 61-69 (1997), and Ned Farquhar, Zoning Fall­out: The Implications of Urban Growth Boundary Desig­nations, Zoning News, Mar. 1999, at 1.

[14]  For an early account of this program see generally Daniel R. Mandelker, Green Belts and Urban Growth (1962).

[15] See generally Dowell Myers & Alicia Kitsuse, The Debate Over Future Density of Development: An Interpretive Review (1999) (discuss­ing the density issue and conflicting reports on the impact of sprawl on urban develop­ment in California) (on file with author).

[16] For more in-depth commentary on the San Diego program see generally Robert H. Freilich, Battle Against Sprawl: Smart Growth Systems Using the Ramapo Approach (1999); Douglas R. Porter et al., Profiles in Growth Management 81-87 (1996); Nico Calavita, Growth Ma­chines and Ballot Box Planning, 14 J. Urb. Aff. 1 (1992) [herein­after Calavita, Ballot Box]; Douglas R. Porter, San Diego’s Brand of Growth Manage­ment: A for Effort, C for Accom­plishment, 48 Urb. Land, at 21 (1989) [hereinaf­ter Porter, Effort].  See also Nico Calavita, Vale of Tiers, Plan­ning, Mar. 1997, at 18  (criticizing San Diego’s growth management program as well-intentioned but ineffective against development interests).

[17] Professor Robert H. Freilich prepared the program as consultant to the city of San Diego.  Professor Freilich was renowned for recently having won a major case, Golden v. Ramapo Planning Bd., 285 N.E.2d 291, appeal dismissed, 409 U.S. 1003 (N.Y. 1972), in the New York Court of Appeals, thereby sustaining a growth manage­ment program he had developed for the Town of Ramapo (a suburb of New York City).  The Ramapo program allowed new development only when adequate public facilities and services were available.

[18] See Robert H. Freilich, A Growth Management Program for San Diego (1976) (on file with author).

[19] Id. at 2-5.

[20] See John W. Witt & Janis Samartino-Gardner, Growth Manage­ment v. Vested Rights, One City’s Experience: A Case Study of San Diego, 20 Urb. Law. 647, 650 (1988).

[21] Professor Freilich stated that another purpose of the program was to organize growth in the planned urbanizing tier through a transportation corridor ap­proach.  See generally Freilich, supra note 16 .

[22] See Freilich, supra note 18 , at 4-1, 5-1, 6-1.

[23] See id. at 5-2 (“The objective in identifying . . . [planned urbanizing] areas is to channel new growth into them in an orderly, logical sequence that enables the City to expand facilities and services commensurate with growth.”). 

[24] Professor Freilich did not propose a transfer of development rights program for the environmental tier, probably because development rights transfer was then a new and untried idea.  For two discussions of transfer of development rights and other techniques the city could have used in the environmen­tal tier, see generally Rick Pruetz, Saved By Development (1997) and Jerold S. Kayden, Market-Based Regulatory Approach­es: A Com­parative Discus­sion of Environ­mental and Land Use Techniques in the United States, 19 B.C. Envtl. Aff. L. Rev. 565 (1992).

[25] See Witt & Samartino-Gardner, supra note 20 , at 651.

[26] See Freilich, supra note 18 , at 6-19,

[27] For an analysis of the legal issues suggesting statutory authority and constitutional problems in the program see generally John M. Winters, An Independent Legal Analysis of a Growth Management Program for San Diego (1978) (on file with author).

[28] See, e.g., Ann Louise Strong, Trans­fer of Develop­ment Rights to Pro­tect Water Resources, Land Use L. & Zoning Dig., Sept. 1998, at 3 (discussing TDRs generally, and specifically considering the use of TDRs in four water resource protection programs in the United States).  See generally, e.g., Jeanne S. White, Beat­ing Plow­shares into Townhomes: The Loss of Farm­land and Strategies for Slow­ing Its Con­ver­sion to Nonagricul­tural Uses, 28 Envtl. L. 113 (1998) (discussing the importance of farming to communities and the tools being used to preserve farmlands in several areas).

[29] See Calavita, Ballot Box, supra note 16 , at 7-8.

[30] See id. at 16.  See also Interview with Kenneth E. Sulzer, Executive Director, San Diego Association of Govern­ments (Jan. 25, 1999) (noting that habitat protec­tion areas adopted under the Endangered Species Act, 16 U.S.C. §§ 1531-1544 (1994 & Supp. IV 1998), also restrict growth).  See generally Craig Manson, Natural Communities Conserva­tion Planning: California's New Ecosystem Approach to Biodiversity, 24 Envtl. L. 603 (1994) (discussing California’s implementation of the Natural Community Conservation Planning program and the possibility of a balance between endangered species and economic concerns in communities).

[31] See Letter from Nico Calivita, Professor, San Diego State University (Mar. 31, 1999) [hereinafter Calavita Letter] (on file with author).

[32] See J.W. Jones Co. v. City of San Diego, 203 Cal. Rptr. 580 (Cal. Ct. App. 1984).

[33] See Calavita, Ballot Box, supra note 16 , at 11 (noting that the considerable time lag before facilities were actually built was a result of the lead-time needed to plan, design, engineer, and actually construct public improvements).

[34] See Porter, Effort, supra note 16 , at 25.

[35] See Calavita, Ballot Box, supra note 16 , at 16.

[36]  See Roger W. Caves, Land Use Planning: The Ballot Box Revo­lution 140-53 (1992).

[37]  The hardening of public opposition to development in areas reserved for develop­ment occurred in both San Diego and Portland.  Without careful examination of growth trends and land availability, however, it is difficult to determine whether public opposi­tion was justified.  In Oregon, moreover, popular initia­tive could not change the program because it was mandated by state law.  See id. at 152-53.

[38]  See Telephone Interview with Nico Calavita, Professor, San Diego State University (Jan. 20, 1999) [hereinafter Calavita Interview].  In November 1998 voters turned down an initiative that would have established an urban growth boundary for the county.  See id.; Caves, supra note 36 , at 153-62.

[39] See Calavita, Ballot Box, supra note 16 , at 17.  The proposals included citywide impact fees, level of service (LOS) standards and a capital facilities plan to meet LOS standards, and phasing of new devel­opment if it exceeded the demand for transportation facilities beyond what could by accommodated on the basis of the capital facilities plan.  In 1987, the city had also adopted an interim development ordinance that set limits on residential construction for eighteen months.  See id. at 12.

[40] See Dan Eggen, Local Controls Fail to Restrict Growth, Wash. Post, Aug. 9, 1998, at B1.

[41] See Porter, Effort, supra note 16 , at 22-24.  The need to seek voter approval of initiatives to limit the city council’s control over the program indicates the extent to which interest groups perceived a lack of political support.  See generally Chris­topher Leo et al., Is Urban Sprawl Back on the Political Agenda? Local Growth Control, Regional Growth Manage­ment, and Politics, 34 Urb. Aff. Rev. 179 (1998) (arguing that attempts to control sprawl have failed, in large part, because regional growth management initiatives have not successfully been distinguished from unpopular growth controls).

[42] Large lot zoning is a problematic zoning technique, and courts have found it unconstitu­tional when used for exclusionary purposes.  See National Land & Inv. Co. v. Kohn, 215 A.2d 597, 612-13 (Pa. 1965).  This problem does not seem to have arisen in San Diego.

[43] Developing this kind of strategy was not part of the work program for the growth management plan.  See Freilich, supra note 18 , at 1-5.

[44] See Calavita Letter, supra note 31 .

[45] For surveys of the Oregon program, see generally American Planning Ass’n, Legisla­tive Guide­book Phases I & II, Interim Edition 6-43 (1998); Gerrit Knaap & Arthur C. Nelson, The Regulated Land­scape: Lessons on State Land Use Planning from Oregon (1992); Carl Abbott, The Portland Region: Where City and Suburbs Talk to Each Other—and Often Agree, 8 Hous. Pol’y Debate 11 (1997); Robert L. Liberty, Oregon’s Compre­hensive Growth Management Program: An Imple­menta­tion Review and Lessons for Other States, 22 Envtl. L. Rep. (Envtl. L. Inst.) 10,367 (1992); and Edward J. Sullivan, Marking the Twenty-Fifth Anniversary of SB 100, Or. L. Rev. (forth­coming).  For a critique of state land use systems, see generally Jerry Weitz, Evolution of State Sponsored Land Use Planning (forthcoming 1999).

[46] These goals were legislatively mandated upon creation of the UGB.  See Or. Rev. Stat. §§ 197.225-.245 (1991).

[47] The term “land use decision” is defined in id. § 197.015(10), and a rich and varied case law that tends to lead the Land Use Board of Appeals to review most local actions affecting land use in case of doubt.

[48] The seven factors are:

 

(1) the demonstrated need to accommodate long‑range urban popula­tion growth requirements consistent with LCDC goals;

(2) the need for housing, employment opportunities, and livabil­ity;

(3) the orderly and economic provision for public facilities and services;

(4) the maximum efficiency of land uses within and on the fringe of the existing urban area;

(5) the environmental, energy, economic, and social conse­quenc­es;

(6) the retention of agricultural land as defined, with Class I the highest priority for retention and Class VI the lowest priority; and

(7) the compatibility of the proposed urban uses with nearby agricultural activi­ties.

 

Department of Land Conservation & Dev., Oregon’s Statewide Planning Goals and Guidelines (1995).  The first two factors are called the “need” factors.

[49] See Or. Rev. Stat. §§ 197.301-.302.

[50] The housing requirements are at id. §§ 197.303-.314.  Section 197.307(3)(a) provides an example of one such requirement:

 

When a need has been shown for housing within an urban growth boundary at particular price ranges and rent levels, needed housing, includ­ing housing for seasonal and year-round farmworkers, shall be permitted in one or more zoning dis­tricts or in zones described by some comprehensive plans as overlay zones with sufficient buildable land to satisfy that need.

 

[51] See id. § 215.203.

[52] See Or. Rev. Stat. § 215.780 (Supp. 1998).  Smaller lot sizes are allowed as exceptions under strict conditions.  See id. §§ 215.780(2)(a)-(b).  The statute also requires an 80-acre lot size minimum for forest zones, and a 160-acre minimum for the rangeland agricultural area.  See id. §§ 215.780(1)(b)-(c).

[53] See §§ 197.732(1)(a)-(c).  See also 1000 Friends of Oregon v. Land Conservation and Development Commission, 724 P.2d 268, 279 (Or. 1986) (explaining the three types of exceptions local governments can use under sections 197.732(1)(a)-(c)).

[54] See Or. Rev. Stat. §§ 197.732(1)(a)-(c) (1991 & Supp. 1998).

[55] See Wendie L. Kellington, Oregon’s Land Use Program Comes of Age: The Next 25 Years, Land Use L. & Zoning Dig., Oct. 1998, at 3-4; Weitz & Moore, supra note 7 , at 431.  But see Easley, supra note 13 , at 5 (quoting purposes of the UGB for Salem, which also include the efficient and economic provi­sion of services, and the matching of services with population growth).

[56] See Calavita Interview, supra note 38 .

[57] See Kellington, supra note 55 , at 4.

[58] See, e.g., id. (indicating that the Portland UGB is essentially full); Weitz & Moore, supra note 7 , at 424 (“[M]ore than 90 percent of Oregon’s new residents between 1980 and 1989 located inside UGBs.”).

[59] See Weitz & Moore, supra note 7 , at 429 tbl.3.

[60] See Rachel L. Schowalter, Reuse, Restore, Recycle: Historic Preservation as an Alternative to Sprawl, 29 Envtl. L. Rep. (Envtl. L. Inst.) 10,418, 10,421 (1999) (“Since Portland, Oregon, adopted its urban growth boundary in 1975, Portland’s population has grown by almost 50 percent, but it has used only 2 percent more land.”).

[61] See Or. Rev. Stat. § 197.307(6) (1998).  The statute provides that local governments must also have “approval standards” and “spe­cial conditions” which are “clear and objective and shall not have the effect, either in themselves or cumulatively, of dis­couraging needed housing through unreasonable cost or delay.”  Id.  See also Rogue Valley Ass’n of Realtors v. City of Ashland, LUBA No. 97-260 (Or. Land Use Bd. App. Sept. 24, 1998) (invalidating approval standards in a steep slope ordinance).

[62] See Or. Admin. R. 660-007-035 (1998).

[63] See Editorial, Growth Land-Use Plans Must Be Enforced, Atlanta J., Nov. 12, 1998, at A26.

[64] See Interview with Duane Desiderio and Grant Madsen, Representatives of the National Association of Homebuild­ers, Dallas, Tex. (Jan. 13, 1999).

[65] Or. Rev. Stat. §§ 197.73(1)(a)-(c) (1991 & Supp. 1998).  These are areas that are already developed for rural residential homesites or for commer­cial or industrial uses, or are areas “committed” to development because of parcelization or installation of services or because surrounding development makes farming and forestry impracticable.  See Liberty, supra note 45 , at 10,387.  See also 1000 Friends of Oregon v. Land Conservation & Dev. Comm’n, 724 P.2d 268, 277-79 (Or. 1986) (explaining genesis, applica­tion, and mechanics of exception areas).

[66] See Nyran Rasche, Protecting Agricultural Lands in Oregon: An Assessment of the Exclusive Farm Use Zone System, 77 Or. L. Rev. 993, 997 (1998).

[67] See Interview with Edward J. Sullivan, Attorney, Portland, Or. (Jan. 31, 1999).

[68] See Or. Rev. Stat. § 195.145 (Supp. 1998).  The statute does not specify the techniques that local govern­ments must use to carry out this purpose, but states instead that the Land Conser­vation and Development Commission “shall provide to local governments a list of options, rather than prescribing a single planning technique, to assure the efficient transition from rural to urban use in urban reserve areas.”  Id.  Designation of urban reserve areas is voluntary, but the LCDC may require a designation in major metropolitan areas.  Prohibiting the subdivision of land is one technique that can keep urban reserve land clear for future development.

[69] See id. § 195.145(4).

[70] See id. § 197.298(1)(a).

[71] See generally Freilich, supra note 18 .

[72] See Gerrit J. Knaap, The Price Effects of Urban Growth Bound­aries in Metropolitan Portland, Oregon, 61 Land Econ. 26, 32-33 (1985); Arthur C. Nelson, Using Land Markets to Evaluate Urban Contain­ment Programs, 52 J. Am. Plan. Ass’n 156, 160 (1986).

[73] See Knaap, supra note 72 , at 31; Nelson, supra note 72 , at 162.

[74] Housing affordability is problematic because of the prevail­ing, fairly low, average income in the area.  The rise in housing prices is also due, in part, to the emergence of a fairly high-income segment of the labor force that wants large homes, even on small lots.  See Letter from Douglas R. Porter, President, Growth Management Institute (Feb. 22, 1999) (on file with author).

[75] See id.

[76] See Or. Rev. Stat. § 197.296(4)(b) (Supp. 1998).  Model legislation proposed by the Ameri­can Planning Associa­tion requires monitoring of an urban growth bound­ary to ensure that land supply remains ade­quate.  See American Planning Ass’n, supra note 45 , § 6.201.1(9).

[77] See Robin Franzen & Brent Hunsberger, Have We Outgrown Our Approach to Growth?, Oregonian, Dec. 13, 1998, at A1.

[78] See Metropolitan Regional Service District, Urban Growth Management Functional Plan (last modified Feb. 2, 1999) <http://www.multnomah.lib.or.us/metro/growth/tfplan/ funcplan.html>.

[79] See Portland, Or. Metropolitan Code § 3.01.010(e) (1993) available at <http://www.multnomah.lib.or.us/metro/glance/metcode/metcode1.html>.

[80] See id. §§ 3.01.012(e)(4)-(5).

[81] See id. § 3.01.012(e)(1).

[82] See id. § 3.01.012(e)(2).  In addition, the expan­sion must assist in compli­ance with the Growth Concept or other statuto­ry or regula­tory requirements for land within an urban growth bound­ary.  See id.  

[83] Opposition to high-density development near transit stations is an example.  See Douglas R. Porter, Transit-Focused Development: A Prog­ress Report, 64 J. Am. Plan. Ass’n 475, 485 (1998) (noting that transit-focused development has encountered neighborhood resis­tance and little governmental leadership in four regions).  Porter notes that some transit-oriented develop­ment has occurred in the Portland area.  See id.

        In San Diego, transit-oriented development has been limited by the location of transit lines, limited land availability, market problems, and concerns about residential development that was perceived as not paying its own way.  See Marlon G. Boarnet & Nicholas S. Compin, Transit-Oriented Devel­opment in San Diego County: The Incre­mental Implementation of a Planning Idea, 65 J. Am. Plan. Ass’n 80, 90-92 (1999).

[84] See Daniel R. Mandelker, Environmental Policy: The Next Generation, 64 Town Plan. Rev. 107, 108-09 (1993).

[85] See id.

[86] See id.

[87] It is not clear, of course, that urban growth bound­aries and development tiers are entirely responsible for the price effects that occur where these controls are used.  An answer to the cause-and-effect question is not important, howev­er, to landown­ers inside and outside the boundary.  Inside the growth bound­aries, higher land prices create pressure for intense develop­ment, and can create equity problems if higher prices mean that lower income households cannot find adequate housing.  It should also be pointed out that dramatic price differences on either side of the boundary are only different in degree from the price differentials that always occur in developing areas.   In the absence of a growth boundary, however, the price curve will slope gradually.  There will not be the dramatic fall-off that occurs at the boundary line.  See Tom Daniels, When City and Country Collide: Managing Growth in the Metropolitan Fringe 190 (1999); Keith W. Dearborn & Ann M. Gygi, Planner’s Panacea or Pandora’s Box: A Realistic Assessment of the Role of Urban Growth Areas in Achieving Growth Management Goals, 16 U. Puget Sound L. Rev. 975, 977-78 (1993).

[88] In Portland, the metropolitan district has defined the “urban reserve” as “land likely to be needed . . . for a 30 to 50 year period.”  Portland, Or. Metropolitan Code § 3.01.010 (1998), available at <http://www.multnomah.lib.or.us/metro/glance/metcode/ metcode1.html>.  However, under the rules that apply to the program, land closest to the urban growth boundary are likely to be considered first in any urban growth boundary amendment.

[89] See Golden v. Ramapo Planning Bd., 285 N.E.2d 291 (N.Y. 1972), appeal dismissed, 409 U.S. 1003 (1972). 

[90] See id. at 304-05.

[91] See First English Evangelical Lutheran Church v. Los Angel­es County, 482 U.S. 304, 318-19 (1987).  Language in First English suggests that a temporary moratorium on development might not be a taking.  See id. at 321 (noting that the Court did not have before it a “case of normal delays” in obtaining building permits, zoning changes, and the like). 

[92] See Lucas v. South Carolina Coastal Council, 505 U.S. 1003, 1014-19 (1992).

[93] See id.

[94] See id. at 1031 (“We emphasize that to win its case South Caro­lina must do more than proffer the legislature’s declaration that the uses Lucas desires are inconsistent with the public inter­est . . . .”).

[95] Similar issues arise when communities impose moratoria, either to provide an opportuni­ty to revise comprehensive plans and land use regulations, or to prohibit development until public facilities are adequate to serve the new development.  If the moratorium is a taking because it prohibits all development during the moratorium period, a court could award compensation for the time the moratori­um was in effect.  See Daniel R. Mandelker, Land Use Law § 6.11 (4th ed. 1997).

[96] If a landowner delays in bringing a takings claim, the delay may work against her because a court may hold that a self-imposed delay means a landowner does not have investment-backed expectations that were frustrated by the development restriction.  See Dodd v. Hood River County, 136 F.3d 1219, 1230 (9th Cir.); Tahoe-Sierra Preservation Council, Inc. v. Tahoe Reg’l Planning Agency, 34 F. Supp.2d 1226, 1240-41 (D. Nev. 1999) (appeal pending).  Courts consider invest­ment-backed expectations when they apply the Penn Central balanc­ing test to takings claims.  See Penn Cent. Transp. Co. v. New York City, 438 U.S. 104, 123-35 (1978) (providing three relevant factors to consider when examining a takings claim: (1) the economic impact of the regulation on the landowner, (2) the extent to which the regulation interferes with investment-backed expectations, and (3) the character of the governmental action).

        An exception to the Lucas per se taking rule may also bar landowners who bought land after the UGB was adopted from making takings claims.  Lucas held that property was subject to “back­ground principles” of state law.  See Lucas at 1029.  Although the Court did not explain what this term means, some courts have held that a landowner who buys land takes title subject to legislation adopted before she acquired title.  See, e.g., Gazza v. New York Dep’t of Envtl. Conservation, 679 N.E.2d 1035, 1040-42 (N.Y. 1997) (refusing to find a taking where a homeowner was denied a setback variance for wetland regulations known by him to be in existence prior to his purchase of the property); Hunziker v. State, 519 N.W.2d 367, 371 (Iowa 1994) (“[T]he ‘bundle of rights’ the plaintiffs acquired by their fee simple title did not include the right to use the land contrary to the provision of those three Iowa Code sections. . . .  These sections and their resulting prohibitions concerning the use of land ran—so to speak—with the land.”).

[97] See Lucas at 1019 n.8.

[98] See, e.g., Del Monte Dunes v. City of Monterey, 95 F.3d 1422, 1433 (9th Cir. 1996) (finding that since a sufficient number of people would buy the proper­ty for the restricted use it is “commercially marketable”), aff’d on other grounds, 119 S. Ct. 1624 (1999); Florida Rock Indus. v. United States, 18 F.3d 1560 (Fed. Cir. 1994) (finding that when determining fair market value a detailed inquiry into motivation and sophistication of buyers is not necessary).

[99] Controls explicitly adopted to defer develop­ment on a temporary basis are another possibility.  The well-known Ramapo case upheld a growth manage­ment program that delayed develop­ment for up to eighteen years, and authorized the approval of new develop­ment only when served by ade­quate public facili­ties and services.  See Golden v. Ramapo Planning Bd., 285 N.E.2d 291, 302 (N.Y. 1972), appeal dismissed, 409 U.S. 1003 (1972).  The town based its growth management plan on a compre­hensive plan, and the New York court relied on the plan in upholding these restric­tions on develop­ment.  See id.  Moratoria and other controls that delay development temporarily are now vulnerable under the Supreme Court’s recent takings cases as invalid temporary takings.  Some courts since First English have held that interim planning moratoria are not takings.  See, e.g., First English Evangelical Church v. County of Los Angeles, 258 Cal. Rptr. 893 (Cal. Ct. App. 1989) (holding that an interim ordinance was not a taking); Williams v. City of Central, 907 P.2d 701 (Colo. Ct. App. 1995) (holding that a gaming moratorium was not a taking absent extraordinary delay); Woodbury Place Partners v. City of Woodbury, 492 N.W.2d 258 (Minn. Ct. App. 1992) (holding that there was no taking in an adoption of a two-year moratorium).

        However, although a delay in developing land outside a UGB may be temporary, the restriction on land that prevents develop­ment is not adopted as a temporary restric­tion.  This fact may lead a court to hold, as it did in Tahoe-Sierra Preservation Council, 34 F. Supp. 2d at 1248-51, that the restriction is not the equivalent of a moratorium, and that a taking has occurred. 

[100] See Boundary Drive Assocs. v. Shrewsbury Township Bd. of Supervisors, 491 A.2d 86, 90 (Pa. 1985).  See also Agins v. City of Tiburon, 447 U.S. 255, 261 (1980) (refusing to find a compensable taking in California’s open-space plans).

[101] See Mandelker, supra note 95 , § 12.10.  See, e.g., Still v. Board of County Comm’rs, 600 P.2d 433 (Or. Ct. App. 1979) (upholding rejection of non-farm development that violates agricultural preservation policy in exclu­sive agricul­tural zone even if economically unfea­sible to farm land and no interference with farming in surround­ing area).

[102] For examples of excellent treatises on the law of takings, see generally R. Meltz et al., The Takings Issue (1999) and Ste­phen J. Eagle, Regulatory Takings (1996).

[103] The Court in Lucas clearly indicated that regulations denying a property owner all “‘economically viable use of his land’” are per se takings.  See Lucas v. South Carolina Coastal Council, 505 U.S. 1003, 1016-19 (1992) (quoting Agins, 447 U.S. at 260).

[104] See, e.g., K & K Constr., Inc. v. Department of Natu­ral Resources, 575 N.W.2d 531, 535-38 (Mich. 1998) (holding that for a permit application where there was a single comprehensive development comprised of several tracts in common ownership, the parcel under consideration included those tracts).

[105]  See, e.g., Bowles v. United States, 31 Fed. Cl. 37 (1994) (upholding a takings claim for denial of a permit for develop­ment of wetlands under the Clean Water Act, 33 U.S.C. §§ 1251-1387 (1994)).

[106]  Support can be found for this position in Justice Brennan’s opinion in Penn Central, although it was not fully devel­oped.  See generally Penn Cent. Transp. Co. v. New York City, 438 U.S. 104 (1978).  See also Daniel R. Mandelker, Waiving the Taking Clause: Con­flicting Sig­nals from the Supreme Court, in 1994 Proceedings of the Insti­tute on Plan­ning, Zoning, and Eminent Domain 57 (Southwestern Legal Foundation ed., 1995) (noting the convoluted nature of takings jurisprudence).

[107]  See Norbeck Village Joint Venture v. Montgomery County Council, 254 A.2d 700 (Md. 1969).  It should be noted that in this author’s opinion the Maryland courts are more receptive than most to local government land use regula­tions.

[108]  See id. at 703.

[109]  See id. at 703-04.

[110]  The court held that the land­owner “did not, by an Olney plan country mile, meet their heavy burden of showing that the rezon­ing they dispute confis­cates their property.”  Id. at 706.

[111]   See Security Management Corp. v. Baltimore County, 655 A.2d 1326, 1328 (Md. Ct. App.).  The court also rejected equal protec­tion and due process claims.  See id. at 1330-33.

[112]  See id. at 1329.

[113]  See id. at 1330.  The county council had rejected a rezoning to 16 dwell­ing units to the acre in what the developer called an “environ­men­tally sensi­tive” community. 

[114]  One commentator has suggested clustering tech­niques for developments in large lots that can leave room for future infill development when a UGB expands.  See Easley, supra note 13 , at 14.  How effective this technique can be is problematic.

[115]  The courts have upheld zoning for up to five-acre lots when necessary because of environmental conditions.  See Mandelker, supra note 95 , § 5.26.

[116]  See Julian Conrad Juergensmeyer et al., Transfer of Development Rights After Suitum, 30 Urb. Law. 44l, 444-48 (1998).

[117]  See id. at 444-46.

[118]  See Pruetz, supra note 24 , at 210-14.

[119]  See Barry C. Field & Jon M. Conrad, Economic Issues in Programs of Transferable Develop­ment Right, 51 Land Econ. 331, 338 (1975).

[120]  See Sarah J. Stevenson, Note, Banking on TDRs: The Government’s Role as Banker of Transferable Development Rights, 73 N.Y.U. L. Rev. 1329, 1371 (1998).

[121]  See Mandelker, supra note 95 , §§ 6.27-6.30.

[122]  I am indebted to Ed Sullivan for these suggestions.

[123]  There may be legal problems in levying impact fees in established neighbor­hoods if the municipality does not have the authority to levy these fees in connection with the issuance of a building permit or other development approval, such as a condi­tional use.  See, e.g., Bringle v. Board of Supervisors, 351 P.2d 765 (Cal. 1960) (holding that a zoning board had implied power to attach condi­tion requir­ing dedication of land).  The opportunity to levy fees as part of subdivi­sion approv­al does not usually exist because inner city areas are built-up.

[124]  The plan for King County in Seattle, Washington is an example.  See Douglas R. Porter, Profiles in Growth Management 230-55 (1996).

[125]  See Mandelker, supra note 95 , §§ 6.32-6.34.

[126]  Id.

[127]  See id. § 201.1(6)(a).

[128]  See, e.g., Dolan v. City of Tigard, 512 U.S. 374 (1994) (requiring that government’s permit condition does not impose more than a proportionate degree of burden on the landowner).

[129] See Porter, supra note 13, at 122-133.

[130] See S. Meck, Model Statutes on Uniform Development Standards, Concurrency and Smart Growth Technical Assistance (Apr. 19, 1999) (draft on file with author); Porter, supra note 13, at 131.  See e.g., Fla. Dept. of Transp., Report of Transportation and Land Use Study Committee 19-32 (1999) (on file with author).  The concurrency requirement, as stated in Florida legislation, is intended to provide “that public facilities and services needed to support development shall be available concur­rent with the impacts of such development.”  Fla. Stat. Ann. § 163.3177(10)(h) (West 1999).  In Florida, the concurrency re­quirement has tended to force new development to the urban fringe, where service levels are higher.  See Fla. Dept. of Transp., supra.

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Jill Yelverton 
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