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A Guide to Municipal Tree and Woodland Preservation Ordinances

Trees and woodlands enhance beauty, property values, health, and community appeal, but many areas lack policies to protect them during development.

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Updated:

March 19, 2025

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Why Ordinances Are Important

People appreciate trees and woodlands for their beauty and the beneficial ecosystem services they provide for the places they live and visit. Preserving trees during development can increase property values and municipal property tax revenues, improve community reputation and attractiveness, and enhance human health and quality of life. But, many municipalities in growing places lack policies to protect and preserve native and other trees from land conversion and development. Other municipalities realize they are trustees of a valuable resource that citizens can enjoy now and in the future.

What Are Ecosystem Services?

Trees and other parts of a forest, such as soils and wildlife, provide many benefits called ecosystem services. These include environmental, economic, social, and human health benefits. As an example, mature trees associated with homes can raise property values up to seven percent, and trees and woodlots can help lower stormwater levels.

Sentiment and Connection

In most cases, tree preservation ordinances are sparked by public outcry after trees are damaged or destroyed during land development. Efforts to preserve trees and woodlands have been motivated by peoples' genuine concern for trees, as well as foreboding about increased land development and loss of enjoyment and quality of life. People often feel deep emotional connections with trees they have long enjoyed, admired, and even loved and cherished. People may argue that protecting spiritual values is important in communities, and trees have come to symbolize the quality of life and sense of place they and their families enjoy. Tree preservation ordinances can support an environmental ethic within a community and help maintain a sense of place while land development and change occur.

Pennsylvania's Legal Foundation

Pennsylvania municipalities are provided authority to enact and enforce zoning and other ordinances guiding land development through the state constitution and state-enabling legislation such as the Pennsylvania Municipalities Planning Code and the Pennsylvania Township and Borough Codes. The basic power of government to protect public health, safety, and welfare is termed "police power." This power is the foundation for such municipal policies as zoning and subdivision and land development ordinances (SALDO). Zoning, SALDO, stormwater, and other ordinances can be used by municipalities to protect the health, safety, and welfare of people as a place develops and grows.

The Impact of Land Conversion and Development and Community Response

In Philadelphia, southcentral, northeast, and other growing regions of Pennsylvania, increasing population growth, land conversion and development, and urbanization have led to the widespread removal of trees and woodlands. This loss has triggered public outcry, especially when it occurs in properties undergoing subdivision and other land development. In some municipalities, the destruction of trees is considered to reduce ecosystem services and quality of life and formally interpreted as a threat to public health, safety, and welfare. Consequently, citizens working with elected officials have imparted effective political support for tree and woodland preservation and the incorporation of these resources into land development design. The success of many municipal tree and woodland preservation ordinances, especially ones affecting the development of private property, is likely due to considerable public support, proper preparation with the participation of landowners and developers, and excellent administration and enforcement.

Ordinance Costs and Benefits

Some municipalities have successfully enacted ordinances to protect and preserve trees in development. Their success is reflected in higher-quality developments, increased property value, and strong public support for the ordinance.

It is impossible to preserve trees and woodlands without providing adequate space for their health and growth. Retention and preservation of trees within a subdivision and other land development have promoted interesting and creative site designs. Landowners and engineers have developed more sensitive land development plans that are designed to consider individual site constraints while providing for development density. Plans incorporating trees into development design allow developers and homeowners to enjoy the economic values of tree preservation, such as increased home sales prices and development of equity.

Municipal tree preservation ordinances have costs such as permit appeal, conflict and opposing attitudes, additional costs of development, and costs of tree maintenance. Additional costs are imposed on land development in terms of tree assessment, design, engineering, and construction costs. Costs incurred by developers and others are most often passed on to the end user/purchaser. Accordingly, ordinances can have some inflationary effects on building and land prices. Costs have been mitigated by municipalities offering developers incentives such as increased development density and credits for stormwater management, landscaping, and landscape buffers. In addition to private sector costs, costs are placed on a municipality in terms of ordinance administration and enforcement.

Problems with Tree Preservation Ordinances

Some municipalities have experienced problems and concerns after ordinances have been enacted. These include ordinances restricting the maintenance of single-family and other residential yards. Conflicts between municipal departments and ordinances in the administration of the ordinance (e.g., required parking and set back requirements versus required space for tree preservation). Ordinances do not protect trees during demolition for infill and redevelopment. And, tree preservation ordinances are confused with timber harvest ordinances.

The purpose of tree preservation and timber harvest ordinances has been confused by some municipalities; they are distinct and different in purpose. Tree preservation ordinances protect trees and woodlots during land development. Timber harvest ordinances regulate timber harvest and other forestry operations with no land development involved. Tree replacement and other standards should not be taken from tree preservation ordinances and placed in timber harvest ordinances.

Objectives of a Tree and Woodland Preservation Ordinance

If a tree preservation ordinance is deemed appropriate for a municipality, the following objectives should be considered in its preparation.

The ordinance will be justified by the effect of tree and woodland removal on a community's health, safety, and welfare, not on aesthetic concerns alone.
The ordinance will affect private property as little as possible and provide subsidies and incentives for developers.
The ordinance regulates land development, not maintenance of residential yards.
The ordinance's intent will not be to preserve all trees on a parcel. It will preserve worthy, healthy trees and woodlands, providing ecosystem services, including historic and cultural values.
The development and enactment of an ordinance will have substantial public and political endorsement. The public, including landowners and developers, will be engaged in preparation.
An ordinance will be written and administered so that it is enforceable, given the abilities of the municipality. Adequate funding for ordinance administration and enforcement will be available.

Municipalities considering tree preservation or other ordinances should ask a few questions.

What are ordinance benefits and costs? Do benefits outweigh costs?
Will the ordinance be acceptable to public officials, citizens, developers, and other groups?
Does the ordinance achieve its purpose in a technical sense?
Are arboricultural and other technical standards correct?
Does the municipality have the commitment and capability to administer and enforce the ordinance?

Different Municipal Approaches to Tree Preservation Ordinances

Currently, Pennsylvania has 2,560 municipalities; each one is provided authority by the Pennsylvania Municipalities Planning Code to enact zoning and subdivision and land development ordinances (SALDO). With this type of locally orientated political structure, municipalities take different approaches to enacting tree preservation ordinances.

Article 5 (Subdivision and Land Development) and Article 6 (Zoning) of the Pennsylvania Municipalities Planning Code provide authority, standards, and procedures for using municipal ordinances to preserve trees and other natural resources during land development. Tree preservation ordinances have been enacted as zoning ordinances. Some are zoning ordinances that are also incorporated into subdivision and land development ordinances. And some have been incorporated only in sections of a municipality's subdivision and land development ordinance. Pennsylvania municipalities have also enacted tree preservation ordinances as "free standing" ordinances under provisions of the Pennsylvania Second Class Township Code and Boroughs Code. Interested people should seek advice from municipal planners and solicitors in the decision of where to place a tree preservation ordinance in a municipality's code of ordinances.

Summary Tree Preservation Ordinance Outline

Section 1. Purpose: Describes why the ordinance is being enacted and its effect on health, safety, and welfare.
Section 2. Definitions: Provides definitions of technical and legal terms in the ordinance.
Section 3. Administration and Applicability: Describes who will administer the ordinance and what type of land development, trees, and woodlots the ordinance applies to.
Section 4. Tree Preservation and Protection: Describes required permit application materials, including tree preservation and tree protection plans, and permit review process.
Section 5. Credits for Tree Preservation: Describes landscaping, buffer, and other credits provided for preserving trees and woodlots in a land development.
Section 6. Replacement Tree Requirements: Describes replacement requirements for removed trees.
Section 7. Violation and Enforcement: Describes violation of the ordinance and enforcement remedies.

Example Outline of a Municipal Tree and Woodlot Preservation Ordinance

An outline for a municipal tree and woodland preservation ordinance is provided below. In the outline, bulleted and italicized information provides examples of wording that has been taken from enacted municipal ordinances.

Section 1: Purpose

Protecting aesthetic benefits is not enough. Water quality, stormwater management, increased property value, climate, and human health should be incorporated as important ordinance purposes. The purpose of the ordinance should be clearly expressed, including protecting the health, safety, and welfare of people.

The purpose of these regulations is to encourage the protection of trees and woodlots through sound land use practices. Trees improve air and water quality, reduce soil erosion and stormwater, provide habitat for desirable wildlife, moderate climate, increase community image and property values, and protect the public health, safety, and welfare.
1. It is the intent of the Chapter to:
  1. Preserve, protect, and maintain existing township trees and to increase overall tree canopy and understory on both public and private lands.
  2. To preserve trees in good condition on site whenever possible by ensuring that all applications for grading permit, and subdivision and land development shall respect existing trees and as a natural resource.
  3. To preserve and protect all individual and groups of heritage trees as defined within.

Section 2: Definitions

To allow understanding and enforcement of the ordinance, technical and other terms are defined, such as heritage tree, tree protection zone, dripline, and tree risk.

Arboricultural Standard: Generally accepted industry standards for tree care practices.

Caliper: Diameter measurement of nursery stock. For 4-inch-diameter stock or smaller, the measure is taken at 6 inches above the root ball. For stock above 4 inches, the measurement is taken at 12 inches above the root ball.

DBH: Diameter at breast height is a measure of trunk diameter in inches taken 4½ feet above the natural grade line. The measured section of the tree trunk should be free of branches and representative of the typical form of the tree. DBH is applied to existing trees, and caliper is used for nursery stock.

Encroachment: Intrusion into a tree protection zone by root or canopy pruning, grading, or other development activity.

Hazard Tree: A tree with uncorrectable defects severe enough to pose a present danger to people, buildings, or property under normal growing conditions.

Heritage Tree: Any tree over 40 inches in DBH or considered worthy of preservation because of species, size, rarity, or historical value. They can be individuals or groves and can be on private or public property.

Horticultural Report: A report that provides information on tree(s) condition (health and structure), tree risk, and the worthiness of a tree(s) for preservation.

Invasive Species: Any tree or plant that appears in the most recent invasive species list published by the Pennsylvania Department of Conservation and Natural Resources.

Land Development: A subdivision of land and/or providing improvements to lots, including streets, sanitary sewer, storm sewer, water main, or other improvements.

Native Tree: A tree species indigenous to the northeastern United States that occurs naturally in a particular region, state, ecosystem, or habitat without direct or indirect human actions.

Replacement Tree: A tree required to be planted per this chapter to compensate for the removal or damage of existing trees on a parcel.

Shade Tree Commission: A local municipal commission enacted by ordinance and responsible for tree-related matters in the municipality.

Tree: Any hardwood perennial plant, whether evergreen or deciduous, or a species that normally reaches a height of eight feet or more at maturity.

Tree Preservation Plan: Plan for a parcel proposed to be developed that identifies the size, species, and location of any heritage tree and/or any tree or trees 6 inches or greater in diameter breast height. This plan must denote each tree, or group of trees, to be saved, removed, or pruned, or the tree protection zone encroached upon a parcel proposed to be developed.

Tree Protection Plan: A plan that provides information on the arboricultural standards used to protect trees during construction. This could include fencing and canopy and root pruning being completed using proper arboricultural standards under the supervision of a qualified arborist, and other tree treatments.

Tree Protection Zone: An area approved by an arborist that is radial in all directions to the trunk of a tree, or grove of trees, to be protected where grading, pruning, and other disturbances shall not be completed without a permit.

Section 3: Ordinance Administration and Applicability

Section 3: A) Defines who will administer the ordinance.

The Township Planning Director, or their designee, shall be responsible for administration of all provisions of the Township Tree Preservation and Protection Ordinance.

Section 3: B) Defines what the ordinance applies to and what permit application initiates the ordinance (earth disturbance, grading, demolition, building, SALDO, zoning).

Unless exempt, any property owner or developer who makes application for an earth disturbance permit, grading permit, demolition permit, building permit, subdivision, land development, or zoning change application shall comply with the terms of this chapter.

Section 3: C) Defines what the ordinance is not intended to apply to (e.g., forestry and horticultural activities, residential property maintenance, earth disturbance on residential property less than 5,000 square feet).

Except as to heritage trees, this chapter is not intended to apply to:
1. The removal of trees from a lot containing an existing single-family residence, unless such removal is a part of grading activities that affect 5,000 square foot or more of area. However, no property owner or occupant shall be permitted to remove or damage trees if such trees have been planted or preserved to meet the requirements of Township ordinances or an application approved by the Township. Property owners must receive the approval of the Township Supervisors to remove heritage trees as defined in this ordinance.
2. The removal of trees identified as dead or diseased by the Township Shade Tree Commission.
3. The removal of trees for sale in the ordinary course of business from horticultural properties, such as farms, nurseries, or orchards.
4. The removal of any tree that has become or threatens to become a danger to life or property.
5. Forestry practices, in following established best management practices for harvest and sustained yield forestry.

Section 3: D) Defines size, species, and historical significance of trees to be protected during land development and/or percent of canopy cover to be protected.

All trees 6" DBH or greater will be placed on the land development plan and no more than 25% will be removed.
All native oaks 4" DBH or greater shall be placed on the land development plan
All trees 6" DBH or greater will be placed on the land development plan and no more than 25% will be removed.
All native oaks 4" DBH or greater shall be placed on the land development plan and shall not be removed or encroached upon without a permit approved by the planning department.
Heritage trees and groves as defined in the definition section shall not be removed on private or public property without the approval of the township supervisors.
The percentage of canopy allowed to be removed or protected on developable property is described in this section and can vary (15% - 40% preserved) for different zoning districts and types of development.
Every application for a grading permit and subdivision and land development application shall preserve 20% of the existing tree canopy on the lot, except where it is demonstrated that it is not practical to do so and approved by the Township Arborist. The factors for determining the practicality of tree preservation on a given parcel shall be as follows:
1. Tree condition- Trees with poor health and structure.
2. Tree species- Invasive or inferior tree species.
The removal of more than 50% of the trees on any lot shall not be permitted under any circumstance unless expressly permitted by the terms of this ordinance.

No heritage tree is to be removed for any reason on public or private property without the approval of the Township Supervisors after recommendation from the Shade Tree Commission. Any heritage tree removed without the approval of the township supervisors shall be a violation of this ordinance.

Section 4: Permits and Tree Preservation and Protection Plans

This section defines required permit application material for tree removal, tree pruning, or encroachment into tree preservation zones. It defines the permit review and approval process. In addition, requirements for tree preservation and tree protection plans are provided, including engineering, architectural, and arboricultural standards for tree protection.

Section 4: A) Describes required permit application materials. Common permit application includes a tree preservation and protection plan as described below in Section 4-B. Permit review and approval processes are described, including those that review tree preservation and protection plans and permit applications for tree removal, pruning, or encroachment of trees. Municipal tree commissions, environmental advisory councils, planning commissions, township arborists, and township engineers have all been involved in permit review and approval.

Trees shall not be removed on the parcel without an approved permit. Grade changes and excavations shall not encroach into a tree protection zone without an approved permit. Root or canopy pruning of protected trees shall not take place without an approved permit.

Section 4: B) Describes the content of a Tree Preservation Plan (explained in the definition section of this publication) for a parcel proposed for development. Preservation plans identify the size, species, and location of any heritage tree and/or any tree or trees of a certain size (e.g., 5 inches or greater in diameter). This plan denotes each tree, or group of trees, to be saved, removed, pruned, or encroached upon on a parcel proposed to be developed. The plan is used to design the development while preserving trees and tree canopy.

Applications for an earth disturbance permit, grading permit, demolition permit, building permit, subdivision and land development permit, or zoning permit shall include a tree preservation plan except any development that does not include ground coverage disturbance. The tree preservation plan shall denote each tree, or contiguous grove of trees, to be preserved, removed, pruned, or have a tree protection zone encroached upon by pruning, grading, or other development activity.
The tree preservation plan shall note the species and condition of individual trees over five inches in diameter. It shall also contain the trunk and canopy dripline location of all trees over five inches DBH and existing and proposed topographic information at two-foot contour intervals and shall show all existing and proposed buildings and structures, driveways and parking areas, drainage structures, stormwater detention/retention areas, utilities, construction staging areas, and all limits of grading. If two or more trees are in a contiguous grove, the outer edge or edges of the grove's canopy shall be marked on the tree preservation plan.
The tree preservation plan for a proposed development shall be reviewed by the Shade Tree Commission at a public hearing.

Section 4: C) Describes a Tree Protection Plan (explained in the definition section of this publication) for a parcel proposed for development. A Tree Protection Plan provides standards to protect trees during the development of a parcel. They can be very extensive and include pre- and post-construction conferences, protective fencing requirements, standards for branch and root pruning and other arboricultural standards, engineering standards for root preservation, and more.

Prior to any work on the parcel a forty-eight-inch-high snow fence, or other suitable fence approved by the Township Arborist, mounted on steel posts located five feet on center, shall be placed along the boundary of each tree protection zone or area. Any damage to the fencing or encroachment on a tree's protective zone shall be remedied immediately. Any observed damage to a protected tree shall be reported to the Township Arborist immediately.
Upon approval for any permit subject to this ordinance, and prior to any construction, demolition, or earth disturbance on the site, a pre-construction conference shall be held on the site between the Arborist and the applicant. The Township Arborist shall inspect and approve the tree protection fencing and other devices that have been installed to protect trees before work begins.
Upon approval of tree protection measures by the Township Arborist, demolition, grading, and construction may proceed, provided all pertinent permits have been secured.
All permitted arboricultural work, including canopy and root pruning, shall be completed using proper arboricultural standards approved by the Township Arborist and supervised by an International Society of Arboriculture Certified Arborist.
To facilitate preservation and protection, retaining walls, porous paving and pavers, and other engineering devices approved by the Arborist may be permitted to be used within a tree protection zone.
Post-Construction Conference
1. Before an occupancy permit is issued, the Township Arborist will inspect and approve the planting of all replacement trees required by any permit approved by the Commission with advice from the Arborist. The Township Arborist will also inspect the condition of all preserved trees. Any trees damaged by construction activities may be replaced at the recommendation of the Township Arborist.

Section 5: Credits for Tree Preservation

Landscape buffer and/or parking lot landscape credits can be provided for tree preservation dependent on preserved tree diameters or percentage of tree canopy. Other credits may be considered, including parking and stormwater management requirements. Increased, but clustered, development density has been used as an incentive.

Landscape buffers as defined in the Township Zoning Ordinance or other ordinances shall, whenever possible, be met by preserving existing trees. The number of trees required to be planted in a landscape buffer may be reduced by a credit for preserved trees as defined below.
Preserved trees around the perimeter of the property may offset landscape buffer requirements for a site. Any tree within 20 feet of any proposed building or within five feet of a proposed road or sidewalk shall not be considered a preserved tree for this calculation.

DBH of Preserved Tree Number of Planted Trees Credited

30 inches or greater 8

18 to 29 inches 6

12 to 17 inches 4

6 to 11 inches 2
Preserved trees along the perimeter of parking lots and buildings may replace or credit landscaping requirements for a development as defined in the Township Zoning Ordinance or other ordinances.

Section 6: Replacement Tree Requirements

Replacement tree requirements describe the number of replacement trees required, species, percent native, size, and maintenance of replacement trees. The use of in-lieu fees for tree replacement has been challenged in court by developers and landowners, and past county court decisions have found that tree replacement must be associated with the parcel being developed. If, with the advice of a solicitor, it is determined that in-lieu fees can be used, the ordinance should contain how they are calculated, what fee will be charged, and where and how the fees can be used.

Every tree determined to be living and healthy which is designated to be removed shall be replaced with one or more new shade trees of a type approved by the Township with a trunk caliper of not less than three inches. The total caliper of replacement trees, measured at six inches above the ground line, shall equal or exceed the DBH of the tree(s) removed.
No heritage tree is to be removed for any reason without the prior approval of the Board of Supervisors after recommendation by the Shade Tree Commission. Any heritage tree removed without approval by the Board of Supervisors shall be replaced with tree of equivalent value as recommended by the Shade Tree Commission and approved by the Board of Supervisors.
The species of replacement trees shall be subject to the prior approval of the Shade Tree Commission. The species of replacement trees are to be hardy to the area, noninvasive, and 60% shall be native.
Replacement guarantee. All replacement plantings shall be guaranteed and maintained in a healthy condition, including deer protection as required, for at least 18 months or shall be replaced.

If there is not sufficient area on the developed lot and replacement trees cannot be planted off the development parcel, or if they are considered in an in-lieu account, standards for substituting larger trees or other vegetation on the development parcel can be provided.

If the Shade Tree Commission with advice from the Arborist determine that there is not sufficient area on a lot for proper placement and planting of all replacement trees, a percentage of the replacement trees that can be planted on a development site will be increased in caliper size from the two-inch minimum in accordance with the schedule found below.

Percent of Number of Trees that Cannot be Planted	Percent of Replacement Trees three-Inch Caliper	Percent of Replacement Trees four-inch Caliper	Percentage of Replacement Trees five-inch or greater caliper
1 to 10	10%	0%	0%
11 to 50	10%	10%	10%
51 to 100	30%	20%	10%
Greater than 100	40%	25%	25%

Subject to prior approval by the Tree Commission with advice from the Township Arborist, a maximum of 20% of the replacement trees may be replaced as shrubs with a minimum size of 24 inches in height at a ratio of six shrubs per required two-inch-caliper replacement tree. This substitution of shrubs only pertains when there is not sufficient area on the parcel for replacement trees.
Subject to the prior approval of the Tree Commission with advice from the Township Arborist, a maximum of 10% of the replacement trees may be replaced as groundcover at a ratio of 40 plants to one two-inch-caliper replacement tree. The minimum size of the groundcover is a one-gallon container. This substitution of groundcover only pertains when there is not sufficient area on parcel for replacement trees.

Section 7: Violation and Enforcement

Municipal ordinance enforcement in Pennsylvania lacks clarity at times because they can be enforced civilly or criminally, depending on what is in the ordinance text and the governing state statute that the ordinance is based on (e.g., Municipalities Planning Code or Second Class Township Code). The Pennsylvania Municipalities Planning Code (MPC) is the state-enabling legislation that authorizes most Pennsylvania municipalities to enact planning agencies and comprehensive plans and zoning and subdivision and land development ordinances. The MPC Section 515. Penalties, including Section 515.1. Preventive Remedies and Section 515.3. Enforcement Remedies describes enforcement and penalties for violating a municipal subdivision and land development ordinance, including provisions for tree preservation during land development. Section 616. Enforcement of the Code describes enforcement and penalties for violating a municipal zoning ordinance providing provisions for tree preservation during land development. Although examples are provided below, review MPC sections and contact a municipal solicitor for exact ordinance violation and enforcement wording.

Any person, firm, or corporation who shall violate any provision of this chapter, upon a determination of liability in a civil enforcement action brought before a magisterial district judge, shall pay a civil penalty of not more than $600 per violation, plus court costs, plus all attorneys' fees incurred by the Township for enforcing this chapter. Each day that a violation of this chapter continues and each section of this part which shall be found to have been violated shall constitute a separate offense.

Pennsylvania municipalities have enacted tree preservation ordinances and ordinances protecting heritage trees as "free standing" ordinances that consider violations as a non-traffic summary offense. Section 66601 of the Second Class Township Code authorizes a township board of supervisors to adopt ordinances in which the general or specific powers of the township may be exercised. Some Pennsylvania solicitors think that this includes preserving trees during land development. Section 3301.1 of the borough code authorizes the borough council to adopt ordinances to benefit the borough. Some solicitors think that this could include the authority to adopt a "free standing" tree preservation ordinance if the council or supervisors believe such an ordinance would benefit the borough. Although examples are provided below, contact a municipal solicitor for ordinance violation and enforcement wording.

The penalties for any violation of this chapter, including without limitation, failure to comply with a plan approved by the Tree Commission, shall be guilty of a summary offense and upon conviction therefore shall be subject to the enforcement remedies within the Township Code and any other applicable law.
Any person who violates this chapter, including property owners, occupants, tree companies, and gardeners, may be held liable for a violation of this chapter. If a violation occurs during construction, the Township may issue a stop-work order suspending and prohibiting further activity on the property until a mitigation plan, including protection measures for remaining trees on the property, has been approved by the Shade Tree Commission.

Conclusion

Trees and woodlots provide many benefits, including historical, cultural, environmental, recreational, economic, and human health-related advantages. These benefits enhance the quality of life for residents and their communities. As areas are developed, both citizens and municipal officials have acknowledged the value of trees and woodlots and the detrimental effects caused by their removal and damage. Growing concerns about stormwater management, water quality, and climate change may drive municipalities to enact tree and woodlot protection ordinances. These ordinances can balance land development and protecting an important community resource.

Further Information

City of Thousand Oaks California. 1987. City of Thousand Oaks Tree Preservation Ordinance: Article 42. Oak Tree Preservation. Note: One of the first tree preservation ordinances in California.
Commonwealth of Pennsylvania. Act 247 of 1968 as amended. Pennsylvania Municipalities Planning Code. Note: State-enabling legislation that authorizes municipal land use planning and regulatory policy in Pennsylvania.
Duerksen, C. et al. 2006. Practice Tree Preservation. American Planning Association.
Elmendorf, W. 1991. Oak Tree Preservation in Thousand Oaks California. Pp. 262-266 in Richard Standiford (ed.) Proceedings of the Symposium on Oak Woodlands and Hardwood Rance Management. USDA Forest Service.
Templeton, N. and D. Rose. 2012. The Role of Tree Preservation Ordinances in Green Infrastructure. American Planning Association.
USDA Forest Service. Changing Landscapes.