A Guide To Developing A Community Tree Preservation Ordinance
This guide was written by the Community Tree Preservation Task Force of the
Minnesota Shade Tree Advisory Committee (MnSTAC). The mission of the Task Force
is to preserve existing trees during development and to reforest land through:
|supporting the partnerships of builders, developers, foresters and communities;|
|guiding communities in developing their own tree preservation program.|
This publication was funded in part by a grant from the USDA Forest Service
Urban Forestry Center for the Midwestern States, North Central Forest Experiment
Station, Chicago, Illinois.
The Value of Trees
Trees have a great deal of financial value, from increased
property values to various environmental benefits. Trees
stabilize the soil and control water pollution, yield advantageous microclimatic
effects which conserve energy, preserve and foster air quality by removing
carbon dioxide (C02) and airborne pollutants, abate visual and noise pollution,
and provide a natural habitat for wildlife. They also provide welcome shade to
people and add color and interest to the urban landscape. Trees provide a
psychological boost to urbanites. People are generally more satisfied with their
neighborhoods if there are trees. Workers are more productive and hospital
patients recover faster if they can see trees outside their windows. The
benefits of established trees in our communities are subtle and often
The Magnitude of the Problem
Communities have long recognized the importance of trees.
Tree and woodland preservation is an emerging environmental issue as communities
also address concerns involving wetlands, flood plains, storm water, water
quality, steep slopes, and air quality. New construction too often leads to tree
loss and remaining trees lose vigor because of damage sustained during
construction. Communities can mitigate both tree loss and tree damage with well
conceived tree preservation ordinances or policies.
The Purpose of This Guide
This guide outlines a process by which each community can
develop a tree preservation ordinance consistent with their own particular goals
and needs. Communities are encouraged to educate and involve all of the
potentially interested or affected parties in this process. Also, important
elements of a successful ordinance are discussed. A listing of additional
available resources is also included.
The first step in defining the goals of the ordinance is to
obtain an inventory of the current situation. The
initial resource assessment could include information regarding:
|identification and location of the types of vegetation (i.e., cover types) which occur in the community;|
|identification of any unique ecosystems; |
|location of particularly large and/or historic trees; |
|profiles of the existing trees including species and size distributions.|
The initial evaluation should note areas of priority for
preservation such as wooded 100 year floodplains, wooded stream corridors,
wooded slopes, buffer zones, and aesthetically or environmentally fragile areas.
A map of these areas can lead to comprehensive planning and identify potential
areas likely to be adversely affected by development activities. Knowing all of
these factors can help establish the emphasis of the ordinance.
A community must first assess their tree resources before any constructive
ordinance decisions can be made. Each
community's ordinance must reflect the unique assets of its own urban forest.
Once the current resources have been identified, informed and attainable goals
for protection can be established. This process can create an effective and
usable tree preservation ordinance.
Goals and Scope of a Community
Tree Preservation Ordinance or Policy
Each community must determine its own needs and goals, and design its
ordinance to best achieve these objectives.
The goals of tree preservation ordinances can include:
|reducing tree loss during development; |
|reducing damage to standing trees during construction; |
|providing for replacement of trees lost during construction; |
|providing for planting trees where none occurred previously; |
|providing for the maintenance of preserved trees after construction is
The scope of the ordinance (or policy) may cover only projects undertaken by
the city on public land or it could also include work by utility companies,
private residential, commercial or industrial projects. There may be a minimum
size for a project to be regulated, measured in land area or in project cost.
The ordinance may regulate only tree preservation or may also include
replacement and new planting. It may or may not include provisions for education
or enforcement. Determining the goals and scope will be an important part of
developing the ordinance.
Drafting an Ordinance
The process by which the ordinance is developed is as
important as the actual language. An
ordinance should create a mechanism for the exchange of information. Therefore,
the relationships formed during the ordinance development process are crucial to
its potential success.
An ordinance marks the creation of a new
"organization", composed of people brought together from different
professions, positions and interests for the purpose of tree protection. This
creation of a working organization takes time for meetings, discussions, and
phone conversations. The process must build trust amongst the various parties.
The challenge of an ordinance is not getting it passed, but
getting people to follow its provisions. The best ordinances come about
- the ordinance provides for effective communication;
affected has a role in developing the ordinance, starting with the basic
- the objectives are simple and easy to communicate.
Importance of Education
The most important element of a successful tree preservation program is
education. The exchange of practical
information, unique concerns, and specific issues can lead to a better
understanding among those involved in drafting the ordinance.
Education should begin before an ordinance has been
drafted and should address the economic constraints of tree preservation and the
physical constraints of constructing on wooded lots. Unrealistic ordinances
prohibit development and construction in wooded areas, which may not be the goal
of the community.
Education should be offered to the following persons:
|City Advisory Commissions|
Home/property owners must understand the importance of their
active involvement during the construction process. They should also have a
basic knowledge of proper tree care to successfully maintain the trees which
remain on their lot. Construction workers must understand the goals of a tree
preservation program and the importance of preserving a tree's root system.
Education can take many forms including:
|Workshops with Community Leaders and Advisory Groups|
|Staff Training Sessions|
|Mailing to Interested/involved Parties|
|Recognize Contractors Who Excel at Tree Preservation (e.g., Builders
Association of Minnesota, Awards of Environmental Merit, etc.)|
|Historic Trees Brochures/Big Tree Contests|
Typical Ordinance Elements
The scope of the ordinance (or policy) will set the tone and
determine how much regulation a local authority desires to assert over the
protection and/or preservation of its forest resource, and the extent of the
educational efforts directed towards the public.
Tree preservation ordinances have been developed locally and
nationally to protect and preserve trees on private and public property. They
are usually developed to coincide with zoning or property subdivision
regulations. They can be very simple or complex in their scope. A simple
ordinance may stipulate that the cutting of any tree larger than a certain
diameter can be done only by permit and must be within a designated construction
area. A complex ordinance on the other hand may include formulas to determine
percentage of tree loss and the mitigation of the trees lost during construction
with a specified number of newly planted trees.
In most cases, tree preservation ordinances have been upheld
in the courts as reasonable extensions of a local government's zoning authority.
However, this authority needs to be consistent with that given to the local
governmental body through state statute. Once this is determined, the ordinance
should clearly state its purpose or goals. This will help with the
implementation, enforcement, and defense if the ordinance is challenged.
Any terms or common phrases that have special meaning within
the body of the ordinance should be listed and defined. By using standard
defined words the likelihood of misunderstanding or confusion when reading or
enforcing the ordinance will be reduced. Be specific in defining terms such as a
"significant tree" (including "type",
"species", "size"), "tree loss" and
"construction damage" and/or "grading damage". Sometimes
after writing the ordinance, it will be necessary to add >or
revise a definition to assist with its
Plan Review Process
The ordinance should explain the process of how a
new/proposed development will be reviewed. This section should walk the
prospective developer through the review of the project and detail the
information to be submitted with a request for rezoning, platting or permit.
Elements that may be required in the review process include
an inventory or survey of the existing trees (including species
and size) on
the site, (also, an accurate footprint of the proposed building on the site
should be provided by the developer), an estimate of the proposed tree removals,
an explanation of the tree protection techniques to be used such as protective
fencing, informational/warning signage, proper equipment and material storage
areas, and pre- and postconstruction care of the remaining trees. If replanting
is required, the developer may also need to submit a landscaping plan for
It is critical that the ordinance specify the minimal tree
protection methods that would be acceptable. Also, a professional forester,
certified arborist or landscape architect familiar with tree preservation issues
and techniques should have the authority to review the site and development
plans prior to their approval and any construction performed.
The heart of the ordinance should be the preservation of
trees in a woodland development. There are many variations to the intent of tree
preservation, but the bottom line becomes what you want to preserve, "the
forest or the trees" or "what aspects of the forest or the trees that
you want to preserve"? This often becomes an issue of just how many trees
make up a woodland.
Some ordinances will list a percentage of trees lost versus
the total trees remaining in the form of a tolerance barometer, i.e., if more
than 35% of the trees are removed by a development, this would be unacceptable
and a new plan would have to be submitted for approval.
Another approach is to specify that the forest left following development
will be similar to the one existing before the project was completed, i.e., if
15% of the trees on the site were larger than 24 inches, then trees this size
should make up 15% of the trees remaining after construction. The intent of this
provision is to have a woodland of similar size distribution after development,
thereby preserving the character of the woods.
Tree replacement is a simple concept, but to be equitable it
can become a very complex procedure. For example, an ordinance may require that
the loss of a 30-inch diameter tree must be replaced with the planting of
fifteen 2-inch diameter trees. However, not only is it difficult, if not
impossible (at times) to find enough suitable planting locations for the
replacement trees, this approach fails to mitigate the environmental effect of
mature tree loss.
A variety of replacement strategies are possible including:
|requiring developers to set aside wooded areas as preserves; |
|sliding scales; |
|percentage replacement; |
|off-site reforestation; |
|flexible no-net loss formulas.|
Each approach has its advantages and disadvantages-none is
perfect. When replacement of trees is included in an ordinance, the questions,
"why, how much, and where?" need to be primary considerations. The
intent of a tree preservation ordinance should be to provide incentives for
unique and creative project designs that complement the woodlands and replace
excessive tree loss.
The uniform and unbiased implementation of any ordinance can fail if some
precautions are not observed. Those who are charged with implementation must be
able to do so without bias or prejudice (avoiding politics). The ordinance
should be easy to read and understand for everyone, including the developer, the
staff, the elected officials, and the citizens of the community, or frustration
and mistrust may develop.
Developing an ordinance which creates incentives is a
positive way to achieve compliance. Examples include the preserved trees being
credited to the landscaping typically required on a project. Also, a protected
woodlot may be dedicated to the community in lieu of park dedication
Most ordinances contain provisions for enforcement and
penalties for violations should they occur during the construction process.
Enforcement usually involves an inspection process, and, when violations occur,
the developer may be held accountable by one of several methods:
|withholding of occupancy permits until the problem is
|loss of money in the form of a bond that was posted
prior to the start of construction;|
|stoppage of the project if violations are extreme.|
Some developers have been taken to court, losing their case
and required to reimburse thousands of dollars related to the tree loss. Some
ordinances require the violator to make reparations to the community by donating
trees to be planted on public property.
In some instances, an ordinance will cover the loss of trees through bonding
for several years to protect against tree loss due to construction injury. These
ordinances usually have a decreasing bond clause which reduces the amount of
money each year upon determination of the health and condition of the trees
impacted by the construction.
Trees and woodlands are valuable elements in any community's
infrastructure. Development in a community from the construction of a single
building to the improvements found in a new residential subdivision can have
adverse and permanent impacts upon this important natural resource.
Each community must decide upon its own appropriate balance of trees and
development. Both are important. The creation of a tree preservation ordinance
can assist in determining what an appropriate balance is for the community. When
all of the affected parties from property owners to developers/builders to city
officials are involved in making these decisions, and ultimately, creating the
tree preservation ordinance, the community inevitably improves the quality of
life for its residents without sacrificing economic progress.
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Building With Trees". Tree City USA Bulletin #20. The National Arbor Day
Foundation. Nebraska City, Nebraska.
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Nebraska City, Nebraska.
Hoefer, P. J., E. B. Himelick and D. F. DeVoto. 1990. Municipal
Tree Manual. International Society of Arboriculture. Urbana, Illinois.
International Society of Arboriculture. 1989. "Effects
of Construction Damage on Wooded Lots" (Video), and "Avoidance of
Construction Damage to Trees on Wooded Lots (Video). Urbana, Illinois.
Miller, N. L., D. M. Rathke, and G. R. Johnson. 1993.
"Protecting Trees from Construction Damage-A Homeowner's Guide".
University of Minnesota Extension Service Publication NR-FO-6135-S. St. Paul,
Stiegler, J. E., ed. 1990. "Community Tree Preservation: $$$ and Sense
for Our Community Trees". Proceedings of the 11th Annual Fall Conference,
Minnesota Society of Arboriculture, Chapter ISA. Duluth, Minnesota.
Department of Natural Resources
Division of Forestry
500 Lafayette Road
St. Paul, Minnesota 55155-4044
612-296-6157 or 1-800-766-6000
Copyright 1995, State of Minnesota, Department of Natural Resources.
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