"Zoning For Trees"

Prof. Buck Abbey, ASLA, CELA

Louisiana State University, Baton Rouge, Louisiana

Zoning and Building Codes

Planners and zoning commissions have a great responsibility for preserving trees in the city.

Zoning ordinances and building codes are the two principle tools for building communities. Architects, engineers and interior designers have designed with life safety codes for many years. Landscape Architects have not. The building codes set forth design standards, commonly accepted construction practices and agency requirements that must be met for all types of construction. The ‘building’ in building codes makes reference to the practice of building or construction and not just habitable structures referred to by laymen as ‘buildings.’ Therefore building codes are about sound efficient construction and not various types of buildings used to house society. Standard building codes, where most life safety issues are found, do not pertain to site development, land clearing, tree preservation, water conservation, site storm water management or landscaping construction. This is largely the reason that landscape architects have not been designing to code until recently. Building codes do not provide regulations for sensitive site development or redevelopment. Landscape and tree codes do that.

Building codes are closely related to community zoning laws and are often found within the same set of municipal ordinances but they are not the same. Zoning, as every planner will attest is more about how buildings are sited, how land use is allocated and how public health is maintained.. Building codes and zoning result in the built city as we see it today. Except for trees, vegetation and the natural elements of a building site or community.

What about the natural elements of a building site? Where are regulations found that protect and preserve trees and other sensitive site features? The answer of course is within community landscape and tree regulations? In the last four decades these ordinances are finding their way into community zoning laws primarily because the building codes do not understand them or accept them. Therefore planners, planning and zoning officials and design consultants must be knowledgeable about ‘green laws’ that protect, preserve and rebuild nature in the city. Zoning is the tool to keep nature in the city.

Designers are required to see that construction plans are in compliance with standard building codes and contractors must build accordingly. Planners must see that construction plans are in compliance with all zoning requirements including requirements for tree preservation, tree protection, tree planting, landscaping and the design of vegetative plantings on zoned building sites.

Only since the 1970’s have landscape regulations come into existence in communities across the nation as a method of making up for the oversight of nature in the standard building code. Landscape codes contained within municipal zoning ordinances regulate site development though the police power of zoning.

Trees are becoming an important aspect of zoning and planners need to understand how trees are an additional site zoning concern that complements setback, bulk, height and land use. Planners need to know how to properly craft zoning regulations to maintain nature in the city.

Nature In The City

Trees in the city are nature’s great symbol of community health. A green community is a clean community.

A community with trees is a healthy community. The World Health Organization lists eleven characteristics of a healthy community. One of their characteristics of a healthy community is an ecosystem that is stable in the present and sustainable in the long run and will lead to a clean, safe physical environment of high quality. Treed communities are healthy when natural systems are present and functioning. The literature suggests that nature in the city will enhance biodiversity, reduce atmospheric carbon, improve water quality, filter the air and reduce toxic chemicals in the environment. A community that is zoned for tress will allow vegetation to clean the air, cool the climate and purify the water. Healthy communities are beautiful, supportive of wildlife and environmentally efficient. That is the energy of the sun and its ability to generate biomass is in equilibrium with forces of nature or mankind that work to destroy nature. Sustainability is the measure of a healthy city and trees do their part in keeping a community healthy. A city without trees is not as healthy primarily because the actions of mankind to develop urban land remove or alter the natural systems that sustain life. Air purity may be the best example to understand. Trees absorb carbon, urban pollution and other trace elements that are essentially harmful to human health and animal and crop production while at the same time producing oxygen, atmospheric humidity and shade through the process of photosynthesis, absorption and evapotranpiration that are essential biological functions of trees. Everyone would agree that a village is healthier than a town, a town is healthier than a city and a city if be far a more healthy place than a mega-city. The more paved a city becomes; the less opportunity there is for nature’s systems of soils, water, atmosphere, vegetation, animal life and climate to work for mankind. And as a bonus, a healthy city is tranquil, relaxing and refreshing to the human spirit by simply adding beauty to the surroundings.

Zoning is the tool created to ensure community health and to allow for more livable places. Trees bestow upon towns and cities social, environmental and economic benefits that make the community a fit place to live. Trees and other vegetation filter pollutants from air, provide shade for homes, buildings and parking lots and cleans contaminates from storm water. Trees and preserved habitats within a community such as a forested wetlands or stream bank buffers can detain storm water runoff, reduce flooding and abate the erosion of productive nutrient rich soils. Maintained woodlands within cities provide habitat for animals and create desirable living and working places for citizens. Plantings increase property value, attract shoppers to businesses and provide relief from summer sun and tropical storms. The simple act of planting a tree will decrease cooling costs for any building and the cost savings will far outweigh the original cost of the planting. Trees provide many benefits useful to society other than beauty.

But perhaps the most important thing that happens when communities preserve there natural forests, meadows, wetlands, streams, marshes, bogs and trees, is that citizens of the community have a greater ecological consciousness. With a better understanding of the importance of nature in the city, urban dwellers will do their part to keep the city clean and healthy.

Communities who manage their urban forests and preserve nature in the city do so through zoning. To keep a city healthy, it must be zoned to preserve trees and other vegetation and maintain an appropriate percentage of undeveloped land in which nature is allowed to fully function. Zoning of sensitive lands, lands containing many trees, is something that cities should do, and have the authority to do.

Planning commissioners and professional planners ensure that nature in the city is cared for by enacting comprehensive landscape codes that specifies minimum standards for the preservation of nature in the city. This is done especially in regard to trees and other landscape plants which are nature’s most visible symbol within the city. To maintain trees in a community it is important to have site development regulations that control or encourage land clearing, habitat preservation, tree protection, water conservation and on-site storm water management. In recent years, city after city across the nation have turned to this type or local regulatory action as a means of ensuring better site design and acceptable community design standards.

To preserve nature in the city tree regulations must be contained within a community’s zoning ordinance. Therefore, zoning for trees can be seen as basic zoning criterion. Zoning for trees and places on building sites in which they may grow can complement the traditional zoning prerogatives of setback, bulk, height, land use intensity, buffering and parking which are the primary components of modern day zoning systems.

The case for zoning for trees was certified in 1949 in the famous Ayres v City Council of Los Angeles. In the Ayres case a subdivision developer was required by the planning commission to provide a planted buffer near the intersection of Arizona Avenue and Sepulveda Boulevard. The buffer was primarily a safety feature but it did allow space on a development site to be devoted to planting. Something developers had not done previously in a voluntary perspective. Today, it is more common to zone parts of building sites as places to plant trees and other vegetation.

Zoning for trees may be referred to as ‘green laws,’ a sobriquet for regulations that support or promote nature in the city. Green laws are generally of three types. They include landscape regulations, tree ordinances or comprehensive land development codes. All three maintain nature and promote the protection, preservation and planting of trees as an essential element of any community’s infrastructure.

“Green Laws”

Landscape regulations, often referred to as landscape codes essentially have been written to preserve locations on building site where trees and vegetation are allowed to grow. This form of green law typically provide for the design and planting of such site facilities as street yards, parking lots, site service areas, landscape buffers, visual screens, irrigation hydrozones, visual screens, and design of yard plantings that serve a variety of uses. They may also be habitat preservation areas that preserve wetlands, stream bank buffers, forest floors, waterfront yards or old landmark trees. These plantable areas are essential elements of any building site for which zoning regulations can be established. Plantable areas of a building site occur in predictable locations as can be seen in Fig. 1.0. They are often referred to as landscape design components, or design components and collectively they can be called the essential ‘geography of the development site.’^.1.Fig. 2.0 set forth some of the more common design components contained within landscape codes and each component provides a recognizable and consistent planting location on a building site, be it a lot, tract or neighborhood. Without sufficient planting sites, trees can not be planted.

_________________ ______________________ _________________________

Designation ………………………..Location…………………………..Purpose……………..

Street Tree Planting Area Along Street ROW Public Tree Plantings

Street Yard Between Building and Street Beautify Street

Street Wall Adjacent To Building Facing A Street Screen, Soften Building

Foundation Wall Between A Building And A VUA Improve Pedestrian Areas

Vehicular Use Area Interior Islands, Medians, Bays In Parking Lots Shade Pavements & Cars

VUA Screen Between Cars And Conflicting Land Use Screening Vehicles From View

Side Yard Buffer Buffering Conflicting Land Use At Side Screening Neighbors

Rear Yard Buffer Buffering Conflicting Land Use At Rear Screening Neighbors

Habitat Preservation Area Preserved Wetland, Tree Grove or Forest Protecting Sensitive Land

Irrigation Hydrozones Site Irrigation Conservation Zones Reduce Waste Of Water

Stream Bank Buffer Between Development and Streams Filters Storm Water

_________________ ______________________ _________________________

Fig. 3.0 Geography of a Development Site

The total of all plantable areas, often called permeable areas comprise the open space system of any building site. The open space in square footage divided by the total site area provides the open space ratio of a building site. The higher the open space ration of a building site the better. Open space ratios in excess of fifty percent can be considered excellent. An open space ratio of thirty percent is considered good while an open space ratio less than ten percent is poor.

But landscape codes also provide ‘standards’ for the design and planting of trees, tree species diversification, tree preservation and tree protection. Communities by zoning for trees are also creating standards to protect tree canopy, provide for shade, detain storm water run off, abate erosion, and cool hot urban environments. Trees in the city provide many services and are an important part of any building site.

In most communities, the reason for a landscape code is the protection of the public health, safety and welfare by placing regulation on lot compatibility, damages to natural systems, water use conservation, and on site storm water management. Some of the better codes, Mandeville, Louisiana for instance, encourage habitat preservation as a storm water management strategy so that their so called preserved ‘Greenbelts’ not only save trees but screen neighbors, add to the beauty of the community and filter and manage storm water. ^.2. Other code regulations place obligations on those that provide landscape design, grounds maintenance, arboriculture or landscape construction services. Still other landscape codes place a emphasis on tree protection during construction and proper methods of planting.

Landscape regulations are among the fastest growing aspects of zoning. Only dating back to the late 1960’s when the first landscape regulations were first written in South Carolina and Florida, they are now rapidly being adopted as zoning law in almost every city larger than fifty thousand inhabitants.

Tree ordinances, the oldest of the green laws, dating back to the 1930’s are often stand alone community regulations that are part of the municipal code but not part of the zoning ordinance. Not being included within zoning makes these green laws not very effective in maintaining nature in the city simply because they do not carry the police power of zoning but only the will of the community to enforce them from the general code book. More often than not, they apply only to trees on public land and are not very comprehensive. Tree management ordinances advocated by such organizations as the International Society of Arboriculture (ISA) set standards for the care of trees in American cities and towns. Many tree laws regulate the practice of arboriculture and set up municipal urban forestry programs, establish ‘tree’ boards and institute licensing for arborist. ^.3^.One recent study of tree ordinances from California points out that this type of ordinance is focused entirely on single trees and their management. These ordinances fail to recognize the importance of native habitat protection, design or site development opportunities for trees.^.4^.To many tree ordinances deal with issues of jurisdiction, tree policy, citizen assistance, licensing arborists, tree abuse and street trees and fail to recognize the relationship between zoning and trees.

Tree ordinances are usually one of three main types. They are tree preservation ordinances created to protect trees. The most common form is street tree ordinances that regulate and protect and assist in the maintenance of trees on public lands along streets. And the least common are development tree ordinances. The later are generally known as landscaping ordinances because they affect total site landscaping as well as trees. Planting standards are not very sophisticated and they are seldom tailored to specific parts of a zoned development site. This form of tree ordinance does not stress design as much as it does tree planting. A variant found in some communities is called a ‘view ordinance.’ This type of tree ordinance is created to remove conflicts between property owners when trees block views or sunlight. ^{.5 .}This concern is so important in Santa Monica, California for instance that tree plantings and hedges are completely controlled from blocking views to the sea and the mountains by city administrators. Planting a hedge of grove of trees is highly restricted by zoning in some communities.

The better tree ordinances however are contained within landscape codes, not separate from them. Tree regulations should be harmonized into landscape codes and must be related to site development, zoning and design. When tree ordinances are isolated from zoning, they are focused only on trees, and not how trees fit in with development or how the may promote community health, safety and welfare.

From a recent study of community tree ordinances it is clear that most contemporary tree ordinances have been written to protect and preserve trees rather than to support the needs of zoning, land use, development or design. A study of tree laws was conducted for the purpose of writing this paper. The study compared tree ordinances promoted by the USDA Forest Service to selected ordinances from other communities. The Forest Service Tree Ordinance Index is thought to be representative of typical tree ordinances found in American Communities.^.6. A total of fifty community tree laws were studied for the purposes of defining the essential provisions of a well written tree law. No attempt was made to rank them, classify them by type or to determine if the ordinances were contained with a city Municipal Code or Zoning Ordinance. Some of the ordinances were applied to public land, some to private and a few were actually model codes promulgated by agencies, universities or researchers. The study even included a model code from the LSU Green Law Research Project that was written several years ago and adopted in several communities around the country. As a result of this work, Fig 3.0 below illustrates the most common regulations found in municipal tree ordinances.

_________________ ______________________ _________________________

Code Provision …………………..Purpose…………………………………….……………..

CONTEXTUAL

Short title Ordinance title and location within the municipal code

Policies Regarding Trees General policy toward preservation, .protection, plantings and tree care

Tree Care License Licenses, qualifications, fees

Definitions Technical definitions concerning the code

Purpose And Intent/Applicability Specific purpose of the tree ordinance

TECHNICAL

Tree Inventory/Tree Survey Tree Inventory and Analysis

Tree Disposal Requirements for disposal of vegetation

Hazardous/Diseased Trees Definition of hazardous trees

Tree Protection/Protective Fencing Tree protection during construction

Tree Preservation Credits Incentives toward preserving trees

Pruning/Planting Standards Technical operations toward trees

Tree Care Specifications Arboricultural operations

Tree Planting Tree planting operations

Tree Species Botanical and horticultural operations

Landmark /Heritage Trees Special tree protection and preservation

Planting Yards Required planting locations on development sites

Landscape And Tree Plans Tree plantings plans and specifications

Tree Protection Areas Preserved habitats for trees

Canopy Requirements Standards for replanting of trees

Landscape Requirements Standards for other plantings on development sites

Street And Park Trees Special requirements for public tree care

Public/Private Trees Policy toward public and private trees

ADMINISTRATIVE

Submittal of Plans Procedures for submitting review documents

Permits Required permits for tree removal/planting/pruning/disposal

Duties of Urban Forestry/Arborist Administrative staff responsibility

Duties of the Administrator Administrative staff responsibility/procedures

Tree Advisory Board Citizen Oversight/Advisory Tree and Landscape Commission

Enforcement & Penalty Corrective Mechanisms

Hearings and Appeals Public Notice and Due Process Proceedings

Emergency Waiver Requirements concerning trees under special conditions

Severability/Repealer

Effective Date

_________________ ______________________ _________________________

Fig. 3.0 Common Tree Ordinance Provisions

Planners who want to draft a community tree ordinance would do well to include most of the contextual, technical and administrative standards listed above.

Few of the tree ordinances studied deal with zoning issues. All of these examples deal singularly with tree care in one form or the other. Some of the better ordinances in this study regulate tree preservation and planting as well, and this is a positive step for tree ordinances to take. Some of the better tree ordinances are seen in Fig 4.0 below. The contemporary history of tree ordinances can be seen by reviewing the fifty (50) ordinances in this study. There is a trend in the way the ordinances have being written. The earliest ordinance, the Municipal Tree Manual-Standard Municipal Ordinance dates to the 1950’s and clearly shows that the first ordinances were written to support the development of the arborist industry. This MTM ordinance, as it is called, and those that followed in the 60’s and 70’s did this by establishing municipal forestry programs, developing shade tree commissions and hiring municipal arborists. The California Guidelines Model, one of the most contemporary of the featured ordinances, although broader in some respects, still puts forward the basic format of the 1950’s ordinance design. Some of the contemporary ordinances such as Charlotte, Palo Alto and Gwinnett County and Baton Rouge are moving away from this trend and provide regulation for tree preservation and replanting.

__________________ ______________________ ________________________

………………………..…..…........................Community…………Title………………………….…………

Austin, Texas- Ordinance 960328-B

Boca Raton, Florida- Article II Trees

Baton Rouge, Louisiana- UDC Chapter 18 Landscape And Trees

Charlotte North Carolina- Chapter 21, Trees

Georgia Forestry Commission- Framework Ordinance

Gwinnett County, Georgia-Tree Ordinance

Howard County, Maryland- Subtitle 12 Forest Conservation

Miami-Dade, Florida- Tree Protection Ordinance

Palo Alto, California- Chapter 18-10 Tree Preservation

Raleigh North Carolina- Chapter 8 Trees And Vegetation

Santa Cruz, California- Chapter 9.56 Preservation of Historic Trees

Southlake, Texas- Ordinance 585-B Tree Preservation Ordinance

__________________ ______________________ ________________________

Fig. 4.0 Selected Tree Ordinances, LSU Tree Ordinance Index

The Howard County, Santa Cruz and Southlake ordinances are very good contemporary ordinances that are expanding the definition of what a tree ordinance can be. In the case of Howard it is forest preservation, with Cruz it is preservation and protection of old trees and with Southlake it is enforcement and integration with the community landscape code. The LSU Tree Ordinance Index is well worth studying by any planning commission wishing to write a tree ordinance from scratch.

It is common for tree ordinances to not address zoning, development or design. All are measures, strongly related to the development and management of the urban forest. Some of the contemporary ordinances from this study such as Collier County, Florida, Chapel Hill, North Carolina, Coral Spring, Florida and Lexington, Kentucky, while not making the LSU Index are becoming better integrated with landscape codes that have become part of municipal zoning regulation since tree ordinances came into popular use in the 1960’s.

While many communities enact ordinances merely for beauty or economic development, there are other important reasons why these codes are written. In recent years Davis, California enacted a landscape ordinance for solar control, particularly in regards to parking lots. Near by Irvine, California, enacted an ordinance to promote sustainability which is a form or recycling natural resources and energy. Santa Monica, California in Los Angeles county, is known as the ‘sustainable city’ and recovers all rain that falls that on the city to recapture pollutants before they find their way into Santa Monica bay. They use planting areas on building sites to soak up storm water to minimize run off .

Many communities in Florida, such as Lake Mary and St. Lucie County, base their ordinances on the need to conserve and reuse irrigation water. Collier County on the west coast and Volusia County on the east coast of Florida both require on-site storm water management and have standards that call for storm water facilities. Some of the new Georgia codes are directed toward sustaining tree canopy and preventing soil erosion. These codes call for a certain density of trees on all development sites. Texas codes are being written to include more shade within vehicular use areas. Austin recently drafted new language that will make parking lots cooler. Louisiana is exploring on-site storm water management and green parking lot design. Too much water is a problem in Louisiana so the Louisiana Department of Environmental Quality is working on a model landscape code that will help clean the state’s coastal waters. Maryland and Virginia have recognized the same problem for over a decade so many of their local codes call for forest preservation. Carolinas codes are being written to provide for stated numbers of trees per acre. These codes are concerned with canopy standards, shade requirements and tree preservation.

Tree Ordinance by Design

There are new directions that tree laws might take that will bring them more in line with zoning theory and put the power of police zoning to work preserving nature in the city. There are several directions or messages that that might be considered.

Tree ordinances and landscape codes, both working to preserve, protect and replant nature in the city need to be combined rather than competitive or overlapping. This is a problem. The two types of green laws do not work together in many communities. The Chapel Hill Ordinance, is a good example of how tree ordinances need to be designed to be integrated in their approach to preserving nature on a building site. Chapel Hill’s ordinance for example is based upon integrating the tree and landscape code into the zoning ordinance in the form of site design standards. These standards including regulations for critical areas, habitat preservation (especially of ‘significant stands’), tree care, tree protection, landscaping, screening, buffering, parking lot design, open space, integrated management practices, lighting, storm water management and erosion/sedimentation control. They are all integrated into the zoning code so they become tangible elements of any building program from the very beginning.

This code utilizes a more low impact development (LID) approach to tree issues and is much more integrated in concept.

Contemporary tree ordinances need to be “harmonized” or woven together to be part of the same body of municipal law. An examination of tree law vocabulary as seen in Appendix A gives evidence of the need for integration. All green laws need to be contained with zoning laws and must emanate from land use and not be just part of a community’s general body of law that dictates land use from outside the zoning code. In other words, green laws need to enhance zoning, not just put limits on land development which is what many tree laws do.

One community in Texas for instance contacted the University recently to say they needed help in drafting a tree law. When asked if they had a zoning ordinance to place the law within context, they demurred. This little community does not have zoning so their tree law would not have the backing authority of zoning, and hence could not be properly enforced. This tree law will dictate rather than enhance zoning and land development.. One further observation is worthy of note. The majority of municipal tree law pertains to trees on public land or simply street trees and do not even approach the zoning code! This form of tree law that is very common pertains to tree care, primarily pruning, shaping, removals and treatment for insects, disease and systemic problems. Now this is important but do you see the point?

The second message is that tree laws need to be more concerned with root space rather than canopy area.

Many newer tree laws that focus on tree density are based upon canopy standards, drip line calculations or shadow pattern and not available planting area. To get root space, areas of building sites need to be set aside for planting or tree preservation. The Fulton Country, Georgia ordinance is a case in point.

The purpose of Fulton is to cultivate and encourage a high level of tree preservation through administrative guidelines rather than implemented regulations within the zoning ordinance. The code is designed to provide standards for the preservation of trees as part of the land development, building construction and timber harvest processes. It is not the intent of this ordinance to regulate individual properties that must follow the rules of zoning. The requirements kick in only when activities require a land disturbance permit, a building permit or timber harvest permit. Zoning has nothing to do with this ordinance so every action is voluntary. Certain benefits are cited to the citizens of Fulton County. They point out that preserving trees will control soil erosion, moderate of storm water runoff, improve water quality, intercept airborne particulate matter and the reduce air pollutant loads. Enhanced to wildlife habitat is also mentioned as are the reduction of noise and glare, climate moderation, aesthetics, scenic quality and increased property value. No mention is made of zoning or how the tree preservation ordinance increases the community’s ability to zone effectively for trees or even land use, bulk, height, set back, screening and buffering.^.7.

A third message is the arborist’s meditation on the single lone specimen tree. This might be a tree found standing by itself in a parking lot, along a road way, in park or on someone’s lawn. A tree standing tall and free in all of its naked glory. A tree with a significant straight bole, prominent central leaders and delicate branching that waife irascible leaves, all basking in the warmth of full sunlight and bearing a perfect east-west orientation. Trees in nature do not grow like this. Writers, crafters and designers of tree laws should be at least equally concerned with conserving habitat and a mixture of vegetation and its dependent wildlife rather than just preserving specimen trees to be pruned and maintained on a regular basis by those in the aboricultural industry. Nature in the city needs to be in its natural configuration as much as practical. Irregular meadows with substantial tree groves, treed forest edges, wetlands, stream banks, marshes, recharge areas wildlife habitat and general open spaces provide places for trees to grow in the urban forest. Habitat preservation should be a prime goal of most tree laws, specimen tree preservation a secondary goal. Better tree laws can be written to protect existing treed areas or to replant natural forests in places where development has changed conditions. Rebuilding the urban forest by moving the forest around development is easier to do than preserving trees within development areas. This might be a tree policy worth pursuing

Fourthly, the USDA Forest Service recently released a study concerning the size of trees within the urban forest. This so called “large tree argument” indicates that large-stature trees are better within the city than small trees. Simply because the benefits of trees are multiplied as the tree grows bigger. When it comes to trees, size, they claim, really does matter. The authors of this philosophy argue that increased benefits in regard to trees result in reduction in storm water run off; improvement in local air, soil and water quality; reductions in atmospheric carbon dioxide. Further they point out big trees provide more wildlife habitat; increase property values and enhance the attractiveness of a community.^.8.They make a strong case for big trees with their position that large trees are what urban forests need but this is a faulty argument in light of zoning practices.

Large trees only is a mono-culturist’s thinking, not indifferent from the way Indiana corn farmers think about their rural landscape. In the city, a variety of planting spaces exist and various growing conditions result from land development activities largely as a result of zoning.. It is better to use trees and other landscape materials of different sizes, textures and character and then layer them into tree groves within available planting spaces. From a wildlife habitat point of view this is certainly more beneficial Again, the argument for large trees or small trees fails to think about zoning and land development issues but concentrates on saving the perfect tree. Many of which may not be perfect.

Finally, even contemporary tree laws and recommendations for their drafting fail to recognize the importance of harmonized codes and codes based upon zoning, site development and design. Single issue landscape codes that deal only with trees fail to see new trends that are developing in community design, These new trends, on-site storm water management, green parking, low impact development, smart growth and new urbanism may completely undo the way we presently think about writing tree ordinances. They will offer new possibilities for writing creative harmonized tree ordinances and will be much different in message than the MTM ordinance mentioned previously which is the foundation to most of the history of contemporary tree laws in this country.^.9.

The best way to insure that trees are seen as green infrastructure is to make sure that tree laws recognize design and are contained within, (harmonized) with landscape codes and landscape regulations both of which are codified within community zoning laws. This will not be an easy task but the trend has started. Communities such as Baton Rouge, LA; Collier County, FL; Columbia, S.C; Fairfax County, VA; Greensboro, N.C.; Gwinnette County, GA; Howard County, MD; Lexington, S.C.; Orlando, FL; and Marco Island, Florida have enacted some comprehensive green laws that see trees as an important element of zoning that have implications for environment, conservation, storm water management, open space and civic design. This is a positive trend for the future for tree laws.

How to harmonize community landscape codes tree ordinances? The answer is complex but we know for sure that it will be the role of planning officials, landscape administrators and staff to make it happen. ^.10.

Code Administration

As more and more cities enact integrated landscape codes that incorporate tree preservation, habitat protection and storm water management regulations code administrators and planners will need to improve their knowledge of plant materials, habitat protection, urban planting technology, irrigation, storm water and design issues. Perhaps, even more importantly, planners who work as code administrators, many will need to go through vigorous on the job training to learn how to interpret landscape plans, tree preservation plans, landscape construction drawings, tree surveys, design details and written landscape specifications that will be submitted for permits. Planners will need to understand how to write, review and make needed improvements to the landscape code they will be called upon to draft, revise or administrator.

The job of a landscape code administrator who will be in charge of tree zoning compliance is very complex. This is largely due to the many things a code administrator must know and the various duties that are assigned to a person in this position, as seen in Fig. no. 5.0 below. Planners who do this type of work must possess some understanding of landscape architecture, horticulture, urban arboriculture, urban natural systems and basic site engineering. To protect nature in the city, the code administrator must be responsible for plan review, site inspection, issuing permits and working with developers, builders, arborists and designers. They may need to be able to organize a tree bank program, operate a community tree nursery and understand how to read tree surveys and tree planting plans. This is an important job, planners must rise to the occasion if nature in the city is to be part of our urban fabric.

_________________ ______________________ _________________________

……………………The Many Duties Of A Landscape Administrator…….……………..

Advise community leaders and the general public on matters of nature

Organize a local tree/landscape advisory commission

Write and amend local zoning laws to include landscape & tree zoning

Write standard specifications for tree care, and plant material installation

Provide assistance to other units of local government in regard to trees

Work closely with the city landscape architect or arborist

Work with private developers, architects, engineers, landscape architects

Review preliminary landscape plans

Review Tree Surveys & Tree Protection Plans

Review and approve final landscape plans and specifications

Write reports and issue permits

Conduct field inspections

Manage Community Street Tree and Open Space Plans

Complete continuing education or on the job training on technical topics

Manage staff & budget

_________________ ______________________ _________________________

Fig. 5.0 Landscape Code Administrator Duties

It might be argued that landscape code administration will be one of the greatest employment growth areas for planners, arborists, landscape architects, urban foresters and horticulturists in the coming years as more and more cities write landscape codes to manage the green infrastructure of the community.

Evolving landscape codes are causing the work of code administrators, to change, and change rapidly. As nature’s agent, if landscape administrators are to protect nature in the city, they must undertake continuous training to keep up with changes in zoning law, landscape codes, tree management science and urban design. It will not be easy, but it will be worth it if we can keep nature in the city by zoning for trees.

Appendix A-Standard Tree Ordinance Vocabulary

___________________________________________________________

Arboricultural Treatments. Arboricultural treatments" means all services, treatments or operations involving trimming, pruning, spraying, injecting, fertilizing, cabling, surgery work, removal of and cutting above or below ground level of a tree.

…………. ………………………………….. …………………….Missoula, Montana

Arborist, Certified. One who is well-versed in the art of arboriculture, including tree surgery, the prevention and cure of tree diseases, and the control of insects, and who has International Society of Arboriculture (ISA) Arborist Certification…………

…………………………………...………………………………Miami-Dade, Florida

Buffering. The use of landscaping along with berms, walls or decorative fences that at least partially and periodically obstruct the view from the street........Austin, Texas.

Caliper Means the minimum trunk diameter of a replacement tree as measured at a predetermined point of measurement. Trunk diameter for trees up to four inches is to be measured six inches above the soil line. All trees over four inches in diameter will be measured 12 inches above the soil line. …………..……..Volusia County, Florida

Canopy Cover. Means the area above ground which is covered by the trunk and branches of the tree………………………………………………… Tigard, Oregon

Critial Root Zone,CRZ, The area of tree roots within the crown dripline, this is generally defined as a circle with a radius extending from the tree trunk to a point no less than the farthest crown dripline………………….…...Columbia, South Carolina.

Crownspread. Means the distance from the ends of the branches on one side of the tree, through the trunk, to the ends of the branches on the outermost branches on the other side……………………………………………………..Germantown, Tennessee

DBH. Refers to ‘diameter at breast height’ which means the diameter of the trunk, at its maximum cross section, measured 54 inches (4 1/2 feet) above mean ground level at the base of the trunk.. ……………………………………………Ashland, Oregon

Density Factor For The Site, DFS. A unit of measure to prescribe and calculate required tree coverage on a site based upon tree size…..Columbia, South Carolina

Dripline Area. Means the area within X distance from the perimeter of the trunk of the tree at four and one-half feet above natural grade where X equals a distance ten times the diameter of the truck as measured four and one-half feet above natural grade……………………………………………………….….Palo Alto, California

Impervious Surface Percentage. An site intensity measurement of the impervious surface of a building site. .....................................................West Lafayette, Indiana.

Habitat Preservation Area, HPA. An area of a site in which the entire natural habitat is unchanged and protected for the preservation of trees, storm water infiltration or wildlife. ………………………….……Louisiana State University

Hatracking. The flat cutting of the top of a tree, severing the leader or leaders, or the removal of any branch three inches or greater in diameter at any point other than the branch collar, i.e., that point where the lateral branches meet the main trunk……

………………………..…………………………………..…….Miami-Dade, Florida

Hazard or Hazardous. Means a tree or part of a tree that has a high potential for failure and falling on a nearby object because of dead or dying branches, roots or trunk……………… …………………………………………Passadena, California

Heritage and Specimen Planting. Shall mean any tree, grove, shrub, hedge or other planting which is determined to have special significance to the community………. …………………………………………………………………..Milpitas, California

Land Altering Activity. Any change to existing land which would physically alter the existing conditions and vegetative cover on the land.......Shreveport, Louisiana.

Landmark Trees. Tree or trees as defined on a list of trees enunciated and established by the Bedford Town Board, with such list being filed in the office of the Bedford Town Clerk.

Net Lot Area. The area within lot boundaries of all lands comprising the building site.........................................................................................Dade County, Florida.

Opacity. An imaginary vertical plane extending from the established grade to a required height of which a required percent of the vertical plane shall be visually screened from adjacent property use.... …………………………......Dublin, Ohio.

Percent Minimum Canopy. The amount of existing tree canopy an Applicant must preserve based on the zoning designation of the land to be developed….Fayetteville, Arkansas

Perimeter Landscape Strip. Is a landscaped area which separates the vehicular use area from adjoining property and/or public right-of-way..........Little Rock, Arkansas.

Plantable Area: The pervious surface area expressed in square footage available for the preservation or planting of vegetation.....................................Alpharetta, Georgia.

Prohibited Tree Species. Those tree species that are detrimental to native plants, native wildlife, ecosystems, human health and/or safety and welfare. This article incorporates by reference the Miami-Dade County Landscape Manual listing of prohibited species……………………………………………….Miami-Dade, Florida

Protected Tree. All mangrove trees and cypress trees, regardless of diameter, shall be defined as protected trees………………………………………...Tampa, Florida

Protective Barrier means a physical structure limiting access to a protected tree, composed of wood or other suitable materials, which ensures compliance with the

intent of this article………………………………….……….Biloxi, Mississippi

Public Trees. shall include all shade and ornamental trees or shrubs now or hereafter growing on any street, park or public place…………………….…….Portland, Maine

Reforestation. Means the establishment, in accordance with the Howard County Forest Conservation Manual, of new forest cover to replace forest resources lost because of development activities……………...…………Howard County, Maryland.

Riparian Buffer. A biological community consisting of trees, woody shrubs and groundcover that exists along the banks of rivers, creeks or intermittent and perennial streams…………………………….……………………………Fayetteville, Arkansas

Significant Tree. Significant tree shall be any tree that is at least six (6) inches in

D.B.H…………………………………………...…………….Lynnwood, Washington

Street Trees. Street trees are herein defined as trees, shrubs, bushes, and all other woody vegetation on land lying between property lines on either side of all streets, avenues, or ways within the City………………...…..Municipal Tree Manual (MTM)

Street Yard. The street yard is the area of a lot which lies between the street right-of-way line and the actual front wall line of the building............….....Austin, Texas.

Topping. Topping is defined as the severe cutting back of tree limbs to stubs larger than three (3) inches in diameter within the tree's crown to such a degree so as to remove the normal canopy and disfigure the tree…….Georgia Framework Ordinance

Tree And Landscape Commission. Shall consist of nine (9) voting members

and several non-voting ex-officio members who shall be appointed by the Mayor-President with the approval of the Metropolitan Council and whose duties shall be to study of problems involving the City-Parish’s urban forest, determine needs, compose and annually review a City-Parish Urban Forestry Management Plan, and seek ways to implement needed work……..Baton Rouge, Louisiana

Tree Bank. A tree bank fund is established by the City to provide an

opportunity to make a cash payment to the City in lieu of providing required

landscape material. …………………………………..Altamonte Springs, Florida.

Tree-Class A. Any self supporting woody plant of a species which normally grows to an overall height of at least fifty (50) feet.………………......Covington, Louisiana.

Tree-Class B. Any self supporting woody plant of a species which normally grows to an overall height between thirty (30) and fifty (50) feet…......Covington, Louisiana.

Tree-Class C. Any self supporting small tree or large shrub of a species which normally grows to an overall height between fifteen (15) and thirty (30) feet…......Covington, Louisiana.

Tree Conservation Area, TCA. A Tree Conservation Area is one or more areas of a site which includes existing trees and their critical root zones. The purpose of the TCA is to encourage the preservation of healthy trees that are four (4) inches or greater in diameter at breast height………………….….Greensboro, North, Carolina

Tree Cover Requirements. All developments requiring submission and approval of a site plan shall include the preservation and planting of trees on the site to the extent that, at maturity of ten years, minimum tree cover s(10-20% of site) shall be provided……………………………………………..……..Fairfax, County, Virginia

Tree Density Unit (TDU). A credit assigned to a tree, based on the diameter of the tree, in accordance with tables contained in this ordinance…………………………. ……………………………………………………………Gwinnett County, Georgia.