Topic | Description |
Findings (“Whereas”)
Vision and goals | Most codes begin with assertions of fact – acknowledging that the body enacting the ordinance has considered local conditions and assessed the potential costs and benefits of action. Findings, vision and goals establish the “why” of the ordinance; the remainder describes the “what” and “how.” |
Purpose | This Section recognizes the services and functions that trees provide as a collective asset to the entire community. This is where you lay out what you want to accomplish – your objectives. Concrete (and to the extent possible, measurable) objectives are necessary to determine whether the ordinance works as it’s intended. |
Definitions | Definitions are one of the most important ways an ordinance can be shaped to fit a community needs. They are not generic. Each item can be constructed differently for different purposes. For example, some communities define “significant trees” as trees of 6” DBH or greater; “specimen trees” as 24 inches DBH or greater, and “heritage trees” as those 32” DBH or greater which have demonstrable historic and cultural value. Your choices for these and other terms will influence how your ordinance works. |
Urban Forest Management Plan | Enacting an ordinance becomes extremely difficult without some degree of mutual understanding, if not consensus, among stakeholders. That’s one benefit of having an urban forest management plan in place. |
Equity | Historically, communities of color and immigrants have far less access to the benefits of nature, including green space and trees. These provisions direct resources to under-canopied neighborhoods and create cyclical maintenance systems to assure services aren’t provided mostly to those willing and able to contact the city. |
Agency Alignment | Different departments within municipal government deal with trees in one way or another. Common examples include public works and stormwater management, parks, transportation, schools. Each might aim for different departmental objectives. But, by aligning plans, agencies are better able to sequence projects, address potential impacts on trees and allocate resources most efficiently. |
Public Tree Removals | Most ordinances include provisions which spell out criteria for tree removal from parks and other public lands – and who decides whether the tree is cut or not. Often different rules are applied to different circumstances. |
Private Tree Removals | Most tree canopy in most communities is on privately-owned land. Given that development is a significant driver for tree removals, the criteria for conservation can be complex. Balancing private and public interests can be difficult and time consuming. But many communities do it effectively. |
Topic | Description |
Tree Categories | Removal requirements for significant trees differ for different categories. Often, “heritage trees” receive the most stringent protections, with other categories subject to looser rules. Street trees are generally dealt with separately as a publicly-owned asset. As a general rule, significant trees are defined as trees between 5” and 10” DBH. Many communities require permits to remove significant trees from private property for both construction and landscaping purposes. |
Hazardous Trees | Dead, dying and hazardous trees can be removed under different, often less stringent rules. Almost all communities require notice of intent to remove if possible. If owners do not comply with requests to remove the tree, many cities will do it themselves and bill the owner. |
Applicability and exemptions | Not all rules for removal affect every category of owner and requirements for each can differ from community to community. Publicly owned trees are generally subject to strong protections against removal without authorization from the city’s senior tree official. In many jurisdictions, single family homeowners are exempt from tree protections. In some, they’re allowed to cut one or two trees over a set time period without permit approval. |
Public Notice and Posting | Many communities require that owners (including public agencies) notify nearby residents and businesses about their plans to remove trees – even a single tree. Provisions include on-site signage as well as written and electronic notification. |
Appeals | Public participation in administrative proceedings will often result in appeals to overturn the decision to remove even one tree. Ordinances lay out detailed procedures for timing and handling of appeals. |
Mitigation | Almost all ordinances require the property owner to mitigate the loss of removals. The ordinance specifies how many trees must be replaced per tree removed; species and size; placement of new trees; and alternative methods of compliance. Establishing standards for mitigation, especially on private land, can be difficult – especially as the property interests of the owner must be balanced against the community’s need to sustain and grow its tree canopy. |
Valuation of removed trees | Valuation is the precursor to mitigation. There are long established rules for tree appraisal and valuation – often specified – that follow the Plant Appraisal Guide of the Council of Tree and Landscape Appraisers (CTLA). Some communities have found that these formulas aren’t adequate to capture the true value of lost trees because they overlook where trees are sited and the ecosystem benefits they provide. |
Landscape standards and practices manual including: | While specificity in an ordinance can be enormously helpful in applying and enforcing an ordinance, it can also make future changes more difficult. Some ordinances avoid continuing legislative amendments by creating a “landscape standards and practices” manual. Often detailed and illustrated, they describe specific owner responsibilities for removals, replacements, mitigation, native and invasive species as well as planting practices and protocols for different types of sites. Most include policies on native and invasive plants. |
Preferred and prohibited species lists | Not all trees are created equal. Most ordinances either include or reference credible lists of trees to be planted in various situations, and those invasive or undesirable trees that should be neither planted nor credited for retention. |
Topic | Description |
Parking lots | Mirroring current concerns about the impacts of excessive heat, many communities are strengthening landscape requirements for parking lots. Most apply these rules to new and fully renovated parking lots. Recent research by USDA Forest Service found significant reductions in ambient and surface temperatures in shaded lots – as well as lower temperatures in cars themselves. Lower interior temperatures reduce greenhouse gas emissions by slowing evaporation of fuel. |
Development on larger landscapes | Private tree ordinances overlap with zoning and development rules. Many communities set mandatory tree density requirements for larger developments – either by zoning classification or through rules for lot coverage. For example, Fairfax County VA requires that new residential properties in specific zoning classes ensure that 25 percent of the property will be covered by tree canopy in 20 years. Other cities require that a percentage of the lot be held as open space, with specified numbers or density of trees. Still others require trees in setbacks.
Public projects are managed differently but often are held to the same requirements as similar private projects. Some cities will require the city arborist to participate in site selection – identifying those potential sites which present lower potential for tree loss. |
Maintenance practices | Because of resource constraints, many cities limit maintenance activities to on-demand response for services requested by residents. This practice works against tree equity since residents of EJ neighborhoods are often reluctant to contact city officials. Best practices in tree ordinances include a requirement for regular cyclical maintenance in all neighborhoods. |
Natural areas management | Cities increasingly establish different management regimes for significant (generally publicly owned) patches of woodlands and natural areas – often applying best practices identified by the Natural Areas Conservancy |
Tree Board | Appointed by the City but operating under a charter established in a tree ordinance, a Tree Board can perform some or all of the following functions:
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Tree Fund | In most cases, cities establish a Tree Fund to serve as the repository of fees, fines and recompense paid by property owners pursuant to the requirements of the tree ordinance. The ordinance also specifies how funds can be used. Many direct resources to nonprofit organizations for planting projects on private land in EJ neighborhoods. Some use a portion of funds to pay for staff positions. Almost all place governance of the Tree Fund with the Tree Board. |
Annual reporting | Regular reports on the condition of a city’s urban forest are critical to good management. Most cities track trees removed and trees replaced during public and private development projects. Some cities provide periodic “condition reports” on different categories of public trees – streets, parks, etc. A growing number of municipalities have created public-facing, web-based tree |
Topic | Description |
maps which show individual (public) trees and provide some information about their status. These “open tree maps” promote public awareness of tree benefits, and foster mobilization of volunteer “tree stewards.”
(Note: These maps are based on inventories conducted periodically – on the ground – by professionals or trained volunteers.) | |
Program evaluation and monitoring | Most communities report program outcomes – for example, number of trees planted; status of heritage trees; acres of open space preserved. A few communities are exploring how to assess the actual impact on people of their tree conservation activities. Examples include tracking emergency room visits for respiratory problems and monitoring real-time ambient temperature or stormwater flow in select neighborhoods. |