The level of effectiveness of tree ordinances can be influenced by many factors. Public knowledge, perception and support can play a major factor in the effectiveness of tree ordinances. Other influences are whether or not the ordinances are adequately enforced, environmental limitations affecting tree health/survival and financial resources. Since these factors will vary from place to place, even similar ordinances can have different results in different communities.

Although opinions can differ within cities, it is possible to objectively assess the performance of a tree ordinance. Assessment requires an evaluation of the ordinance and related regulations and evaluation of the urban forest itself. Even though ordinances vary widely in form, content and complexity, an effective tree ordinance should meet the following criteria:

These are key features of the ordinances.

• Goals – should be clearly stated and provisions should address the stated goals.
A clear statement of goals is essential and provides the basis for interpreting the ordinance and evaluating its effectiveness.
• Responsibility – should be designated and proper authority granted to commensurate with responsibility.
Responsibility is often laid upon the shoulders of one person, but is sometimes split between two or more positions. In most cases, the most effective management of urban forests is to have a single person responsible for overseeing all tree-related activities. This allows for better activities coordination and reduces conflict between departments. However, responsibility may be split between a tree commission, which sets policy and handles administrative duties, and staff, which is responsible for operations and enforcement. The tree program manager should be vested with the authority to carry out all responsibilities. It should be clear in the tree ordinance the link between responsibility and authority. However, in some ordinances responsibility appears to exceed authority. Urban forest management is likely to suffer when responsibilities are ill-defined or the authority to act is not granted.
• Flexibility – should be designed into the ordinance.
While ordinances should set standards, it is important that they allow for flexibility. If objective performance standards are set, then the arborist or forester is more easily directed as to how to implement the ordinance. This can reduce the need for overly detailed implementation standards and allows for the flexibility to make decisions on site-specific biological and physical factors. Usually, ordinances will have a process for appealing decisions. This allows for a degree of flexibility also in that it serves as a checks-and-balance against the authority of the manager. Unfortunately, appeals may also serve to undermine good urban forest management if they routinely allow pressure to override the decisions of the specialists.
• Enforcement methods – should be specified.
Enforcement is always an important aspect of any ordinance. However, many tree ordinances lack enforcement elements because nobody is specifically charged with this duty. In ordinances with enforcement provisions, many types of penalties are employed. Some of these include fines, forfeiture of performance bonds and jail terms. Many jurisdictions opt to require specific replacement plantings as penalties. Many of the penalties appear to be sufficient but only if consistent enforcement is in place to deter violations.
• Basic performance standards – should be set.
A tree ordinance should indicate which practices and conditions are acceptable and which are not. Besides stating what is regulated, an ordinance should set basic standards for performance. For instance, standards should be set to regulate canopy cover, amount of shade provided, permits required for tree removal, etc. If basic standards are not set, it is possible that all individual actions taken will conform with the ordinance, but that the overall goals of the ordinance are never achieved. Effective standards address the urban forest as a whole rather than focusing on individual trees.

These components reflect the background in which the ordinance is developed.

• Community support – should be garnered during development of the ordinance.
Community support is vital to ordinance effectiveness and should be considered a major factor in determining and implementing ordinances.
• Comprehensive management strategy – should be developed and implemented.
Properly applied, an ordinance can help facilitate good management. Improperly applied, ordinances can cause counterproductive practices, provide disincentives for conservation and undermine the sustainability of the urban forest. Although it is possible to structure an ordinance using a patterned approach, such ordinances are unlikely to be well integrated with a comprehensive urban forest management strategy.

Although meeting these criteria will not guarantee success, ordinances lacking one or more of these elements will definitely be handicapped.