Abstract
While the overall objective of municipal tree ordinances is to provide safe and attractive community forests, the approach to addressing this issue varies profoundly among municipalities. This study explores the relationship between community characteristics and municipal tree ordinances using data from 151 Illinois communities. Results show significant correlations between ordinance provisions and community ‘characteristics relating to wealth and education. Communities with higher mean income and level of education are more likely to have provisions biased toward the maintenance and protection of existing community trees, while communities where residents are less educated and poorer on average tend to have ordinances focused on community aesthetics and safety through resource improvement. Municipal governments, and the tree care professionals advising them, can use this information for guidance when revising or developing ordinances to match community preferences and objectives.
Tree ordinances are commonly enacted by municipalities to assign municipal authority, responsibility, and maintenance or management standards for trees on private and public land (Miller 1997; Bernhardt and Swiecki 1999). They are defined as regulations, authoritative rules, or laws of a municipal body that govern tree management beyond the limitations of federal and state statutes (Tereshkivich 1990). If properly developed and enforced, ordinances can promote health, safety, and welfare within the community (Abbey 1998). Tree ordinances also serve communities as vehicles to increase the likelihood of receiving funding through state and federal programs and to achieve recognition through the Tree City USA program (Fazio 1997, 1998).
Despite the existence of templates and guidelines for ordinance development, municipal tree ordinances (MTOs) are rarely similar among communities (Weber 1982). Following adoption of an ordinance, changes are enacted to better suit the social and biological structure of the community (Fazio 1997). In addition, Weber (1982) observed that ordinances, and resident attitudes toward ordinances, differ due to site characteristics, ethnic tradition, political and economic climate, and the legal framework of the community. Although attitude differences toward community forestry among demographic groups have been recognized, little academic research has addressed the relationship between community characteristics and tree ordinances (Abbey 1998).
MTOs differ not only among communities, but also among states and nations. Legislation in other nations differs considerably concerning management of trees on municipal land (Profous 1992). Within the United States, some states give municipalities greater sovereignty while others may be more restrictive or may authorize specific actions that may be performed by communities (Duerksen and Richman 1993). Because there are so many differences in laws underlying municipal tree ordinances, analysis must be carried out on a state-by-state basis.
Currently, at least 179 Illinois communities have adopted tree ordinances (Green et al. 1998). If present trends continue, interest and funding opportunities for urban forestry initiatives are likely to increase over the coming years, spurring the adoption of tree ordinances by additional communities. In many cases, municipal governments that are developing new tree ordinances have based their work on ordinances already formulated by other communities with little regard for management priority, resource availability, or cultural differences. Although ordinances may eventually evolve to fit the community, this process often occurs at the unnecessary expense of time and money.
To help communities develop appropriate ordinances, the specific relationship between identifiable demographic characteristics and the nature of ordinance provisions must be better understood. Socioeconomic and demographic population descriptors may provide aggregate data characterizing human population distributions. In a natural resource context, fishery and game managers use community characteristic information to create profiles of selected constituency segments in order to develop responsive management programs (Hall 1998). Local governments chart changes and trends in community characteristic distributions over time to provide background for policy decisions and to evaluate overall performance (Tyler Norris Associates 1997). The present study compares community characteristics of 151 Illinois communities having municipal tree ordinances to determine if relationships exist between community population characteristics and the existence of explicitly stated provisions in their ordinances. This information can be used by other local governments in planning and implementing policies and regulations that will be compatible with community preferences.
METHODS
A list of 170 Illinois communities that have a municipal tree ordinance was obtained from the Illinois Department of Natural Resources (IDNR), Division of Forest Resources, Springfield, Illinois. Communities known to have a tree ordinance, but which did not have one on file with the IDNR, were contacted to obtain a copy. All but 19 of the 170 contacted communities responded (88.8% response rate).The study included 151 municipal tree ordinances available as of July 2000. Presence or absence of 27 specific tree ordinance provisions was recorded for each community.
Community characteristic data were obtained from the U.S. Census Bureau 1990 census using ProFiler 3.01 software (Wessex, Inc. 1993). The range of values for each community characteristic variable was converted to a two-category ordinal variable by categorizing the values as being above or below the median. The median value was selected as the measure of central tendency most appropriate for dividing non-normally distributed quantitative data into categories for subsequent bivariate contingency table analysis (Green et al. 2000).
Data were analyzed using SPSS 8.0.0 (SPSS, Inc. 1997) to evaluate the relationship between community characteristic variables and presence or absence of tree ordinance provisions. Bivariate contingency table analysis with Chi-square test statistic was used (α=0.05) to accept or reject the null hypothesis of independence (Green et al. 2000).
RESULTS AND DISCUSSION
Illinois communities with tree ordinances were found to represent a wide range of community characteristics (Table 1). The study also found considerable differences between the number of specific provisions that are developed by the communities (Table 2). A majority of the communities with tree ordinances have specific provisions that require private property owners to care for trees adjacent to or located on their property, establish penalty fines for ordinance violations, regulate disease abatement, authorize municipal workers to enter private property, and establish and set guidelines for community tree boards. Few communities have provisions that establish and set guidelines for tree care personnel, require licensed tree care operations, or set guidelines for emergency removals.
Community characteristic variables that were found to have strong associations with ordinance provision variables were education level, annual per-capita income, average price of home, unemployment rate, residents living under the federal poverty level, and total population (Table 3). This finding suggests that community wealth and education may have the strongest influence on the tree ordinance composition of the community. Gender and race variables showed a moderate number of significant relationships with the presence of selected provisions. Age categories, however, yielded varied results. The 65 or older age group yielded a large number of significant relationships, while the 25 to 65 age group produced moderate significant relationships. The 25 and under age group variable had no significant correlation with ordinance provision variables. These findings may be related to a stronger involvement by retired residents in local politics. The community characteristic variables that showed little or no significant correlation with provision variables were proportion of residents who owned their homes in the municipality and those living in a single-head household.
The municipal tree board (TRBD) provision variable had the greatest number of significant associations with community characteristic variables. Higher income, price of home, population, and attainment of higher education were negatively associated with the TRBD provision, while poverty, unemployment, and lower educational attainment were positively correlated. The community forester (FRST) and other tree care personnel (OTHR) provision variables showed positive correlation with higher education and average price of home variables, while negative correlation was found with lower education. Communities characterized by lower population levels and lower levels of educational attainment and income among residents also were more likely to have an arborist license (ARBL) provision, which is counter to the correlations found with the FRST and OTHR provisions. These relationships indicated that communities with wealthier and better-educated residents were more likely to employ professional personnel to make tree care decisions, while communities with poorer and less-educated residents were more likely to delegate management responsibilities to a volunteer tree board and contract a private tree care industry to perform tree care. This may be due to the inability of smaller communities with poorer residents to employ a professional official—thus forcing the community to pool volunteer resources of knowledge and authority.
The topping (TOPG), curb distance (CURB), and stump removal (STMP) provisions were, in general, negatively associated with population, average income, average price of a home, and higher education but were positively correlated with unemployment and lower levels of education. This finding indicates that smaller communities with residents that have lower levels of income and education enact ordinances concerned with improving the present level of attractiveness and safety.
Preservation (PRSV) and prohibition of damages to trees (DAMG) provision variables were positively correlated with population, average income, average price of home, and higher levels of educational attainment, but negative associations were found with poverty, unemployment rates, and lower education levels. These provisions essentially make trees public property by requiring that tree preservation and replace-ment be practiced during land development. The disease abatement (DISE) and planting requirement (PREQ) provisions also showed various positive correlations with higher education, income, and average price of a home. These correlations show that communities with wealthier and better-educated residents are more likely to create ordinances that improve or preserve the current condition of trees.
The presence of permit (PRMT) and property lien (LIEN) provisions were positively correlated with higher education, average annual income, and average price of a home. These findings suggest that communities with wealthier residents have transferred more authority from individual property owners to a municipal authority and have sufficient personnel and funding to run an extensive permit and penalty program. No significant correlations with community characteristic variables were found for the RFRA, DUTY, PRVT, EDUC, and COMP provision variables.
While communities may share similar ordinance provisions to address specific management issues, large differences exist in the actual standards established (Table 4). Communities may not always include references within the tree ordinance to other municipal ordinances, or documents outside the municipal code that are relevant to tree care, even though tree care may indeed be addressed in another document (Cooper 1996). Specifically, provisions that authorize personnel to care for trees and establish penalty fines can be found in sections of a municipal code that do not pertain specifically to trees. This may have impacted the number of observed correlations between community characteristics and municipal tree ordinance provision variables.
A closely related problem was that many of the communities in the study have arboricultural specifications manuals in which guidelines and regulations for tree planting, maintenance, and removals are specified. Keeping the manuals outside of the municipal code allows the guidelines and regulations to be flexible, incorporating changes without the engagement of a potentially slow community political process (Fazio 1998). Because information contained within these manuals was not reviewed in this study, the number and nature of correlations between community characteristic variables and some arboricultural specifications and guidelines may differ somewhat from the values expressed here.
CONCLUSIONS
Correlations between a community’s characteristics and municipal tree ordinance content have been identified. Community characteristic variables most commonly correlated with specific municipal tree ordinance provisions are education, poverty, unemployment, average income, average price of home, and total population. Larger communities, and those with wealthier and better-educated residents, are more likely to have provisions geared toward preservation and protection of existing community natural resources, consequently restricting the ability of home owners to make tree-related decisions on their own property. These communities are likely to have ordinances that enact and set guidelines for tree care personnel, since they have more economic resources to create and maintain such a position. The communities also have provisions that set stringent permits, and liens for penalties, to enforce wider municipal authority.
Smaller communities, and those with poorer and less-educated residents, are more likely to rely on a tree board to make tree-related decisions, since they have less area to cover and fewer resources to provide for a tree care position. These communities appear to be more concerned with improving aesthetics and safety, given that they tend to have provisions requiring various improvements to the visual and engineering aspects of tree care in the community.
This study represents a first step toward the development of guidelines for communities seeking to update or develop tree ordinances that strike the best balance between municipal government objectives, home owner rights and responsibilities, expense, staffing, tree care quality, municipal forest integrity, and cultural preferences. Recognizing the existence of differences in the attitudes, economics, and the physical structure among communities can help municipal leaders develop better tree ordinances. Specifically, further efforts along these lines can be useful for the development of a decision support system, using socioeconomics to aid communities embarking on the potentially time-consuming and contentious process of ordinance development or revision.
Acknowledgments
Special thanks to the Illinois Department of Natural Resources and the communities involved for providing ordinances for analysis. Funding was provided by the Illinois Department of Natural Resources and Southern Illinois University, Department of Forestry.
- © 2001, International Society of Arboriculture. All rights reserved.