Evaluating the impact of government land use policies on tree canopy coverage

Many cities around the world are experiencing the negative effects associated with not sustaining a sufficient level of tree canopy coverage. Tree canopy provides environmental benefits such as clean water and air, erosion prevention, climate control, and native species habitat and provides economic benefits such as higher housing values and lower energy expenditures. We study local government policies in a large U.S. metropolitan area (the Atlanta Metropolitan Statistical Area) to find which policies perform the best at preserving or increasing urban forests. Empirical analysis reveals that a set of effective tree ordinance clauses, zoning ordinances, and having high quality smart growth projects in the community all help in preserving tree canopy in economically and environmentally meaningful amounts. Other actions, such as simply having a tree ordinance, designating a key management person in charge of tree programs, the presence of a tree board, and multiple communication channels were shown to be ineffective for our data set. Because benefits from tree canopy accrue to the local government's budget, to residents and to business owners, the entire community should gain from the passage of effective policies to preserve their local tree canopy. Estimated economic benefits from preserving tree canopy through an effective set of public policies are in the range of $10–15 million annually in an average county, mostly due to savings on stormwater management.