The role of native species in urban forest planning and practice: A case study of Carolinian Canada

Abstract

In recent years, many North American municipalities have adopted urban forest management plans. These plans typically include ambitious tree planting goals, with a focus on increasing native species’ presence. Having a high percentage of native species can increase ecological integrity, but there are also benefits associated with planting non-native trees in urban forests. The possibility of using assisted migration as a way for cities to respond to climate change raises additional questions about the importance of managing for native species. This study explores the ways native tree species are treated in urban forestry planning and practice in light of on-going debates around ecological integrity, non-native benefits, and assisted migration through a case study of municipalities in Carolinian Canada (Ontario, Canada). In particular, we (1) examine the role of native species in urban forest management plans, (2) explore municipal foresters’ attitudes and actions related to native tree species, and (3) determine if municipalities with and without formal management plans are making different decisions regarding native tree species planting. The objectives are addressed by examining management plans and interviewing urban foresters from municipalities with and without formal plans. We found all of the municipalities with management plans emphasize native species, and many justify their planting as a way to increase ecological integrity. These municipalities are also considering more of the managerial aspects associated with native species than municipalities without a plan. However, only a fraction of species native to the region are available through nursery stock, meaning many native species are not planted by municipalities. Most municipalities are also passively practicing assisted migration without considering the ways it can be used as a climate change adaptation tool. The gaps between municipal plans and practice are discussed, as well as future research needed to help guide treatment of native species in urban forests.