Assessing the impact of climate change on urban tree species selection: A case study in Philadelphia

Abstract

Rapid climate change can have a significant impact on the distribution and biology of trees. As a proactive adaptation measure, cities can stock their urban forests with tree species that will perform well in predicted future climates. This article presents a method for assessing the suitability of urban tree species for predicted future climates through a case study in Philadelphia. Changes of the optimal distribution ranges of major tree species planted in Philadelphia were evaluated by comparing the climate envelopes of those species with the predicted climate in the midcentury. Influences of climate change on major tree disease and pests in Philadelphia were also assessed by inspecting the potential effects of climate change on the biology of pathogens and pests. The results indicate that the future climate in Philadelphia will become less optimal for 10 tree species, while two species will thrive. Major pests and diseases in Philadelphia will generally become more problematic but occurrences of several diseases and pests may decline. It was suggested that the optimal distribution ranges of trees and their maintenance needs must be considered at the same time when selecting tree species for urban greening projects. Overall, the predicted climate change in Philadelphia will likely increase the choices of tree species for the city. © 2009 by the Society of American Foresters.