Vulnerability of Common Urban Forest Species to Projected Climate Change and Practitioners Perceptions and Responses.

Abstract

While urban forests are often identified as part of climate change adaptation and mitigation strategies, less attention has been given to vulnerabilities urban trees may have to a changing climate and practitioners' response to those vulnerabilities. Yet, current planting and management decisions will impact how urban forests fare under future climatic conditions. We explore a case study of Mississauga (Ontario, Canada) to examine (1) if common urban forest species are vulnerable to two scenarios of projected climate change, (2) the experiences and responses of urban forestry practitioners to climate change, and (3) whether urban forestry practitioners' experience and practice are aligned with the vulnerability assessment. Vulnerabilities of 27 common species were examined based on 2071-2100 regional climate projections. Interviews were then conducted with practitioners working in the public and private sectors. The results suggest that the majority of examined species will be vulnerable to multiple conditions associated with projected climate. Practitioners all perceive recent changes in climate and extreme weather patterns, but do not prioritize future climate conditions in their species selection decisions. Moreover, they expressed uncertainty about how to make species selection decisions in light of climate change. Given the predicted vulnerabilities, alternative species need to be considered or more management resources (e.g., for watering) will be required to maintain the current composition. However, the lack of focus on future conditions by practitioners raises concerns, while also highlighting the need for more information about appropriate management strategies.