Building Urban Forest Resilience to Sea Level Rise: A GIS-Based Climate Adaptation Tool for New York City

Abstract

Urban forests in coastal regions are vulnerable to changing climate conditions, especially sea level rise (SLR). Such climate change impacts add complexity for urban forest managers as they make decisions related to tree species selection. The New York City (NYC) Parks Department manages over 660,000 street trees, many of which occupy sites that are susceptible to saltwater flooding. In order to build a resilient urban tree canopy in these flood-prone zones, we ranked tree species based on their overall tolerance to coastal vulnerability factors such as high winds, salt spray, and soil salinity. Our results revealed that 16 of the 44 species ranked high in overall tolerance to these factors. We also developed a GIS-based tool, specific to NYC, which delineates three coastal tiers based on their susceptibility to coastal vulnerability factors using SLR projections for the 2100s. The species list combined with the GIS tool provides urban forest managers a method to assign tree species to different coastal tiers based on their ability to withstand coastal climate change impacts into the future. We provide details on how this tool was developed for NYC so other coastal cities can replicate this approach to creating a more resilient future coastal urban forest.