A macroecology of urban trees

A biogeography of urban plants has been challenging to place within ecological theory as biophysical and human drivers influence continental-scale urban plant distributions. Cities are found in nearly the entire global range of environmental conditions and within this breadth of conditions, cities can be either hotspots or depauperate of plant diversity. New frameworks are needed that provide an underlying mechanism to account for this large variability and that lead to predictions on how urban biodiversity responds to both societal and environmental drivers. Extending such urban plant macroecological frameworks to other taxa and across multiple continents may provide valuable insights.