Environmental Studies Knight Distinguished Lecture - Local vs Regional Constraints on Urban Biodiversity

Dr. Christopher Swan Professor Dept. of Geography & Environmental Systems University of Maryland, Baltimore County

Estimating the relative role of local versus regional scale factors structuring communities is now standard practice when studying species coexistence. The classic view that local factors such as abiotic fluctuations, environmental constraints and interspecific interactions needs to be understood in light of regional effects, where often these regional effects comprise long-distance dispersal, speciation, extinction, and shifts in species' distributions across geographic regions. With the rapid expansion of urban and other environments, species pool constraints maybe playing a much larger role than typically understood. The outcomes for community assembly in this regard remain to be completely studied, and may have implications for explaining patterns in biodiversity at local, regional, and inter-habitat spatial scales. Here, I will present the results of two studies from two very different systems, ponds representing the urban hygroscope, and urban forest vegetation to explain how human constraints on the regional species pool interact with beta diversity to generate different community assembly trajectories. The consequence is a more nuanced understanding of the role humans play in shaping urban biodiversity at multiple spatial scales. 

Zoom link available upon request at environmental@wustl.edu