Zoom webinar link for remote attendees:
host: grad students (contact Sandra Emry)
Title: Global variation in the impacts of climate vs. species interactions for population performance
Understanding which ecological drivers most strongly impact population growth is a fundamental question in ecology, and particularly important in the face of simultaneous changes in multiple ecological drivers. Complicating matters, the relative response to ecological drivers could vary geographically (e.g., across populations within a given species). Here, I discuss work on how population response to two ecological drivers—climate and species interactions—varies across broad environmental gradients. I focus on an old hypothesis, first proposed by Darwin, that climate is more important for populations in temperate areas, but species interactions impact population growth more substantially in tropical areas.
I show multiple tests of this hypothesis from a variety of systems. I first outline a case study of one species that shows strong support for this hypothesis. I then outline results from a comprehensive test of this hypothesis using a meta-analysis approach synthesizing data across many species and at a global scale. I end by outlining how latitudinal variation in response to drivers might manifest into latitudinal variation in climate change impacts on populations and communities.