We examine mechanisms that underlie species coexistence and patterns of diversity. Research in the Gilbert lab takes place in a number of different ecosystems, ranging from boreal to tropical, and working with study organisms as different as tree seedlings, plankton and mosquito larvae. We use a combination of field studies, mathematical models and statistical approaches to investigate processes that maintain diversity. Most of our research focuses on species-environment relationships, how these structure and are structured by species interactions, and how they respond to fluctuations through time and space. We use this knowledge to understand the impacts of global changes, such as species invasions, climate change and habitat fragmentation.