I use mathematical tools to address ecological questions from a theoretical perspective as well as a statistical perspective. My work has crossed systems from plants to predators, from antler flies to Pacific salmon. My lab constructs general models of ecological systems at the population or community level. My work also includes collaborative work with empiricists on the structure of prairie communities. Major themes of my work include addressing the consequences of temporal fluctuations for ecological systems and investigating the mechanisms of coexistence in diverse communities. These are important questions in the context of predicted global climate change. In addition, I work with collaborators on student learning at the college science level, including student contracts, exam question formats, and tools to enhance the use of formative feedback.