The central aim of my research is to elucidate the processes driving fluctuations in population abundance across time and space. Among the many factors that can influence populations, I am particularly interested in those that operate over broad spatial scales and/or are the result of human activities. Most of my experience in natural systems comes from studying insect populations. Of late, much of my research focuses on forest defoliating insects, trying to glean an understanding of their population dynamics and how their populations impact forest health. My approach blends field experiments, analysis of spatial data, and theoretical modeling.