His expertise is terrestrial ecosystem ecology and biogeochemistry, and his research focuses on understanding the biotic and abiotic controls over terrestrial biogeochemical cycling and ecosystem processes. Projects vary in scale from plot-level studies investigating the effects of disturbance and global change on ecosystem processes to large-scale analyses of the carbon, nitrogen and phosphorus cycles. His research intersects several major disciplines, including microbial ecology, soil science, biogeochemistry and ecosystem ecology, but the overall goal of his research is to understand how biotic and abiotic factors regulate carbon and nutrient cycling, the implications of those processes for ecosystem function, and the response of those phenomena to global environmental change.