I am broadly interested in understanding links between plant-level processes and ecosystem processes. I am especially interested in exploring how these organism-ecosystem links are affected by human activities (e.g. atmospheric nitrogen deposition,  climate change, and land management).  Most of my work explores the impacts of these human activities on plant-ecosystem links within two general themes: (1) the patterns and physiological mechanisms by which plants respond to perturbations in the carbon (C) and nitrogen (N) cycles and (2) the patterns and mechanisms by which individual plants affect C and N cycles.  I address these questions through research that integrates manipulative field experiments with modeling techniques. My experimental approach spans a broad a range of techniques, from the physiological level to the ecosystem level, allowing me to explore links among different levels of ecological organization.