My research is focused on the biosphere-atmosphere exchange of carbon dioxide, water vapor and energy in terrestrial ecosystems, and the interactions with climate, land use and ecophysiology. I am specifically interested in the effects of drought and climate change on carbon sequestration, and on ecosystem processes such as photosynthesis and transpiration. Further interests include the partitioning of ecosystem fluxes, carbon-water interactions, and the up-scaling of ecosystem fluxes to regional and global scales.