I study the interactions between global climate change factors and the terrestrial biosphere, focusing on rising atmospheric carbon dioxide (CO2), crop and livestock agriculture, and the global carbon cycle. The responses of plants and soils to changing atmospheric chemistry and climate are still poorly understood, as is the role of recent agricultural expansion in disrupting global carbon and water cycles. I have looked at the effects of multiple global change factors on soil carbon, arbuscular mycorrhizal (AM) and other fungi, crop plants, weeds, and changes in plant qualities that may impact consumers such as bees, livestock, and people.
Because studies of CO2 and other climate change factors are often limited in extent and statistical power, I strive for higher replication and more studies--both experimental and observational, at greenhouse, growth chamber, field, and regional scales. I also use modeling and computation to work at regional and global scales. Because GHG emissions, climate, trade, and hunger are global phenomena, research to address these problems must also extend to global scales, and must consider both contributions and responses to perturbations in global carbon and water cycling.