Molecular interactions of the plant-soil-microbe continuum of bioenergy ecosystems

This research aims to reveal the microbial mechanisms that regulate carbon (C) stabilization in soils dedicated to biofuel crops, and test identified mechanisms in ecosystem-scale field experiments. Emerging evidence suggests that dead microbial biomass, or necromass, constitutes a significant fraction of soil organic matter. Although microbial necromass stabilization is frequently invoked as a mechanisms for long-term soil C storage, there remains limited empirical data illustrating the complement of molecules that comprise microbially derived soil organic C. I aim to evaluate the effect of bioenergy crops on the production of microbial necromass and the selective preservation of microbial necromass in two distinct bioenergy soils. I will quantify the microbial contribution to soil organic C accumulation under perennial (switchgrass) and annual (corn) biofuels in long-term experimental plots of the Great Lakes Bioenergy Research Center. Using a combination of model informed lab and field experiments, I will apply molecular approaches to identify dominant microbial metabolic pathways and quantify the extent to which their stable end products influence C cycling in bioenergy feedstock agroecosystems.