Dissertation Research: Soil Aggregation and Ecosystem Function

Michigan State University, East Lansing MI

Investigators

Abstract

Soil aggregates, groups of soil particles bound together into a larger structural unit, may be important regulators of carbon and nitrogen cycling in soil. Aggregates physically protect organic matter from microbial oxidation and provide microsite habitats that may favor greenhouse gas production. Aggregate structure is typically lost following soil disturbances such as tillage, and the recovery of aggregate structure could help mitigate environmental problems related to carbon and nitrogen cycling. Accelerated carbon and nitrogen transformations in disturbed ecosystems contribute to a number of environmental problems, including greenhouse gas accumulation, groundwater contamination, and soil erosion. This research will examine soil aggregation and its effects on carbon and nitrogen cycling in ten ecosystems on the same soil series along a disturbance gradient. The systems range from intensively managed, row crop agriculture to late successional forests. The research will test hypotheses about the recovery and breakdown of aggregates on soil carbon storage, trace gas fluxes, and microbial population structure.