Ph.D. Indiana University, 1980

W. K. Kellogg Biological Station and
Department of Crop and Soil Sciences
Michigan State University
Hickory Corners, MI 49060
Phone: (269) 671-2267; Fax: (269) 671-2351
Email: robertson@kbs.msu.edu

Research Interests

Research in my lab falls under the general heading of terrestrial biogeochemistry, with a particular emphasis on processes that regulate nutrient availability in agricultural and other disturbed ecosystems. Currently my group's research centers on (1) biogenic trace gas fluxes in terrestrial ecosystems as a function of land use and management, (2) the spatial heterogeneity of nutrient availability in native and managed landscapes, and (3) process-level controls on nitrogen availability.

• Trace gas fluxes -- in particular fluxes of nitrous oxide and methane -- are important contributors to global warming, but their biological sources and sinks are poorly understood; our research is aimed toward understanding the processes controlling these fluxes at the ecosystem level.
• Spatial heterogeneity is an implicit feature of all ecological phenomena; our interests here center on applying new mathematical approaches to studies of the distribution of soil nutrients and microbes in terrestrial landscapes; these approaches should be useful for highlighting potential controls on processes at different scales.
• Our investigations of nitrogen availability include examining relationships among soil microbial and invertebrate activity, root uptake and turnover, and soil biological processes and controls on nitrogen loss. Of particular interest are nitrate and dissolved organic nitrogen leaching, denitrification, and the relationship between nitrogen cycle processes and soil microbial diversity.

Underlying all work in my lab is the general aim of understanding the processes that regulate biogeochemical cycles at scales ranging from the microbial to the global.