r e s e a r c h.. p r o g r a m . o v e r v i e w

I study factors that regulate the structure, species composition, biodiversity, and energy and nutrient metabolisms interrestrial ecosystems. The primary focus of my research since 1988 has been the effects of grazing ungulates, such as elk, bison, and pronghorn, on grassland of Yellowstone National Park. Yellowstone grassland represents highly coevolved plant-grazer-soil microbe systems. My lab investigates important interactions among these interacting trophic levels that facilitate energy and nutrient flows in Yellowstone grassland and foster stability of this ecosystem that experiences high chronic levels of grazing.

My research includes both field and laboratory experiments. In the field, weerect ungulate exclosures to create an ungrazed treatment; then we compare plant growth and soil processes in grazed vs ungrazed grassland. In the lab, we focus on specific mechanisms that may drive results observed in the field. Experiments are conducted in the greenhouse or in environmental chambers to determine how mycorrhizae, nutrient availability, and soil microbial composition and diversity may mediate the effect that grazing has on plant growth.

For more details about my research and related publications, please select from the following:

• The sustainability of grazing ecosystems
• Soil microbial biodiversity

Undergraduate students: Please click here for information about research opportunities in my lab.