Associate Professor
Biology and Environmental Studies Program

B.A., English, with Highest Honors, University of Maine, Orono, 1980
B.A., Zoology, with Highest Honors, University of Maine, Orono, 1982
M.S., Ecology, University of Minnesota, 1986
Ph.D., Wetland Ecology, Duke University, 1991

Member of:
Center for Ecology and Evolutionary Biology

My diverse research interests are united under the central theme of understanding mechanisms controlling ecosystem structure and function. While I am interested in fundamental ecological questions, much of my work also has strong applied aspects. The scale of my research ranges from detailed examination of biogeochemical pathways and microbial dynamics, to plant community studies, to whole-watershed and landscape studies.

Questions that I focus on include:

• What are the underlying controls over rates of carbon and nutrient cycling, and how do anthropogenic perturbations interact with these underlying controls? I am particularly interested in rates under anaerobic conditions and factors that control the emission of methane, a potent greenhouse gas.
• How do plant and microbial community structure relate to rates of carbon and nutrient cycling? My recent research has particularly focused on (i) plant nutrient use efficiency, (ii) the role of invasive, exotic plants on ecosystem function, and (iii) the role of microbial community structure in soil carbon cycling.
• Can ecosystems be restored to provide similar functions as natural ecosystems, and what is the role of plant community structure and succession in achieving successful restorations?
• Climate change is a pervasive, on-going anthropogenic perturbation of natural ecosystems. How will it impact carbon and nutrient cycling, and what is the role of plant and microbial community structure in mediating these impacts?

Before coming to UO, my research was mostly in wetlands, and particularly in peatlands. While I continue to work in wetlands, my research in recent years has been extended to lakes, streams and rivers, whole-watersheds, upland prairies, savannas, and forests. However, the methods and questions that drive my research have remained fairly consistent in these different habitat types.

Click on any items below for more information:

 (i) Interactive Effects of Climate Change, Wetlands, and Dissolved Organic Matter on UV Damage to Aquatic Foodwebs
(ii) Manipulative Climate Change Experiment on Peatlands in Minnesota
(iii) Global Change Feedbacks on Trace  Gas Fluxes in Wetlands
(iv) A Carbon Budget for North American Wetlands
(v) Nutrient Dynamics in Wetlands
(vi) Soluble Organic Nutrient Dynamics in Terrestrial Ecosystems during Primary Succession
(vii) The Role of Edaphic Factors in Determining Plant Community Structure in Upland Prairies in the Pacific Northwest
(viii) Wetland Restoration
(ix)The Effects of Invasive Grasses on Ecosystem Function of a Freshwater Marsh and Estuarine Marsh
(x) Oak Savanna Successional Dynamics and Restoration