My main research interests involve paleolimnology and phytoplankton ecology, as I use diatom fossil records in lake sediments to reconstruct environmental change over time. My approach differs from conventional reconstructions involving diatom profiles in that I apply information from both field observations and bioassays to the sediment records, and I use patterns in the sediment record to pose testable hypotheses about mechanisms driving observed changes. My current research in the Beartooth Mountain Range of the central Rocky Mountains focuses on understanding how the interactive effects of enhanced atmospheric nitrogen deposition and climate change may be driving observed shifts in alpine diatom communities. I also use algal ecology as a tool to investigate indirect lake-climate interactions, particularly the linkage between lake-water chemistry and climate, in saline lakes of the northern Great Plains.

Current Research

Climate-Induced Shifts in Alpine Diatom Communities: Linking Neoecological and Paleoecological Approaches to Incorporate Responses to Trophic Forcing

The Response of Lakes to Disturbance and Climate Change: Calibrating Sedimentary Records to Test the Landscape Position Concept

Mapping Critical Loads of Atmospheric N and S deposition in the Rocky Mountains

Interactive Effects of UV Radiation and Temperature on Pelagic Foodwebs

The Role of Dissolved Organic Material in Regulating Primary Production in Prairie Saline Lakes

Determining Critical Loads of Nitrogen Deposition in the Pacific Northwest