The Department of Environmental Science Policy and Management (ESPM) in the College of Natural Resources:  Because I am primarily an ecologist, I also spend much of my time interacting with faculty and students from this department.  My primary advisor, Dr. John Harte, has a joint appointment between ERG and ESPM, Harte Lab Web Site.  John's main research interests include ecosystem-climate interactions and feedbacks, biodiversity conservation, biogeochemical cycling, macro-ecology and environmental modeling.  Much of his global change research in the past 15 years has focused around a meadow warming experiment at the Rocky Mountain Biological Laboratory (RMBL), in Gothic, Colorado.

I also work closely with Dr. Dennis Baldocchi and members of his lab group from the department of ESPM.  Dennis is a biometeorologist.  His research focuses on trace gas and energy fluxes between the biosphere and atmosphere. Dennis has two Ameriflux sites in California's Central Valley, where he is using the eddy covariance method to measure trace grass exchange in an oak savannah and an annual grassland: Baldocchi Lab Home Page. He will also begin a methane flux observational study in California's San Joaquin Delta later this year.

Thesis Research

         The objective of my thesis research is to explore the impacts of changes in California grassland species on global climate change. State-wide, grassland ecosystems in California have changed dramatically since pre-European settlement, from primarily native perennial grasses to dominance by annual grasses from Mediterranean Europe. We seek to understand how this grassland shift has affected climate change via changes in ecosystem carbon storage and flux and changes in the surface energy balance and albedo.
        To address these questions, we have set up a comparitive observational study at two locations in Marin County, California, where native perennial and exotic annual grasses grow in relative proximity on the same soils and slopes. One site is in the Golden Gate National Recreation Area (GGNRA) in the headlands above Tennessee Valley. The second is at the Bolinas Lagoon Preserve.  
         To date, we have collected two years of data documenting above and belowground plant productivity and conducted litter and root decomposition experiments in plots in each grass community.   Our aim is to uncover the mechanisms that govern differences in carbon storage and cycling between native perennial and exotic annual grass communities. In each plot, we also measure soil temperature and soil moisture at several depths and at the ground surface.
         At the Tennessee Valley field site, we have also been measuring the components of the surface energy balance and several additional micro-meteorological processes in each grass community.  Over the last year and a half, we have documented these processes using both the surface renewal and the eddy covariance methods.

         
 

Last Updated ~ January 9, 2006