About Our Research

Our research program focuses on studying: ‘the physical, biological and chemical processes that govern trace gas and energy exchange between the terrestrial biosphere and the atmosphere’.  In layman terms, our broad objective is to understand how the terrestrial biosphere ‘breathes’; plants and microbes exchange trace gases, in and out of the atmosphere, in their quest to acquire the energy needed to support their metabolism. 

We use California as a natural laboratory for this work as its Mediterranean type climate experiences a wide range in temperature, rainfall and soil moisture.  For example, over a year the weather in northern California experiences distinct cool, wet and hot, dry, sunny periods.  We also get up to plus/minus 30% year to year variability in rainfall.

Our flux measurements are made across a mesonetwork of natural and managed field sites across northern California. Our field sites cover a wide range of structure and function, in order to understand how ecosystem metabolism is responding to weather and climatic fluctuations and trends.  

Our field sites include set of semi-arid native vegetation, a selection of agricultural crops and a set of tidal and non tidal restored wetlands. The native vegetation include an oak savanna (Tonzi Ranch) and an annual grassland (Vaira Ranch) near Ione.  Agricultural crops include rice, pasture, corn, alfalfa, sorghum and wheat on Bouldin and Twitchell Islands.  The restored non tidal wetlands on Sherman and Twitchell Islands vary in age with the oldest planted in 1997 and others in the 2007 to 2013 time frame.  The restored tidal wetlands span a fresh to brackish salinity gradient across the San Francisco Bay Estuary (Dutch Slough and Hill Slough). We are founding and active members and contributors to the Ameriflux and Fluxnet networks and have contributed over 100 site years of data to the project.

Over the years our research has been funded by grants and contracts from the US Department of Energy's Office of Science, NASA, USDA, California Department of Water Resources, and Ducks Unlimited.

Information about each of our long term field sites is accessible in the Tab