I am a Professor of Pedology at the University of California, Berkeley. 



Soils and Environmental Change

I am especially interested in feedbacks between soil carbon/nitrogen and global climate. 

South Dakota State University

BS Soil Science

Soil and Earth History

We use the latest geochemical and isotopic techniques to use carbonate minerals in soils to provide high resolution paleoenvironmental reconstructions over the past several million years of Earth history. 

Humans and the Global Landscape

The face of the planet, and its soil cover, has been transformed in a few thousand years by humans. What are the effects of these changes on geobiodiversity and climate. I am also interested in ways that land use can be both intensified and stabilized in order to reduce or stem the conversion of additional ecosystems. 

The Biogeochemistry of Earth Deserts and Mars

The landscapes that much of my research focuses on are deserts. These are attractive because these are the edges of life on Earth, and allow us to better understand the mechanisms and roles that biology plays in global stability. These are also the places on Earth most similar to Mars, and allow us to re-evaluate recent Mars data in terms of what it tells use about that planet's history. 

University of California 


MS Soil Science

University of California


PhD Soil Science