Jeff joined ORNL in 2010 and investigates ecosystem response to climate change within the Environmental Sciences Division and the Climate Change Science Institute. He holds an Adjunct Faculty appointment with the Department of Forestry, Wildlife and Fisheries at the University of Tennessee-Knoxville. His background includes physics (B.S. - Miami University), Forest Science (M.S. - NC State University) and Tree Physiology (Ph.D. - Washington State University. Warren’s research interests include how ecosystems are impacted by changes in the environment, including consequent interactions within and across species and how cascading effects are exhibited at higher trophic and scalar levels. His research investigates how terrestrial ecosystems adapt to changes in the environment, including subtle or severe abiotic or biotic disturbances. Much of his work is focused on plant physiology and soil-plant water relations, and how key mechanistic processes can be better represented in, and scaled to terrestrial biosphere models.