James R. Ehleringer is a Distinguished Professor of Biology at the University of Utah. Throughout his career, Jim's research has focused on the ecology and ecophysiology of plants in arid, semi-arid, and forest ecosystems. His contributions have included photosynthesis, water relations, and stable isotopes. Jim's focus on stable isotopes has revealed the utility of this measurement as a natural recorder and tracer in both plants and animals on a spatial and temporal basis for improving our understanding of processes ranging from physiological through global scales.

Russell K. Monson is Professor Emeritus of Distinction in the Department of Ecology and Evolutionary Biology at the University of Colorado. Russ's research has focused on the evolutionary ecology of C4 photosynthesis, the nitrogen cycle in alpine ecosystems, carbon cycling in forest ecosystems, the reconstruction of climate patterns using tree ring stable isotopes, and the biochemistry and ecology of plant volatile compounds. Russ recently retired from a second career, serving as Louise Foucar Marshall Professor in the Department of Ecology and Evolutionary Biology and Laboratory for Tree Ring Research at the University of Arizona.