PhD Graduate Assistantships are available at the University of Wyoming to study ecosystem responses in a state-of-the-art multi-factor experiment in native grassland involving warming, elevated carbon dioxide, precipitation enhancement and invasive species introduction. Interactions among these global change drivers affecting carbon and water cycling, competitive interactions, and belowground resource availability are poorly understood. Successful candidates will be ambitious and energetic students interested in applying stable isotope techniques to field experiments, demonstrate excellent communication skills, and possess a MS degree in biology, ecology, soil science or a related field. Students may choose among several PhD degree programs including Ecology, Botany, and Rangeland Ecology. Inquiries should be made to Dr. Elise Pendall ([log in to unmask]; http://www.uwyo.edu/terra/) or Dr. David Williams ([log in to unmask]; http://www.uwyo.edu/dgw/index.html). Applications are due by Jan. 31, 2007, and positions may start as early as May, 2007. The University of Wyoming is an EEO/AA Employer.