1. Department of Geography University of Nevada, Reno 1664 North Virginia Street Reno Nevada 89557 USA
2. Department of Natural Resources and Environmental Science University of Nevada, Reno 1664 North Virginia Street Reno Nevada 89557 USA
3. U.S. Geological Survey, Western Ecological Research Center 160 North Stephanie Street Henderson Nevada 89074 USA
4. U.S. Geological Survey, Western Ecological Research Center 4165 Spruance Road Suite 200 San Diego California 92101 USA