Haiyan Wei, Tucson, AZ, United States, David C Goodrich, Agricultural Research Service, Tucson, AZ, United States, Mark Nearing, USDA ARS, Tucson, AZ, United States, D. Phillip Guertin, USDA-ARS Southwest Watershed Research Center, Tucson, AZ, United States and Philip Heilman, USDA-ARS Southwest Watershed Research Center, Tucson, United States