1. Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA 95616
2. Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA 95616; Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
3. Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA 95616; USDA Forest Service, Pacific Southwest Region, 1323 Club Dive, Vallejo, CA 94592