1. Department of Ecology and Evolutionary Biology, University of Michigan , Ann Arbor, MI 48103 , USA
2. Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, CA 94720 , USA
3. Department of Biology, University of Puerto Rico , Río Piedras, PR 00931 , USA
4. Department of Environmental Sciences, University of Puerto Rico , Río Piedras, PR 00936 , USA
5. Department of Biological Sciences, University of Notre Dame , South Bend, IN 46556 , USA
6. UK Centre for Ecology & Hydrology , Bush Estate, Penicuik, Midlothian EH26 0QB , UK
7. Department of Ecology, Evolution & Environmental Biology, Columbia University , New York, NY 10027 , USA