1. Department of Environmental Studies, University of Colorado Boulder, Boulder, Colorado 80303, United States
2. Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado 80303, United States
3. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
4. Department of Environmental Toxicology, University of California Davis, Davis, California 95616, United States
5. National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
6. Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523, United States
7. Department of Integrative Biology, University of California Berkeley, Berkeley, California 94720, United States
8. Department of Environmental Science, Policy & Management, University of California Berkeley, Berkeley, California 94720, United States
9. Center for Stable Isotope Biogeochemistry, University of California Berkeley, Berkeley, California 94720, United States