1. Department of Land, Air and Water Resources, University of California, Davis, Davis, CA 95616, USA.
2. CAS Key Laboratory of Forest and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
3. School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
4. John Muir Institute of the Environment, University of California, Davis, Davis, CA 95616, USA.