1. International Institute for Earth System Science, Nanjing University, Nanjing 210093, China
2. State Key Laboratory of Subtropical Forest Science & Zhejiang Provincial Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration, Zhejiang Agriculture and Forestry University, Hangzhou, 311300 Zhejiang, China
3. Western Geographic Science Center, US Geological Survey, Menlo Park, CA 94025-3561, USA