1. School of Forestry, Beijing Forestry University, Tsinghua East Road, Haidian District, Beijing 100083, China
2. School of Ecology and Nature Conservation, Beijing Forestry University, Tsinghua East Road, Haidian District, Beijing 100083, China
3. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China