Yao Lu^1,2, Yang Gao^1,2, Xuefa Wen^1,2, Nianpeng He^1,2, Junjie Jia^1,2 and Zhuo Hao^1,2, (1)Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China, (2)University of Chinese Academy of Sciences, Beijing, China