1. School of Economics and Management, Beijing Forestry University, Beijing 100083, China
2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
3. United Nations Environment Programme-International Ecosystem Management Partnership (UNEP-IEMP), Beijing 100101, China
4. Department of Applied Biology, Technical University of Kenya, Nairobi P.O. Box 52428-00200, Kenya