1. Key Laboratory of Dryland Agriculture; Ministry of Agriculture; Institute of Environment and Sustainable Development in Agriculture; Chinese Academy of Agricultural Sciences; Beijing China
2. Key Laboratory of Forest Ecology and Environment; State Forestry Administration; Institute of Forest Ecology, Environment and Protection; Chinese Academy of Forestry; Beijing China
3. Key Laboratory of Ecosystem Network Observation and Modeling; Institute of Geographical Sciences and Natural Resources Research; Chinese Academy of Sciences; Beijing China
4. Department of Plant and Soil Sciences; College of Agriculture, Food and Environment; University of Kentucky; Lexington KY USA