1. State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China
2. Zigui Three Gorges Reservoir Ecosystem, Observation and Research Station of Ministry of Water Resources of the People’s Republic of China, Yichang 443605, China
3. College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
4. Ecosystems and Global Change Group, School of the Environment, Trent University, Peterborough, Ontario K9L 0G2, Canada
5. Ecosystems and Global Change Group, Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, U.K.