1. School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2. The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, United States
3. School of Geographic Sciences, East China Normal University, Shanghai 200241, China
4. Amsterdam Institute for Life and Environment (A-LIFE), Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HZ, The Netherlands