Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China;
Chongqing Key Laboratory of Earth Surface Processes and Environmental Remote Sensing in the Three Gorges Reservoir Area Chongqing 401331 China;
University of Chinese Academy of Sciences Beijing 100049 China;
Sustainable Agriculture Sciences Department Rothamsted Research North Wyke Okehampton Devon EX20 2SB UK;