1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water ConservationNorthwest A&F University Yangling Shaanxi 712100 PR China
2. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco‐Environmental SciencesChinese Academy of Sciences Beijing 100085 PR China
3. University of Chinese Academy of Sciences Beijing 100049 PR China
4. Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences Chengdu Sichuan 610041 PR China
5. School of Geography and TourismShaanxi Normal University Xi'an Shaanxi 710119 PR China