1. State Key Laboratory of Soil Erosion and Dryland Farming in the Loess PlateauNorthwest A&F University Yangling 712100 PR China
2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Beijing 100101 PR China
3. College of Recourses and EnvironmentUniversity of Chinese Academy of Sciences Beijing 100049 PR China
4. Department of Soil, Water and ClimateUniversity of Minnesota St. Paul MN 55108 USA
5. College of Natural Resources and EnvironmentNorthwest A&F University Yangling 712100 PR China
6. CAS Center for Excellence in Quaternary Science and Global ChangeChinese Academy of Sciences Xi'an 710061 PR China
7. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences 818 South Beijing Road Urumqi 830011 PR China