1. The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, China.
2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China.
3. University of Chinese Academy of Sciences, Beijing, China.
4. School of Forestry, Northern Arizona University, Flagstaff, AZ, USA.
5. Center of Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
6. Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Seville, Spain.
7. Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture and Rural Affairs/College of Land Science and Technology, China Agricultural University, Beijing, China.