Affiliation: | 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, P. R. China;2. Qinghai Academy of Animal and Veterinary Sciences, Key Laboratory of Alpine Grassland Ecosystem in the Three River Head Waters Region Jointly Funded by Qinghai Province and Ministry of Education, Xining, Qinghai, P. R. China |