1. School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, 100083, China
2. School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
3. Ganzi Institute of Forestry Research, Sichuan, 626001, China
4. Tibet Museum of Natural Science, Science and Technology Department of Tibet, Tibet Lhasa, 850000, China