1 Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China.
2 State Key Laboratory of Grassland Agro- Ecosystems, Institute of Innovation Ecology and School of Life Sciences, Lanzhou University, Lanzhou, China.
3 CAS Key Laboratory for Plant Diversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.