1. College of Urban and Environmental Sciences; Peking University; Yiheyuan Road 5 100871 Beijing China
2. Department of Biology; Centre of Excellence PLECO (Plant and Vegetation Ecology); University of Antwerp; Universiteitsplein 1 B-2610 Wilrijk Belgium
3. Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Center for Excellence in Tibetan Earth Science; Chinese Academy of Sciences; Beijing 100085 China
4. Institute of Geography; University of Neuchatel; Neuchatel Switzerland
5. Snow and Landscape Research; WSL Swiss Federal Institute for Forest; Neuchatel Switzerland
6. Group Mountain Ecosystems; WSL Institute for Snow and Avalanche Research SLF; Davos Switzerland
7. Max Planck Institute for Biogeochemistry; Hans Knöll Strasse 10 07745 Jena Germany
8. Department of Biosciences; University of Helsinki; Biocenter 3 FIN-00014 Helsinki Finland