1. Irstea; UR Mountain Ecosystems; St-Martin-d'Hères France
2. CNRS UMR 6553, ECOBIO, Université de Rennes 1; Rennes France
3. Laboratoire d'Ecologie Alpine; CNRS UMR 5553; Université Joseph Fourier; Grenoble France
4. Department of Biology; McGill University; Montreal Quebec Canada
5. Department of Ecology and Evolutionary Biology; University of Arizona; Tucson AZ USA
6. Centre d'Ecologie Fonctionnelle et Evolutive; CNRS UMR 5175; Montpellier France
7. Department of Biological Sciences; Macquarie University; Sydney NSW 2109 Australia
8. Ecole Polytechnique Fédérale de Lausanne (EPFL); Laboratory of Ecological Systems (ECOS) - Swiss Federal Institute for Forest, Snow and Landscape Research (WSL); Research Group Restoration Ecology; Station 2 CH-1015 Lausanne Switzerland