1. Department of Resource and Environmental Science; Wuhan University; Road Luoyu 129 Wuhan China
2. Department of Physical Geography and Ecosystem Science; Lund University; Sölvegatan 12 SE-223 62 Lund Sweden
3. Department of Forest Ecosystems and Society; Oregon State University; Corvallis OR 97331 USA
4. Department of Geography; University of Sheffield; Winter Street, Sheffield S10 2TN Sheffield UK
5. Royal Swedish Academy of Sciences; Lilla Frescativägen 4A 114 18 Stockholm Sweden
6. Department of Animal and Plant Sciences; University of Sheffield; S10 2TN Sheffield UK