1. Forest Biodiversity Research Network, Department of Forest Ecosystems and Society Oregon State University 3100 SW Jefferson Way Corvallis OR 97331 U.S.A.
2. Center for Macroecology, Evolution and Climate GLOBE Institute, University of Copenhagen Universitetsparken 15 Copenhagen Ø 2100 Denmark
3. Department of Life Sciences Imperial College London Silwood Park, Buckhurst Road, Ascot Berkshire SL5 7PY U.K.