1. IERM, University of Edinburgh, King’s Buildings, Edinburgh, UK;
2. present address: School of Biological Science, University of New South Wales, UNSW Sydney 2052, Australia
3. Forestry Commission, Alice Holt Lodge, Farnham, Surrey, UK;
4. Department of Biology, University of Antwerpen, Wilrijk, Belgium;
5. DISAFRI, University of Tuscia, Viterbo, Italy;
6. Institut für Ökologie, Technische Universität Berlin, Germany;
7. Department of Economics and Natural Resources, Royal Veterinary and Agricultural University, Denmark;
8. Faculty of Forestry, University of Joensuu, Finland;
9. Department de Biologie Vegétalé, Faculte des Sciences Agronomiques de Gembloux, Belgium;
10. Department for Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden;
11. Agricultural Research Institute, Keldnaholt, Reykjavik, Iceland;
12. Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, USA;