1. Global Change and Conservation Group, Helsinki Institute of Sustainability Science, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 65 (Viikinkaari 1) FI-00014 Helsinki, Finland
2. Tvärminne Zoological Station, University of Helsinki, J. A. Palménin tie 260, FI 10900 Hanko, Finland
3. Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI 00014 Helsinki, Finland