1. Department of Life Sciences, Imperial College London, Silwood Park, Ascot, Berkshire, SL5 7PY, UK
2. Royal Botanic Gardens, Kew, Richmond, UK
3. Mathematics, Tampere University, Korkeakoulunkatu 7, FI-33720 Tampere, Finland
4. Hyytiälä Forestry Field Station, Faculty of Agriculture and Forestry, University of Helsinki, Hyytiäläntie 124, FI-35500 Korkeakoski, Finland
5. Natural Resources Institute Finland, Latokartanontie 9, 00790 Helsinki, Finland
6. Långstrandintie 281, 10600 Tammisaari, Finland