1. Department of Forest Biology, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51014 Tartu, Estonia
2. Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands
3. Laboratory of Ecology and Systematics, Faculty of Science, University of Ryukyus, Nishihara, Okinawa 903-0213, Japan
4. Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland
5. Department of Ecophysiology, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Viljandi mnt. 18B, 11216 Tallinn, Estonia
6. Disturbance Ecology, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
7. Uryu Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Moshiri, Horokanai, Hokkaido 074-0741, Japan