1. Dept of Ecology and Genetics, Univ. of Oulu; Finland
2. Finnish Wildlife Agency, Oulu Regional Office; Muhos Finland
3. Island Ecology and Biogeography Research Group, Dept of Botany, Ecology and Plant Physiology, Faculty of Sciences, Univ. of La Laguna; La Laguna St Cruz de Tenerife Spain
4. Faculty 02 (Biology/Chemistry), Bremen Univ; Bremen Germany