1. Biodiversity and Landscape Unit; Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2; 5030 Gembloux Belgium
2. Chair of Restoration Ecology; Technical University of Munich, Emil-Ramann-Str. 6; 85354 Freising Germany
3. Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115; 1431 Ås Norway