1. Department of Environmental Sciences, Forest Ecology; Swiss Federal Institute of Technology, ETH Zurich; Universitätstrasse 16 CH-8092 Zürich Switzerland
2. Swiss Federal Institute for Forest, Snow and Landscape Research WSL; 8903 Birmensdorf Switzerland
3. Irstea-EMGR; 2 Rue de la Papeterie, BP 76 38402 Saint-Martin-d'Heres Cedex France
4. Institute of Silviculture; University of Natural Resources and Life Sciences, Vienna (BOKU); Peter-Jordan-Straße 82 1190 Vienna Austria
5. Department of Forestry and Renewable Forest Resources; Biotechnical Faculty; University of Ljubljana; Vecna Pot 83 1000 Ljubljana Slovenia
6. Department of Silviculture and Forest Systems Management; INIA-CIFOR; Crtra Coruña Km 7.5 28040 Madrid Spain