1. Division of Forestry and Forest Resources, Norwegian Institute of Bioeconomy Research, Ås, Norway
2. Institut Européen de la Forêt Cultivé, Cestas, France
3. Chair of Forestry Economics and Forest Planning, University of Freiburg, Freiburg, Germany
4. Norconsult, Dep. Kjeller Vindteknikk, Lillestrøm, Norway
5. Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway