1. Natural Resources Institute Finland (Luke), Helsinki, Finland
2. Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), Alnarp, Sweden
3. Natural Resources Institute Finland (Luke), Savonlinna, Finland
4. Natural Resources Institute Finland (Luke), Joensuu, Finland
5. Department of Forest Resource Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
6. Instituto de Ciencias Forestales ICIFOR-INIA, Madrid, Spain