1. Department of Mathematics and Mathematical Statistics, Umeå University, Umeå, Sweden
2. Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden
3. Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, Umeå, Sweden
4. Ecosystems Services and Management Program, International Institute for Applied Systems Analysis, Laxenburg, Austria
5. Evolution and Ecology Program, International Institute for Applied Systems Analysis, Laxenburg, Austria