Affiliation: | 1.Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland ;2.Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Helsinki, Finland ;3.Department of Applied Biology, HAS University of Applied Sciences, Onderwijsboulevard 221, 5223 DE, ‘s-Hertogenbosch, The Netherlands ;4.Lammi Biological Station, University of Helsinki, P??j?rventie 320, 16900, Lammi, Finland ; |