1. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du PEPS, P.O. Box 10380, Québec, QC, G1V 4C7 Canada
2. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du PEPS, P.O. Box 10380, Québec, QC, G1V 4C7 Canada; Centre d’étude de la forêt, Université Laval, Québec, QC, G1K 7P4 Canada
3. Ruhr-Universität Bochum, Biodiversität und Evolution der Pflanzen, Geobotanik, Universitätsstraße 150, 44801 Bochum, Germany
4. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du PEPS, P.O. Box 10380, Québec, QC, G1V 4C7 Canada, and Department of Forest Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4 Canada