Stefan Ploum, SLU Swedish University of Agricultural Sciences Umea, Umeå, Sweden, Lenka Kuglerová, SLU Swedish University of Agricultural Sciences Umea, Umea, Sweden, Jason Leach, Canadian Forest Service, Sault Ste Marie, ON, Canada and Hjalmar Laudon, SLU Swedish University of Agricultural Sciences Umeå, Umeå, Sweden