1. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, P.O. Box 10380 Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada.
2. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada.
3. Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, 5320-122nd Street, Edmonton, AB T6H 3S5, Canada.