1. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec, QC G1V 4C7, Canada.
2. Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB T6H 3S5, Canada.
3. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC V8Z 1M5, Canada.
4. Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, Corner Brook, NL A2H 6J3, Canada.
5. Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, Victoria, BC V8Z 1M5, Canada.