[1] Univ British Columbia, Dept Forest Resources Management, Fac Forestry, Vancouver, BC V6T 1Z4, Canada
[2] Univ British Columbia, Dept Forest Sci, Fac Forestry, Vancouver, BC V6T 1Z4, Canada
[3] Univ British Columbia, Ctr Appl Conservat Res, Fac Forestry, Vancouver, BC V6T 1Z4, Canada
[4] British Columbia Minist Forests & Range, Nanaimo, BC V9T 6E9, Canada