Old-growth forests inventory for British Columbia, Canada

We analyzed more than 7,000 1:20,000-scale forest cover maps for British Columbia to determine the amount of old-growth forest in the Canadian province. For this exercise, "old growth" was defined as: forests on the coast > 250 years old; and forests in the interior > 140 years old for most tree species, and > 120 years old for lodgepole pine and deciduous species. Using this definition, British Columbia is 37.1% nonforest, 36.1% younger forest, and 26.8% old growth. These data were analyzed by broad ecological (biogeoclimatic) zones. Old-growth forests cover more than 40% of the land base on the coast and at subalpine elevations in interior British Columbia, and less than 1% of the land base in the coastal rainshadow forests of southeastern Vancouver Island and the Gulf Islands. Approximately 7.7% of the province's land base is covered with forests > 250 years old. Almost 13% of British Columbia's remaining old growth is in protected areas. In the future, at ea of old-growth forest will decrease on the province's timber-harvest land base; this decrease may be somewhat offset by increases (due to fire suppression) outside of the timber-harvest land base.