The areal pattern of burned tree vegetation in the subarctic region of northwestern Canada

Abstract

In terms of its lower areal extent of burns, and lower frequency of air photos showing burns, the forest-tundra is distinct from both open crown and closed crown forest regions. Burns show a general decrease in areal coverage from NW (Mackenzie River to Great Bear Lake: 0-50% of the terrain) to SE (Great Slave Lake to Hudson Bay: 0-10%). In the NW, the flat till plains, high cover of continuous mature forest, and scarcity of lakes, coupled with dominance of slowly regenerating white spruce Picea glauca (in the forest-tundra) may help to account for the extensive burned vegetation. In the E half of the study region, the northern limit of burns normally does not extend beyond the line where tree cover equals upland tundra cover. In this E sub-region, tree cover decreases rapidly northward within the southern half of the forest-tundra, constraining the areal extent of individual burns. -from Authors