Fire history and ecology of remnant forest patches in the Sub-Boreal Pine-Spruce zone of central British Columbia

When a fire burns a substantial area of forest, it often leaves patches unburned. No published study appears to have addressed the question of whether or not there are patches that have never been burned by fires within the last few hundred years in British Columbia. Published studies have only partially addressed the question of whether or not there are some landscape factors that prevented fire from killing trees within the unburned patches. To address these questions, a project commenced in 1999 in the SBPSxc biogeoclimatic subzone with 2 main objectives - to determine (1) if there are some forest patches within lodgepole pine forests in this subzone in central B.C. that have not burned during the last 200-300 years, and (2) if forest patches within these lodgepole pine forests that did not burn at the time when the surrounding forests were most recently burned, have some characteristics that caused them not to burn. It was determined that in 24 of 26 patches studied, the most recent fire within the patch was the same one that established the surrounding forest. All patches had burned within the last 200-300 years. It is not completely certain why trees in the study patches escaped being killed during the fire that established the surrounding forest. It appears that lower tree density and basal area within the patches at the time of the fire may have been important. Other factors such as topographic features, soil moisture, and crown fuels do not appear to have been important.