Potential Alteration by Climate Change of the Forest-Fire Regime in the Boreal Forest of Central Yukon Territory

Abstract

Statistical relations were obtained to describe the association between forest fires and climate for the Dawson and Mayo fire management districts, central Yukon Territory. Annual fire incidence, area burned, and seasonal fire severity rating were compared with summer observations of mean temperature, total precipitation, mean relative humidity, and mean wind speed. The relations were obtained by multiple regression and combined with regional scenarios of future climate from general circulation models. The strongest statistical associations for fire occurrence and area burned were with temperature and precipitation at Dawson. Depending on the scenario, the statistics suggest that the average annual fire occurrence and area burned may as much as double by 2069, but there may still be years with few fires. The maximum number of fires may increase by two-thirds over present levels, and the maximum area burned per summer may increase to more than three times the present value. Without incorporating changes in climate variability into the scenarios, the year-to-year variability in number of fires is not projected to increase, but the range in area burned per summer may rise by about 15%.