Role of vegetation and weather on fire behavior in the Canadian mixedwood boreal forest using two fire behavior prediction systems

Spring and summer simulations were carried out using the Canadian Fire Beha vior Prediction (FBP) and U.S. BEHAVE systems to study the role of vegetati on and weather on fire behavior in the mixedwood boreal forest. Stands at L ake Duparquet (Quebec, Canada) were characterized as being deciduous, mixed -deciduous, mixed-coniferous, or coniferous, according to their conifer bas al area percentage. Sampled fuel loads (litter, duff, woody debris, herbs, and shrubs) and local weather conditions (three different fire-risk classes ) were used as inputs in the simulation. The predicted fire behavior variab les were rate of spread (ROS), head fire intensity (HFI), and area burned. Results from ANOVA testing showed that both weather and vegetation are not always significant, and the two prediction systems qualitatively attribute the explained variance to these factors differently. The FBP System selects the weather factor as the most important factor for all fire behavior vari ables, whereas BEHAVE selects the vegetation factor. However, three researc h burns located in Ontario revealed that BEHAVE was not well adapted to the mixedwood boreal region, whereas FBP predictions were quantitatively close to observed prescribed values. Extreme fire weather is confirmed as produc ing large and intense fires, but differences in fire behavior among stand t ypes exist across the full range of fire weather. Implications of climate c hange, vegetation, and seasonal effects on fire behavior and the forest mos aic are discussed.