Modeling Pinus strobus mortality following prescribed fire in Quetico Provincial Park, northwestern Ontario

In forest ecosystems where ecologically beneficial fire impacts are promoted through the use of prescribed fire, predictive models of fire effects, such as tree mortality, are essential for assessing the ecological consequences of fire management options. Impact of tree size, fire intensity, and fuel characteristics on postfire eastern white pine (Pinus strobus L.) mortality was evaluated 10 months following a prescribed fire in Quetico Provincial Park, northwestern Ontario. A logistic regression model was developed to predict white pine mortality following an intense surface fire (1200 kW/m). Overall fire-caused mortality was relatively low (17.0%). Probability of mortality increased with increasing height of stem blackening, a surrogate measure of fire intensity, and decreased with increasing tree diameter at 1.3 m (DBH). White pine with greater than or equal to20 cm DBH were found to be highly resistant to intense surface fire. The model can be used to predict postfire mortality in white pine stands with a mixedwood understory in the Great Lakes - St. Lawrence forest region of Ontario.