Estimating postfire survival of Douglas-fir in the Cascade Range

Abstract

Factors related to survival of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) 2 years after spring wildfires were evaluated at four sites in the Cascade Range. A logistic regression model was developed to estimate postfire survival. Crown scorch and three variables related to bole damage were significant in the regression model, with differences in response among sites attributed to differences in size class. The regression model predicted postfire response of live trees more accurately than that of dead trees, based on estimates of survival probability. Crown scorch was the most significant predictor of tree response, although the importance of additional variables indicated that evaluating bole damage greatly improves postfire survival estimates.