MODELING EFFECTS OF PRESCRIBED FIRE ON YOUNG-GROWTH COAST REDWOOD TREES

The study was designed to produce data for modeling effects of prescribed fire treatments on top killing and basal sprouting of coast redwood trees (Sequoia sempervirens (D. Don) Endl.) at the plot and individual-tree level. Prescribed fire treatments included two levels of fireline intensity and surface fuel consumption crossed in randomized blocks. Burning was conducted on 32 plots each containing approximately 150 to 250 redwoods. Binary responses of individual trees were modeled using logistic regression analysis. Percent response of trees on each plot by 5-cm diameter classes was modeled using logistic and nonlinear regression analysis. Tree diameter, surface fuel consumption, flame length, and crown scorch were significant predictors in all models of top killing and basal sprouting. Models relating heights of crown scorch and bark charring to fire and tree characteristics were also developed. The ability of coast redwood to sprout along branches following foliar damage from fire is unusual among conifers and contributes to a low incidence of top killing.