A strategic assessment of crown fire hazard in Montana: Potential effectiveness and costs of hazard reduction treatments

Estimates of crown fire hazard are presented for existing forest conditions in Montana by density class, structural class, forest type, and landownership. Three hazard reduction treatments were evaluated for their effectiveness in treating historically fire-adapted forests (ponderosa pine (Pinus ponderosa Dougl. ex Laws.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), dry mixed conifer) that rate high/moderate for fire hazard. Comprehensive restoration treatments that address density, structure, and species composition of high-hazard forests are significantly more effective at reducing hazard than thin-from-below approaches that remove smaller trees only. Trees removed as a byproduct of the restoration treatment yielded net revenues averaging over $600 per acre, whereas the thin-from-below approach would require an out-of-pocket expenditure of over $600 per acre. Post-treatment conditions were projected forward 30 years and reevaluated for hazard. Projections revealed that effectiveness of all treatments diminished over time; however, forests receiving the comprehensive restoration treatment remained substantially lower hazard 30 years after treatment than they would have had they received the alternative treatments.