Estimating stand-level economic impacts of black bear damage to intensively managed forests

Abstract

Black bears (Ursus americanus Pallas, 1780) peel conifers in early spring to forage on energy-rich vascular tissues, resulting in damage to timber stands. The objective of our study was to develop and demonstrate a conceptual framework and methods for estimating stand-level volume and economic losses from black bear damage. We created tree lists from surveys of healthy and bear-damaged trees in timber stands of western Washington and Oregon. The forest growth model Forest Vegetation Simulator (FVS) was used to project stand volume under two damage scenarios and an undamaged scenario. One damage scenario (salvage) accounted for mortality and volume losses of fully and partially girdled trees; a second scenario (total loss) assumed complete loss of all trees peeled by black bears, regardless of peeling severity. The Fuel Reduction Cost Simulator (FRCS) was applied to estimate the value of logs delivered to the mill after accounting for logging and hauling costs associated with harvest. Present value of stands was calculated to translate volume losses into economic losses associated with bear damage. Economic losses ranged from 4% to 16% (salvage) and from 17% to 46% (total loss) of net present value. Our approach can be adapted for other forest settings and for forest management plans that assess wildlife damage.