Initial Effects of Clearcutting and Partial Retention Forest Harvesting Methods on Some Small Mammals in Northern British Columbia

British Columbia’s interior forests have been heavily subjected to logging, burning, and beetle outbreaks for decades. Partial retention forest harvesting may be a method that could mitigate some of the negative effects of clearcut harvesting on wildlife. We conducted live trapping for small mammals at John Prince Research Forest in north-central BC to estimate species diversity, population density, and habitat use across a gradient of overstory tree retention. We detected 7 species, with diversity highest in the uncut forest (control) relative to the clearcut (control mean Shannon Index = 1.01, SE = 0.14) and partial retention treatments (30% and 60% retention, mean Shannon Indices = 0.99, 0.98; SE = 0.17, 0.17), and significantly lower in the seed tree treatment (mean = 0.63, SE = 0.17, p = 0.02). Greater population densities of North American deer mouse (Peromyscus sonoriensis) and southern red-backed vole (Myodes gapperi) in partially harvested stands, as estimated with spatially explicit capture-recapture models, support these practices for supporting populations of forest specialists. More experimental approaches to forest operations are needed across larger spatial scales, such as adaptive management of forest harvest methods with rigorous wildlife monitoring to ensure ecological objectives are met.