Snow depth as a function of canopy cover and other site attributes in a forested ungulate winter range in southeast British Columbia

Abstract

Snow depth is considered a major influence on deer (Odocoileus spp.) winter distribution and abundance in northern parts of their range. Overstorey canopy cover is often considered a principal variable governing snow depths in forests and has implications for managers who wish to achieve reduced snow depths by manipulating canopy closure in forests. I used three years of snow-depth data collected in forested ungulate winter range in southeast British Columbia to determine the relative influence of canopy closure and other site attributes on snow depth. Although canopy closure was a major factor in determining snow depth, it was outweighed by elevation and aspect. I found a close relationship between canopy closure and snow depth at low-elevation sites, but this relationship diminished or disappeared at higher elevations and on cooler aspects supporting the hypothesis that the influence of canopy closure depends on overall snow accumulation. At low elevations, forest managers could use canopy closure to influence snow depths. I offer the generalization that, on similar sites, maintaining 50% canopy closure will reduce snow depths by approximately 20%; 100% canopy closure will reduce snow depths by up to 40%.