Modeling the Influence of Forest Structure on Microsite Habitat Use by Snowshoe Hares

Abstract

Snowshoe hare ( Lepus americanus ) is an important prey species for many Carnivora and has strong influences on community structure and function in northern forests. An understanding of within-stand (microsite) forest structural characteristics that promote high use by hares is important to provide forest management guidelines. We measured forest structural characteristics at the microsite-scale in north-central Maine and used an information-theoretic modeling approach to infer which characteristics were most strongly associated with use by hares during winter. We measured overwinter hare pellet density to model relationships among microsite-scale vegetation structure and hare use. Overwinter pellet density was positively associated with live stem cover (3 × coniferous saplings + deciduous saplings) and negatively associated with overstory canopy closure; the two variables explained 71% of the variation in microsite use by hares. The highest pellet densities were in grids with canopy closure <72% and stem cover units >22,000 stems/ha. Silvicultural practices that create dense areas of conifer and deciduous saplings should receive high within-stand use by hares in winter. These conditions can be achieved by promoting the release of advanced regeneration and reducing overstory cover to encourage establishment of shade-intolerant species; clearcutting is one such silvicultural prescription to achieve these conditions.