Silviculture and Wildlife: Snowshoe Hare Abundance across a Successional Sequence of Natural and Intensively Managed Forests

We tested the hypotheses H1 that relative habitat use by snowshoe hares (Lepus americanus) would have a bimodal distribution with the highest abundance in young lodgepole pine (Pinus contorta) stands (both managed and unmanaged), minimal numbers in mature forests, and moderate abundance in old-growth forests and H2 that habitat use would increase in response to enhanced stand attributes from PCT (precommercial thinning) and fertilization treatments. Habitat use was measured by counts of fecal pellets of hares from 1999 to 2003 in forest stands in south-central British Columbia, Canada. Our results did not support the bimodal distribution of hares among coniferous stands, such that old-growth stands, at least in our region, do not provide sufficient habitat for hare populations. High-density (5000 to 13000 stems/ha) unthinned young lodgepole pine stands provide optimum habitat for hares in terms of overstory and stand structure. Thinned and fertilized stands may also provide habitat, particularly at densities ≤1000 stems/ha, and over time as understory conifers develop. Managed stands provided habitat for hares at the same level as mature stands, at 6–10 years after PCT. Maintenance of a range of managed and unmanaged stands in a landscape mosaic would be ideal for integration of silvicultural and wildlife management goals. 1. Introduction The snowshoe hare (Lepus americanus) is distributed across the boreal, subboreal, and western montane forests of North America [1]. This leporid has a 9- to 11-year fluctuation in abundance and is the main prey for many vertebrate predators in these forests, such as Canada lynx (Lynx canadensis), coyotes (Canis latrans), fisher (Martes pennanti), and great horned owls (Bubo virginianus) [2, 3]. As such, the snowshoe hare is considered to be a keystone species in these forest ecosystems [4, 5]. The importance of hares, as a principal prey species, for conservation of lynx in the Pacific Northwest (PNW) has generated considerable recent interest in managing forest habitats for them [6–8]. Densely stocked stands of pine (Pinus spp.), spruce (Picea spp.), or deciduous species, usually 15 to 30 years after disturbance, provide the necessary food and cover that support hare populations [9, 10]. Heavy cover provided by understory herbs, shrubs, and lateral branches in or near dense stands is essential for predator avoidance [11, 12]. However, some early seral stages providing forage are required nearby and contribute to the shift in hares from relatively “open” habitats that have abundant herbaceous vegetation in summer to