Salvage logging after an insect outbreak reduces occupancy by snowshoe hares (Lepus americanus) and their primary predators

Abstract

Abstract Salvage logging after a natural disturbance is controversial because it may disrupt forest succession and reduce the value of wildlife habitat, but few studies have examined consequences on predator-prey systems. For herbivores that consume early-seral vegetation, salvage logging may simultaneously improve food abundance and reduce protective cover, imposing trade-offs that influence their habitat selection and that of their predators. We examined habitat use by snowshoe hares (Lepus americanus)—a keystone prey species in the boreal forest—and their primary predators, Canada lynx (Lynx canadensis) and coyotes (Canis latrans), in response to salvage logging following a bark beetle outbreak in Yukon, Canada. We monitored hare, lynx, and coyote presence in beetle-affected forests and salvage-logged stands of different tree retention levels and ages (up to 25 years post-logging) using wildlife cameras, and modelled species occupancy as a function of forest structure at local and landscape scales. Snowshoe hares occupied stands with dense canopies and avoided salvage-logged stands regardless of retention class or age, selecting habitat with the most cover from aerial and terrestrial predators. Lynx and coyote generally used the same habitat as hares, selecting unsalvaged stands with high snowshoe hare occupancy. Habitat use by coyote and hare was more strongly linked than that of lynx and hare, perhaps because coyotes are versatile predators that can adjust their hunting tactics in dense habitat. Our study demonstrates that salvage-logged stands have lower value than beetle-affected forest for snowshoe hares and their predators in the short-term—regardless of retention levels—which may have localized impacts on boreal forest food webs. Higher tree retention, long harvest intervals, and small cut areas interspersed with large unlogged forest patches are recommended to mitigate negative impacts of salvage logging on these species.