Aim The goal of this study was to evaluate the sufficiency of the network of protected lands in the U.S. northern Rocky Mountains in providing protection for habitat connectivity for 105 hypothetical organisms. A large proportion of the landscape falls into one of several categories of protected lands. However, protected lands in the region are primarily higher elevation forest and mountain habitats. Little is known about how the network of protected lands may maintain connectivity for a broad spectrum of species expressing different habitat requirements and dispersal abilities.
Location The study was conducted across the states of Montana and northern Idaho, USA, comprising an area of 30.2 million hectares.
Methods We used resistant kernel modelling to map the extent of the study area predicted to be connected by dispersal for each of 35 species groups with different ecological associations. We evaluated the effect of vagility on protected area sufficiency by varying dispersal ability across three levels for each species group. We evaluated the degree of vulnerability of each of the 105 hypothetical species (35 species groups × 3 dispersal abilities) in terms of the extent of the total study area predicted to be connected by dispersal. We defined nine categories of risk as the combination of species vulnerability because of the extent of connected habitat and the degree to which that habitat was protected.
Results We found high variation in the vulnerability of species because of the extent of connected habitat, and the extent to which connected habitat overlapped protected lands. Species associated with high elevations and species associated with lower elevations were predicted to have limited extent of connected habitat. Species associated with high elevations were predicted to have the vast majority of their connected habitat protected by federal Forest Service and National Park Service lands. In contrast, species associated with lower elevations were poorly protected by the existing network of protected lands.
Main conclusions Low elevation and non-forest habitats are at highest risk of human-induced habitat loss and fragmentation in the study area. Conservation efforts in the region may be most effective if they focus on expanding the network of lower elevation protected lands in such a way that maximizes connectivity across the landscape.