Trends in road development and access management in the Cabinet–Yaak and Selkirk grizzly bear Recovery Zones

Abstract

Unlimited use of forest roads can result in taking of grizzly bears (Ursus arctos) and reduced progress toward recovery. We examined trends in road development and motorized access management in the Cabinet–Yaak and Selkirk grizzly bear recovery zones by evaluating 3 bear management units (BMUs) for amount and density of open and total roads and security core habitat during 3 periods (1975, 1987, and 2001). New road construction and access management activities such as road use restrictions, road closures and road decommissioning governed the amount and kinds of roads present. In 1975, nearly all roads were open to public access, but the amount of open roads declined during subsequent periods. Closed roads increased correspondingly, and by 1987, public motorized access was excluded from the majority of roads in some BMUs. Road decommissioning, nonexistent in 1975 and 1987, was common by 2001. Even with new construction, there were fewer open roads in 2001 than in 1987 and 1975 for all 3 BMUs examined. Due to road decommissioning, the total length of roads in 2001 was less than during at least 1 of the 2 previous periods for all BMUs examined. For most BMUs, open motorized route density (OMRD) and total motorized route density (TMRD) peaked in 1987, and security core habitat reached its lowest level during that period. However, access management activities after approval of Forest Plans in 1987 resulted in decreases in OMRD and TMRD and increases in security core habitat. As of 2002, most of the 30 BMUs in the Cabinet–Yaak and Selkirk grizzly bear recovery zones either met or were moving toward recommended OMRD, TMRD, and security core levels. Improved habitat security through reduced open and total road densities and increased security core habitat is likely to assist in limiting grizzly bear mortality and enhancing the likelihood grizzly bears will persist in these recovery zones. Had these improvements in security not occurred, we believe these grizzly bear populations would be even more imperiled than they currently are.