Michael Wisdom, Pacific Northwest Research Station
The sagebrush (Artemisia spp.) ecosystem once occupied over 60 million hectares of western North America. The ecosystem has been reduced in area by 40-50 percent since European settlement, and less than 10 percent remains in a condition unaltered by human disturbances. The ills of the sagebrush ecosystem are well documented. Millions of hectares have been converted to agriculture, cities, roads, transmission lines, energy developments, exotic plants, and woodlands. Moreover, the loss appears to be accelerating, and management intervention thus far has been ineffective in abating the rate of loss, let alone reversing it. Despite the challenging outlook, a framework for planning strategically across the ecosystem, using spatially explicit, prioritized management to address maintenance needs of existing sagebrush communities, could substantially improve the odds of successfully minimizing further loss and degradation. I illustrate this process with projections based on published maps of risk posed by various threats to sagebrush, and to a signature species of the ecosystem, the Greater Sage-Grouse (Centrocercus urophasianus). The projections suggest that the concept of threshold effects, combined with substantial and sustained management aimed at controlling all undesirable forms of human disturbances, are key to maintenance of the ecosystem and species like sage grouse. Ecosystem-wide spatial priorities and associated, strategic policies and direction, combined with a substantial increase in funding for follow-on management, are essential ingredients for mitigating current, undesirable trajectories for the sagebrush ecosystem and its species.