99th ESA Annual Meeting (August 10 -- 15, 2014)

OOS 2

20 years of Restoration following Cessation of Livestock Grazing: Lessons from Hart Mountain National Antelope Refuge

The sagebrush biome is among the most endangered ecosystems in western North America. This is due to the interacting impacts of overgrazing by domestic livestock, introduction of invasive species, altered fire regimes, human development (eg., roads) and climate change. Land managers are actively seeking strategies to preserve and restore the natural structure and function of this ecosystem. Domestic livestock grazing affects the greatest land area of any land use in the western USA. In the late 1800’s and early 1900’s, it is estimated that over 45 million cattle and sheep were grazed on Western rangelands. Although today these numbers have declined by more than half, permitted livestock use still occurs on nearly one million square kilometers of public land. Domestic livestock have had deleterious impacts on sagebrush biodiversity including soil compaction/trampling, excesive utilization of native plants, alteration of fire regime, and dissemination of exotics. The long-term effects of domestic livestock and patterns of recovery following their removal are poorly understood in sagebrush ecosystems, and to date have been largely limited to small exclosure studies. However, livestock removal on the 110,000 ha Hart Mountain National Antelope Refuge (HMNAR), Oregon, in 1990 has provided an opportunity to examine landscape scale changes associated with this passive restoration approach. The HMNAR provides critical habitat for an abundance of wildlife species, including sage grouse, pygmy rabbit, bighorn sheep, and pronghorn antelope. Current studies are underway to examine responses of wildlife and their riparian and uplands habitats. The HMNAR can provide a model for passive restoration efforts elsewhere in the Great Basin and semiarid west. This symposium will provide the history and results of current research on flora and fauna in riparian and upland plant communities within HMNAR.