The West’s sagebrush wild lands have long been viewed as a throwaway landscape, managed for commodity production under fallacies promoted by the livestock industry and many range professionals. Anti-sagebrush, myth-based management has been pervasive. Virtually all sagebrush wild lands are grazed, resulting in altered species composition and structure, and disruption of ecosystem functioning. There is now widespread recognition of the spiraling loss, fragmentation, and endangerment of sagebrush habitats.
Characterized by bunchgrasses, forbs and shrubs with soil interspaces of microbiotic crusts, the sagebrush ecosystem did not evolve with herds of large, hoofed ungulates. The current vegetation originated in the Pleistocene, with little grazing by large native herbivores, and bison scarce in the intermountain region.
“The vegetation of the pristine sagebrush/grasslands was relatively simple and extraordinarily susceptible to disturbance … the native vegetation lacked the resilience, depth, and plasticity to cope with concentrations of large herbivores. The plant communities did not bend to adapt; they shattered. This tends to make the review of grazing in the sagebrush/grasslands a horror story, resplendent with examples of what should not have been done.”
Habitat fragmentation proceeds at multiple levels, so that even where a veneer of sagebrush remains, livestock may have removed or simplified critical habitat components for native animals. For example, sagebrush broken and battered by livestock loses the structural complexity of overhead cover required by pygmy rabbits. Livestock degradation sets the stage for irreversible change. Native bunchgrasses are weakened and killed by the chronic effects of livestock grazing. Microbiotic crusts that fix nitrogen, protect against erosion, and help exclude weeds are destroyed by trampling. Alien annual cheatgrass and other weeds invade depleted understories. Livestock facilitate weed dispersal, transporting seeds in fur, mud, and dung.
Cheatgrass produces continuous fine fuels, so that fires flash across the landscape. Larger and larger areas burn more frequently and uniformly, leaving fewer unburned patches. As this phenomenon accelerates, the landscape is converted to annual grassland. Remaining sagebrush habitat patches become smaller; species disappear. This destructive transformation is visible today across southern Idaho and is now creeping into the Owyhee Canyonlands.
The OI plan would accelerate this multi-layered fragmentation, both by sanctioning – even increasing – existing grazing, and by facilitating more livestock-related developments and management schemes. Fences concentrate livestock, allowing more uniform degradation and new zones of heavy disturbance. Livestock water developments dig into the heart of wild springs, disrupt stratigraphy, remove water, and may cause springs to dry up. Pipelines ripped outward across the sagebrush extend chronic grazing degradation and weeds into the few remnant islands of pristine sagebrush that may remain. Roads to salt sites, pipeline routes, and fence lines become conduits for weed spread, and create new travel corridors for nest predators.