sagebrush

Sagebrush seeded after prescribed fire. Photo by Dr. Kirk Davies.

A team of 94 scientists and specialists from 34 federal and state agencies, universities, and non-governmental organizations assessed the sagebrush ecosystem, covering 14 Western states and two Canadian provinces.

Considered an at-risk ecosystem with more than 350 species of conservation concern, the sagebrush ecosystem has lost 55 percent of its extent and continues to shrink rapidly due to several growing threats, according to the report. The 364-page report titled, Sagebrush Conservation Strategy—Challenges to Sagebrush Conservation, highlights the loss of sagebrush habitat due to “altered fire regimes, invasive plant species, conifer expansion, overabundant free-roaming equids, and human land uses.”

“In order to effectively counter challenges, we first have to understand them,” said Director of the Nevada Department of Wildlife and Chairman of the Sagebrush Executive Oversight Committee Tony Wasley in a statement. “This report gives us a clearer understanding of these threats as well as how to restore degraded sagebrush rangelands and communicate the need for conservation to the public. It’s clear while we individually are winning many battles, we are at risk of collectively losing the war to conserve sagebrush, particularly with regard to fire and cheatgrass.”

Warming temperatures due to climate change and drought have contributed to the increase in the frequency and size of wildfires in the sagebrush biome. The expansion of annual grasses has resulted in large-scale wildfires that have consumed large expanses of sagebrush in recent years, threatening efforts to conserve sagebrush-associated wildlife.

The report noted that since 2000, 20.6 percent of greater sage-grouse priority habitat management areas within the Great Basin has burned. While invasive annual grasses have not affected the sagebrush biome’s eastern portion, wildfire frequency is expected to increase due to established bromegrass species.

Additionally, the expansion of pinyon pine and juniper contributed to the degradation of the sagebrush ecosystem with competition for water, less forage for livestock grazing and decline of species dependent on the sagebrush biome. The report noted that in the last four to six years, 87 percent of conifer removal occurred through state and federal initiatives but represented only 1.6 of the area across the sagebrush ecosystem.

Further contributing to the loss of sagebrush habitat is the overabundance of wild horses and burros. According to the Bureau of Land Management in March 2019, the appropriate management levels for the animals was 26,690, but an estimated 88,090 wild horses and burros were inhabiting designated herd management areas. Without management efforts to reduce the population to appropriate levels, the population is expected to double in four years, further competing for water and forage with species dependent on the biome and livestock for grazing.

The report noted human-caused activities such as energy development, cropland conversion, infrastructure, and improper livestock grazing also contributed to the degradation of the sagebrush biome.

“All human uses of sagebrush landscapes impact ecological processes and wildlife, but effects can be positive or negative and vary tremendously in degree depending on the land use, site conditions, and species,” the report stated. “For example, well-managed grazing can foster productive rangeland for cattle and wildlife; however, poorly managed grazing can lead to a reduction in grass cover and soil erosion and compaction.”

While federal and state regulations were developed to mitigate energy development and mining, approximately 8 percent of sagebrush habitats are affected by oil and gas development. The report stated 20 percent of development occurred in the Rocky Mountain region and has affected species dependent on sagebrush. However, mitigation efforts of controlling energy development are largely unknown.

Cropland conversions have occurred chiefly in eastern Washington, eastern Montana and Wyoming, which accounted for 10 percent of the loss of the sagebrush ecosystems. The report stated if a significant loss of sagebrush habitat occurs, those species dependent on the biome may abandon the area. Tall structures such as powerlines and cell phone towers can fragment habitat leading to avoidance by some species, such as ground-nesting birds. Still, they could also provide additional perching habitats for species of concern, such as golden eagles.

The report also highlighted efforts underway through state, federal and nonprofit organizations to reduce the harmful effects of human land use. The collaboration provides “voluntary protection mechanisms” and cost-share programs for private landowners to conserve and maintain sagebrush lands. Government agencies are closing roads during the breeding season, managing recreational activities, and constructing wildlife road crossings to minimize conflicts. Mitigation efforts are active in states to help avoid and offset impacts from ongoing land use development, such as new pipelines or transmission lines.

While sagebrush restoration primarily focused on the greater sage-grouse population, the species is “considered a conservation umbrella, meaning efforts for this wide-ranging species may also conserve habitats of other sagebrush-obligate, -dependent, or -associated species.” The report stated conservation for the sage-grouse umbrella indicated it may serve as a model of an effective collaborative conservation approach for conserving sagebrush species rather than replacing broader conservation efforts.

“The bottom line is, sage-grouse conservation efforts are a great start, but we can’t just assume that these alone are going to take care of mule deer migration routes, wintering areas, pygmy rabbits, pronghorn or human needs from these landscapes,” said Tom Remington, the report’s lead editor and Western Association of Fish and Wildlife Agencies coordinator. “There are many examples where state, federal, or private efforts are successfully addressing these challenges collaboratively. We can conserve the sagebrush biome if we coordinate our actions to emulate these and scale them up.”

The executive summary in the report noted the collaboration “will be a daunting task given the amount of habitat in need of restoration.” However, improvements in planning and prioritization with restoration efforts are likely to improve restoration success. “Opportunities remain to better incorporate current knowledge into restoration practice. The greatest challenge in the restoration of sagebrush landscapes will likely be obtaining resources to scale up efforts to the degree necessary to meet restoration objectives.”

The summary noted with 50 percent of the sagebrush biome on federal and state lands, communication, outreach and public support are essential to ensure a sustainable future of the sagebrush ecosystem. — Charles Wallace, WLJ editor

 

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