Opinion – Restoring the sagebrush sea by addressing the pinyon-juniper invasion

What is the one western public lands issue on which just about everyone — ranchers, firefighters, endangered species advocates, hunters, locals and historians—agrees? The answer may surprise. It is the restoration of native plant communities to the western landscape. In particular, renewal of the high plains’ vast sagebrush sea.

That’s because restoring native sagebrush in Northern California, Oregon and across the West will benefit both people and wildlife by providing habitat for hundreds of native species, while reducing fuel loads and fire danger to hundreds of communities.

The vast sagebrush-steppe ecosystem of the West inhabited by American Indians and greeted by settlers 150 years ago has in the intervening years since been reduced to less than half its historic size. One of the biggest causes of this decline is the invasion of pinyon-juniper species — they are distinct and do not always appear together — into shrub-steppe communities. At the time of settlement, pinyon and juniper woodlands occupied an estimated seven million acres of land. Today they occupy over 74 million acres. That 10-fold increase over the last 150 years has many causes, including fire suppression, over grazing, land clearing, and changing weather and rainfall patterns.

Habitat loss from pinyon-juniper invasion has been devastating for the greater sage-grouse – once estimated to number as many as 16 million birds prior to settlement, and now closer to 200,000. The greater sage-grouse is an umbrella species, emblematic of the health of sagebrush habitat it shares with more than 350 other kinds of wildlife, including populations of mule deer, elk, pronghorn, and golden eagles. Invasion by pinyon-juniper woodlands degrades, destroys, and fragments wildlife habitat by displacing sagebrush, other shrubs, and herbaceous understory. At the same time, these woodlands provide abundant perches for avian predators of sage-grouse.

Like sage-grouse, mule deer have suffered a dramatic decline due to pinyon-juniper induced habitat modification. In Colorado, recent populations are half of what they were 65 years earlier; likewise, in California. In New Mexico and Utah, the mule deer population was halved in less than 30 years. Worst of all, in my home state of Wyoming, it was cut by a third in just 11 years.

Loss of sagebrush habitat is not just bad for wildlife and native plants. It is terrible for the people and communities that share the landscape. Invading woodlands have higher fuel loads and densities, making catastrophic wildfires more intense and more frequent. Burned areas are then colonized by invasive grasses such as cheatgrass and leafy spurge. Some researchers believe this feeds a self-reinforcing feedback loop of weed dominance and recurrent fire at increased intervals called the grass/fire cycle.

The sage-grouse decline has spurred an unprecedented and thus far successful 11-state effort by the BLM and dozens of federal, state, and private partners to protect and restore sagebrush habitat to keep the species off the Endangered Species list. As part of that effort, the BLM has outlined an ambitious project with our state and federal partners to reduce pinyon-juniper woodland density and restore native plant communities.

This involves using mechanical means to cut, mulch, and remove pinyon and juniper trees on thousands of acres. It may look like devastation to the casual observer, but at the biological level it is the start of a relatively short recovery process. Years of studies show that, like the natural fire regime that once renewed forests before human intervention, proper removal and reseeding with native seeds leads to significant regrowth of sagebrush and other native vegetation within three years, leading to subsequent return of nesting sage-grouse and other species. A visitor returning four years later will see a landscape much more like the one lost decades earlier.

To accelerate this process and spur restoration efforts on a broader scale, we proposed a categorical exclusion (CX) under the National Environmental Policy Act. CXs are used when the agency is confident that the subject of the proposed action does not have significant long-term environmental impacts. The Council on Environmental Quality regulations implementing the Act have long recognized that it is neither efficient nor useful to do repeated analyses for actions that have been proven over time to have no significant environmental impacts, and this common sense solution fits the bill.

We have prepared scores of environmental assessments for pinyon-juniper projects over the years and not one revealed a significant environmental impact. Independent, peer-reviewed scientific studies have confirmed these findings. Given this data, the BLM has proposed the establishment of a CX for pinyon-juniper projects of up to 10,000 acres. In this way, it will accelerate sagebrush restoration efforts and also enable us to focus our limited resources on preparing more detailed NEPA analyses for projects with much greater impacts; a win-win.

We are in the process of analyzing comments and information received from the public and other stakeholders last spring to inform our final decision. This authority will give our land managers and a broad coalition of federal, state, and local partners another tool to restore the Sagebrush Sea for the benefit of both wildlife and people.


About William Perry Pendley

                  William Perry Pendley is the deputy director for programs and policy for the Bureau of Land Management.