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Success Story

Saving the Sagebrush Sea: A Warner Mountains Success Story

Publish Date
A sage grouse looks out over a sagebrush steppe

Location: Lake County

In the Warner Mountains near Adel, Oregon, a sea of sagebrush extends as far as the eye can see. The mountains run north to south from southern Oregon into northern California.

Sagebrush rolls across hillsides and valley bottoms, providing productive land for livestock and wildlife which supports ranchers, recreationalist and rural communities.

The landscape also supports wildlife. In fact, more than 350 species depend on the sagebrush ecosystem, including pronghorn, mule deer, and the iconic sage grouse.

But after a century of fire suppression, trees like the western juniper have spread from the rocky ridges of the Warner Mountains down into the sagebrush sea. 

In just the past 20 years, more than one million acres of sagebrush have been lost to tree encroachment in the Great Basin. This invasion of trees has been happening for decades all over the world. 

The Problem

The science shows that this expansion of trees impacts the health and resilience of rangelands, putting wildlife at risk. Like many places in the western Unites States, these valuable rangelands are at risk from encroaching trees that displace wildlife, reduce livestock forage, and decrease available water. 

More than one million acres of sagebrush grazing lands in the Great Basin have turned into pinyon-juniper forests in the past two decades alone. 

“By juniper expanding its range, it has impacted a lot of those wildlife species that thrive on open sagebrush areas, so it essentially is habitat destruction for them,” said Todd Forbes, Bureau of Land Management (BLM) Lakeview District Manager.

This spread of junipers also impacts the people who live on the land. As stands of trees become thicker, they siphon precious water from streams, they fuel hotter and more severe wildfires, and they replace native plants that livestock feed on. 

“The juniper was closing in and I was just kind of watching my ranch slowly disappear before my eyes as the juniper got worse and worse," said John O’Keeffe, private landowner and rancher in Adel, Oregon.

Guarding Against the Green Glacier

Unfortunately, trees are taking over America’s grazing lands at an alarming rate. Conifers like Western Juniper have expanded by as much as 600 percent over the last 150 years — and 90 percent of that expansion has occurred in sagebrush country.

Through the USDA’s Natural Resources Conservation Service’s  Working Lands for Wildlife  program, landowners in sagebrush rangelands receive incentives to remove junipers on their property, helping sage grouse populations thrive.  Ranchers who participated in the project are seeing the positive results from restoring sagebrush rangelands on their land.

Beginning in 2010, private landowners teamed up with NRCS, the Bureau of Land Management (BLM), Oregon Department of Fish and Wildlife, and other state and local partners to reclaim disappearing sagebrush range.

Over the next decade, partners worked together to restore sagebrush country across public and private boundaries in the Warner Mountains. Leaving the old-growth woodlands alone, partners focused their restoration on recently-invaded areas that still contained sagebrush and other native plants.

Using chainsaws, they removed young trees from historic rangeland, allowing native plants to rebound quickly. 

"Here in the Warner Mountains project, we’re talking horizon-to-horizon restoration, which is what we need to actually get to in terms of conservation of the sagebrush sea," said Jeremy Maestas, NRCS West Technical Support Center Ecologist.

When the Warner project began, no one knew exactly how tree removal would change things. To find answers, scientists from the BLM, NRCS, University of Idaho, and Oregon State University monitored plant and animal species in the area. They also tracked over 400 sage grouse hens over eight years. 

“They’re really an early indicator of how things are going," said Maestas. "So goes a sage grouse, so goes the sagebrush sea, and we really wanted to use that as a barometer of how well our restoration actions were working.”

A Private-Public Lands Partnership

"The big value is that removing conifers gives you a reset," said John O’Keeffe, who ranches near Adel, Oregon, and partnered with NRCS Oregon to remove junipers on his property. “As the trees get thicker and thicker, you lose your understory vegetation and that puts your topsoil at risk. Conifer removal keeps the land in a state where we have native bunchgrass that allow for cattle, grouse, deer, and antelope. Once the conifers get too dense, you lose all of that.”

Using hand-held chainsaws to minimize ecological disturbance, private landowners like O’Keeffe worked alongside public land managers at BLM to strategically remove trees from 34,000 acres (53 square miles) to restore and expand sagebrush habitat.  

The project partners targeted tree removal places where there was still a healthy understory of native shrubs and plants so birds could move into the habitat right away.

Success in the Sagebrush Sea

With support from the NRCS Conservation Effects Assessment Project, the partners teamed up with university scientists to closely monitor the outcomes of tree removal. They paid special attention to how sage grouse populations fared.  

Prior to this project, little was known about the true impact of woodland expansion on wildlife habitat. Partners tracked the research projects over a period of eight years, from the start to finish from 2010-2017, discovering several important outcomes for sage grouse along the way. 

“Once we began cutting trees on the landscape, bird behavior would change where we would see nesting in areas where we hadn’t seen nesting before," said Forbes.

“What really surprised us is how fast the sage grouse reoccupied those former habitats; they started nesting there almost immediately,” said Maestas.

Within three years, scientists documented a third of marked sage grouse nested in restored sagebrush habitat. In addition, nest success increased by 19% once trees were cut.

As a result, the sage grouse population in the restored areas grew at a rate that was 12% higher than those in neighboring areas with trees.

“This is extremely encouraging for the future of sage grouse conservation,” said Maestas.

The amount of high-quality sage grouse habitat increased six-fold after juniper removal. Other wildlife benefited, too. For example, researchers found that the abundance of sagebrush songbirds doubled soon after tree removal. 

And now ranchers are breathing easier, too, with more space and better forage for their grazing cattle.  

"I really felt like I was getting my ranch back once we really got into doing it at a landscape scale,” said O’Keeffe.

Nationwide Model of Conservation Success 

Successful restoration projects at this scale are only possible through partnerships.   

Indeed, the resounding success in the Warner Mountains is being replicated in other watersheds across the sagebrush sea as partners come together to tackle the problem of tree invasion and achieve similar outcomes. 

Since 2010, NRCS Working Lands for Wildlife has partnered with over 2,000 landowners in communities across the West to remove encroaching trees from 700,000 acres of rangelands. By working together, we can create healthy, resilient working lands that support people and wildlife for generations to come. 

“The main advice I would have is don’t be afraid to jump in with both feet. Talk to all of your partners - there’s other people out there in your community, other agencies that will help you. Bring everybody to the table, talk about what you want to do, talk about your overall broad concept and it will come together," said Forbes. "But don’t be afraid to move forward and try something, because it is possible.”

Thank you, partners!

  • Bureau of Land Management
  • Ranchers
  • Working Lands for Wildlife
  • Oregon State University
  • University of Idaho
  • Oregon Department of Fish and Wildlife
  • NRCS Conservation Effects Assessment Project
  • Lakeview Soil and Water Conservation District