U.S. Fish and Wildlife Service

A closeup of sagebrush and cheatgrass on a bright, sunny day.

Invasive weeds and wildland fire

Information icon Sagebrush plants surrounded by cheatgrass. Photo by Jennifer Strickland, USFWS.

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Infestations in sagebrush country of invasive, non-native plants like cheatgrass, medusahead, and ventenata threaten local economies, wildlife, agricultural productivity, recreational opportunities, and human safety. They are ecosystem disruptors. Fast to spread and hard to control, instances of invasion have reached historic rates.

An estimated 100 million acres of public and private lands are infested. Left unchecked, these lands will:


The Problem Plants

A three-picture layout of invasive grasses. From left to right - a close-up of ventenata grass, a close-up of cheatgrass, and a close-up two pods of medusahead grass in a person's hand
From left to right: ventenata, cheatgrass and medusahead. Photos by Jennifer Strickland, USFWS.

The Weed and Wildland Fire Cycle


Not all fire is bad. In fact, it is a natural part of the sagebrush ecosystem, and when sagebrush burns and comes back, it continues a cycle thousands of years in the making.

The problem is that this naturally occurring event is being exacerbated by the invasion of plants like cheatgrass. Fires become more frequent and intense when these grasses are present than they would than under natural conditions. These plant invasions, and the associated wildland fire cycle, are among the greatest concerns in the sagebrush ecosystem within the Great Basin. Here, the loss of sagebrush and its associated habitats is due primarily to the proliferation of invasive plants and the associated increases in the intensity, scale, and frequency of wildfires in sagebrush ecosystems.

Without intervention, invasive plant-driven catastrophic wildfires are expected to continue to alter sagebrush ecosystems, causing a decline in habitat for native plants and animals.

A wildfire rages across a sagebrush landscape
The Castle Rock wildfire burned sagebrush habitats near Ketchum, Idaho. It was fueled in part by cheatgrass. Photo: Kari Greer, USFWS.

Frequent fires can eliminate or destroy areas of sagebrush and native perennial grasses beyond a point where they can restore themselves. Sagebrush must regenerate from seed and can take several decades to recover. In many areas, especially in areas of low rainfall, invasive annual grasses can outcompete native species after fire and they remain highly susceptible to subsequent fires. The threat posed by this cycle of invasive annuals and increased wildfire is well recognized and there is much activity directed to address the problem. We have been aware of this problem for a while. Even in 1949, scientists recognized the threat of invasive annual grasses, specifically cheatgrass, when Aldo Leopold, in his seminal book, “A Sand County Almanac,” penned a chapter with the title, “Cheat Takes Over.” He described the risks to native ecosystems and issued a call for action. Unfortunately, our actions have not yet been successful in stemming the tide. But we’ve learned a lot in that time.

We're continuing to work with a variety of partners to address this massive threat to sagebrush country. This 5-minute video shows some of the people and places on the frontlines of this fight.


Our Success Stories


Stopping the spread of invasive plants and restoring the native plant communities destroyed by extreme wildfires are two of the most critical land management challenges in sagebrush country today. U.S. Fish and Wildlife Service scientists are collaborating with other state and federal agencies to find solutions. Here are some of our success stories.

Integrating the National Seed Strategy in Nevada

The Service is fighting invasion to achieve restoration by providing funding to increase stocks of native seeds to support the stabilization, rehabilitation and restoration of sagebrush habitats on public and private lands affected by invasives and wildland fire. We have deployed native seed collection crews to join Bureau of Land Management and Forest Service crews in northwestern Nevada. We are also collaborating with Nevada Department of Ag to integrate a national Early Detection/Rapid Response (EDRR) component to capture any new invasions identified while collecting native seeds. The crew is also partnering with Sheldon Hart National Wildlife Refuge on collection activities.

Increasing Capacity in Lake and Harney Counties, Oregon

Utilizing active Cooperative Weed Management Areas, Lake and Harney counties are working closely with federal and state partners to identify place-based conservation actions in priority areas. In 2017, Lake County treated 11,000 acres of annual grasses and weeds, mainly medusahead and ventenata, while Harney County treated 7,000 acres. Success is defined by multiple federal and state partners, including the Bureau of Land Management. Using one of our voluntary conservation tools, Candidate Conservation Agreement with Assurances, the Service is working with those partners to define conservation measures for rangeland restoration for sage-grouse, which include invasive species management. Consistent, long-term funding would benefit this project as it requires multi-year treatments to achieve effective annual grass reduction on the sites.

Increasing Funding in Washington State

To better address invasive plant issues in the heart of Washington’s greater sage-grouse country, the Service worked with Foster Creek Conservation District in Douglas County on a grant to form a Cooperative Weed Management Area in the state. The Conservation District is working on an additional funding agreement to enable the Service, and other partners, to function like a weed board to develop and implement a plan to manage and prevent the spread of invasive species within Douglas County. This will lead to strategic and more effective control of invasive plants across more than one million acres of shrub-steppe habitat, rangeland, and farm land, as well as benefits to the greater sage-grouse, endangered Columbia Basin pygmy rabbit, and two other state-listed species.

Strengthening Coordination in Southwestern Wyoming

Over the past decade, the Wyoming Landscape Conservation Initiative in southwestern Wyoming has built strong partnerships at the local level, furthering collaborative efforts to manage invasive species, improve rangeland health, provide livestock forage, and improve habitat for mule deer, elk, and greater sage-grouse. Leveraging BLM Healthy Lands Initiative dollars, approximately 54,000 acres of cheatgrass on private and federal lands were treated. The Initiative also treated 14,800 acres of tamarisk and Russian olive, 3,300 acres of perennial pepperweed, 5,000 acres of leafy spurge, and 48,000 acres of other noxious weeds in the state. This work continues to include new partners with Wyoming industries, while facilitating local land management.

Improving Responsiveness in Northeastern Wyoming

In northeastern Wyoming, the first invasions of medusahead in the Northern Great Plains have been recorded, as well ventenata and other invasive annual grasses. These invasives threaten greater sage-grouse core habitat and seasonal range for elk, moose, mule and white-tailed deer, and pronghorn antelope. The Service supported local partnerships working to respond to these new threats by implementing early detection and rapid response techniques as outlined by the National Early Detection/Rapid Response (EDRR) Framework, treating the medusahead population within one month. Resources were leveraged among private landowners, state offices, the National Invasive Species Council, several federal agencies, and the University of Wyoming. In 2017, 23,000 acres were surveyed. 400 infested acres of medusahead and other invasive annual grasses were found, resulting in 2,500 acres treated. Extensive outreach to the local community was conducted.

A close-up image of a ventenata seed wedged inside a button on the photographer's shirt
A ventenata seed in the photographer’s clothing. Photo by Jennifer Strickland, USFWS.

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