Skip to Content

The Weekly News Source for Wyoming's Ranchers, Farmers and AgriBusiness Community

Toolkit released for annual invasive grass management

by Wyoming Livestock Roundup

The Western Governors’ Association (WGA) recently hosted a webinar to launch a toolkit providing for annual invasive grass management in the West. The toolkit was created in response to a 2019 shared stewardship Memorandum of Understanding (MOU) between WGA and the United States Department of Agriculture (USDA). 

“Federal, state and private managers of forests and rangelands face a range of urgent challenges, among them catastrophic wildfires, invasive species, degraded watershed and epidemics of insects and disease,” the MOU states. 

“The toolkit will help state, federal and local managers address the large-scale infestation of cheatgrass and other invasive annual grasses on western forests and rangelands,” says WGA Executive Director Jim Ogsbury. 

WGA and USDA were assisted by the Western Invasive Species Council (WISC) to target cheatgrass, medusahead and ventenata. WGA, USDA and WISC enrolled help from the U.S. Forest Service, the USDA Natural Resources Conservation Service (NRCS), the U.S. Fish and Wildlife Service (USFWS), the U.S. Geological Survey (USGS), representatives from Western state agencies, land grant universities and stakeholder groups to develop the toolkit. 

“The project is an example of the cross-boundary, cross-jurisdictional cooperation needed to tackle some of the West’s largest problems,” Ogsbury states. 

The toolkit is based on a new conceptual model, “Defend the Core, Grow the Core, Mitigate Impacts,” and is comprised of three main elements including a roadmap for invasive grass management practices, case studies highlighting the practices and a data layer for land managers to utilize. The elements were designed to be easily customizable to local areas for implementation. 

Management model 

The toolkit suggests defending large cores from invasion and annual grass conversion as the first step and a top priority for management. Cores are defined as areas of little to no annual grass invasion that serve as important anchor points for conservation and restoration. 

While defending cores from invasion, the toolkit recommends growing the core areas by pushing back any invasion with early detection and vigorous management to prevent the spread of invasive species. 

“Prevention, early and aggressive management of annual grass invasions and promotion of a healthy perennial system is needed to maintain and build resistance and resilience of cores,” states the toolkit. 

Addressing transitional zones where annual invasive grasses already exist or where the land is susceptible to new invasions is critical in maintaining cores in a cost-effective manner, according to the toolkit. 

“As an invasion starts, management is low cost and can be very effective at eradication and control if we attack the invasion early by being proactive,” says USFWS Sagebrush Ecosystem Invasive Species Coordinator Lindy Garner. “But, as the invasion increases over time, the management costs increase, and we return to a reactive mode of trying to respond with long- term management that is very costly and less likely to be successful.” 

Mitigating impacts is the last element of the model, focused on degraded areas severely impacted by invasive grasses. Actions for mitigation include fuels reduction and fire suppression as asset protection, according to the toolkit. 

“While this toolkit emphasizes the importance of proactive management of intact areas and identifies the preferred direction of action, it acknowledges that continued management of other lands will be needed, so the third element is to continue to mitigate the most severe impacts of the cheatgrass cycle,” continues Garner.

Data-driven roadmap 

With help from the Rangeland Analysis Plat- form at the University of Montana and the National Land Cover Database from the USGS, a combined data layer was created to show the percent cover of herbaceous annual plants on rangelands to help managers better understand the condition of the land. 

“On our rangelands, annuals don’t make up a large proportion of plant cover most years,” says USDA-NARCS Ecologist at West National Tech Support Center Jeremy Maestas. “If we see persistent annuals from year to year on the landscape we think that is a pretty good surrogate for the extent of invasive annuals on our grassland.” 

The interactive map predicts what percentage of the land is made up of annual grasses. The map can be viewed at large-scale areas like regions and states or at the pasture level. 

The map has been an integral tool for land managers to keep tabs on cores and transitional zones and monitor any changes in the plant communities. 

“We can identify areas with environmental conditions making them susceptible to invasion by annual grasses,” says University of Wyoming Sheridan Research Center Director and Associate Professor Brian Mealor. “The map is valuable in identifying important places to monitor for this invasion and implement prevention management practices.” 

“We can’t possibly prioritize the landscape like local land managers, so we are providing products with a tremendous amount of flexibility,” says Maestas on the availability of the map and toolkit for land managers. 

“Combine the map in this toolkit with expert knowledge in the local area to refine a approach for managing annual grasses,” Mealor recommends. 


“The ranchers I talk to have told me cheatgrass has become a deciding factor to whether or not they are profitable, losing useful feed to a less than useful source is a real tragedy,” notes National Audubon Society Sagebrush Ecosystem Initiative Director Brian Rut- ledge. “We have to find a way to pull together across all boundaries to make this work together.” 

“In summary, the challenge of invasive annual grasses is widespread, but we have an opportunity to increase our collaboration and move the needle with more proactive management,” says Garner. 

“We hope the tool- kit provides some inspiration. It’s a set of ideas, data and examples of how these ideas have been implemented. Hopefully, it will start to be contagious around the West, and we end up with a somewhat unified approach of how to tackle this really persistent and serious threat,” says Maestas. 

“The toolkit is a great baseline,” says Northeast Wyoming Invasive Grasses Coordinator for the University of Wyoming Extension Jaycie Arndt. “More land managers can be on the same page when it comes to annual invasive grass management.” 

“We must continue to learn and refine our management processes as we move forward,” adds Mealor. 

Averi Hales is the editor for the Wyoming Livestock Roundup. Send comments on this article to

Back to top