Skip to Content

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

Learning together to mitigate impacts of invasive annual grasses

by Wyoming Livestock Roundup

We’ve heard it before – how does a person build an airplane while they are flying it? What should they do when their destination seems to change mid-flight and the weather conditions and landscape alter without their awareness? 

The best rangeland management seems to combine art and science with a high level of technical skill, creativity, communication and good, old hard work. Knowledge of the land and knowledge of how to best understand its patterns should complement one another.

However, it seems challenging to unite research and management, or science and practice, or knowing and doing. Building stronger connections between these important practices is one primary goal of the University of Wyoming’s Institute for Managing Annual Grasses Invading Natural Ecosystems (IMAGINE). 

Working directly with land managers, researchers and educators are flipping the script on how research is often done by evaluating impacts of operational-scale invasive grass management projects with vegetation monitoring, satellite imagery and creative analysis methods. It seems to be a pretty good fit – land managers get access to information on how effective their treatments are while the whole team learns about how to better manage invasive grasses.

Many projects are ongoing, but I promise to give important insights into management practices, how to best use them in given situations and the broader impacts of management programs in this column. Below are some examples of projects currently under way.

Invasive grass

This cooperative project uses data-science approaches to assess regional relationships among invasive grass abundance and native species composition and diversity. Additionally, the project is evaluating treatment-response patterns across a wide geography to identify consistencies and gaps among invasive grass treatment recommendations.

Evaluating grazing

This graduate student-led project tracks multi-year vegetation trends on multiple sites treated for ventenata control where grazing is either excluded or allowed to occur. Existing recommendations often suggest to defer grazing in an effort to improve perennial grass establishment and recovery, but little empirical data exists to support or refute this practice.

This project will provide initial data to answer the question of whether grazing deferment benefits rangeland recovery following chemical control of ventenata.

grass management 

Indaziflam, a root-growth inhibiting herbicide, is quickly becoming a preferred tool for annual grass management on rangelands. Its ability to inhibit root growth in the upper soil profile makes it an effective tool for managing annual grasses, but it also has the ability to reduce establishment of desirable species in areas where reseeding is necessary. 

This project seeks to better understand how to integrate this effective management tool with appropriate plant materials, seeding depths and seeding times.

Assessing mule deer habitat 

As a subset of a larger study, we are collecting global positioning systems (GPS)-locations for multiple mule deer fitted with GPS collars in Sheridan County and investigating whether their habitat use patterns change following control of the invasive annual grasses ventenata and medusahead.

Invasive annual grass
technology transfer

This cooperative program seeks to put science into practice, helping land managers address the greatest threat to the sagebrush biome – invasive annual grasses. Centered around the proactive “Defend and Grow the Core” framework, a cooperative team from multiple universities, federal, state and local agencies, nonprofits and the private sector will embark on a campaign to equip land managers with the knowledge, skills and tools needed to implement effective invasive annual grass management.

Experts will translate the latest science into highly usable technical materials, foster experiential learning through field workshops and online modules, and establish an innovative multi-state demonstration and monitoring network enabling adaptive management and ongoing technical support.

Regardless of whether a person is a livestock producer whose animals depend on rangeland forage for part of the year, a conservationist who is concerned about the goods and services provided by diverse rangeland plant communities or an individual who cares about wildlife habitat and the opportunities it provides for our society, invasive annual grasses potentially impact their lives. 

For more information on invasive annual grass management in rangelands or to stay up to date on results from the research described here, visit

Brian A. Mealor is the director of the Sheridan Research and Extension Center and the Institute for Managing Annual Grasses Invading Natural Ecosystems. Mealor can be reached at

Back to top