Prioritizing effective and sustainable management approaches for cheatgrass and ventenata in Montana rangelands

Commodities

• Agronomic: grass (misc. perennial)

Practices

• Pest Management: weed ecology

Cheatgrass (Bromus tectorum) is a notorious invasive, non-native annual grass, invading large areas of the sagebrush steppe and western rangelands. Ventenata (Ventenata dubia) is a more recent non-native annual grass invader to these ecosystems, is less palatable than cheatgrass and capable of replacing cheatgrass in some areas. Where these invasive annual grasses dominate, they reduce forage production for cattle and habitat quality for wildlife. Restoring highly infested rangeland is both difficult and resource intensive. Targeting areas with low to moderate and patchy levels of infestation could prevent further expansion before the system reaches the no-return tipping point. Similarly, a new strategy “Defend the Core” suggests targeting areas of low-moderate invasive grass invasion because these areas can see the greatest recovery and economic benefit. Much of the northeast region of the sagebrush steppe and other grasslands (e.g., Montana, Wyoming, central-north Idaho) falls into this low to moderate abundance category, and producers in this region are concerned about invasive annual grasses expanding and want help now, before the problem worsens.

Our goal is to develop a prioritization and decision framework tool to help producers select the most appropriate management strategies to control cheatgrass and ventenata and ensure recovery of desired vegetation, to improve the sustainability of their ranches and livelihoods. Because management effectiveness differs according to the degree of invasion, site conditions (e.g., slope, native plant cover) and control strategy used (herbicide, soil amendment, restoration seeding) these factors, along with cost-benefit analysis, will be the basis of the decision tool. The data for this tool will come from current and future studies. We will continue evaluating the effect of integrated weed management strategies to control cheatgrass (WSARE SW20-915) and ventenata (WSARE GW22-237) at our study sites. Our collaborators have suggested we take the best management strategies and apply them on a larger scale than our current plots to further evaluate their effectiveness, at six sites in southwest and west Montana. Because of the interest from our producer collaborators and other ranchers in soil amendments, we have added them to our experimental treatments. At our larger scale study, we will assess not only invasive and desired plant response but also forage quality and soil health. 

With this multi-partner, producer-driven project, we will develop a prioritization and decision framework tool that incorporates an economic analysis of trade-offs created by management strategies with landscape and climate attributes for producers, land managers and other interested stakeholders. The whole project team will participate in the research and education objectives, including dissemination of our research results and decision tool using an array of approaches (field days, seminars and presentations at local and regional meetings, web posts, fact sheets, university classes, and scientific manuscripts). Short and longer term adoption will be monitored by our extension specialists. Project outcomes will guide selection of the most effective ecologically and economically sustainable management approaches for invasive annual grasses for our rangelands in southwest and west Montana, the larger northeast region of the sagebrush steppe and northern Great Plains of the American West.

Research Objectives

1) Quantify the effectiveness of different management strategies to control invasive annual grasses (cheatgrass and ventenata) and increase desired vegetation.

2) Large plot evaluation of the most effective management strategies to reduce invasive annual grasses and increase desired vegetation.

3) Develop a prioritization and decision framework tool to manage annual invasive grasses and desired vegetation for ecological and economical sustainability.

 Education Objectives 

1) Develop regular communication with our collaborating producers to ensure information sharing.

2) Create outreach products, on conditions where cheatgrass and ventenata are most likely to reach high abundance, the efficacy of different management practices to control them, and the prioritization and decision framework tool.

3) Demonstration of treatments effects.

4) Dissemination to future producers, managers and the general public.

5) Publication of research outcomes.