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.