Duration: 10/01/2023 to 09/30/2028

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Rangelands of the western U.S. are impacted by numerous stressors that affect their ability to provide ecosystem goods and services for society. Fire, energy development, exurban subdivision, the transportation network, extreme climate events, and changes in land use are all examples of disturbances that can impact rangeland vegetation and exacerbate the spread of invasive weed species, including invasive grasses. It is difficult to disentangle invasive grasses from these stressors because their establishment and spread is facilitated by altered disturbance regimes.

Invasive grasses pose a particularly difficult management challenge: how do land managers selectively remove a grassy weed from systems largely comprised of desirable grasses? Detecting, identifying, and mapping relatively cryptic grass species within a ‘sea’ of other grasses is more difficult than doing so for large, showy, flowering plants. Moreover, negative impacts of invasive grasses are less intuitive to some landowners because they may view them as another source of forage, although data indicate their forage production is undependable and highly variable among years.

Cheatgrass (Bromus tectorum) alone is estimated to impact over 100 million acres (~405,000 ha) of western rangelands. Few other invasive plant species have such a broad ecological extent. Ventenata (Ventenata dubia) and medusahead (Taeniatherum caput-medusae) are rapidly expanding their ranges and colonizing some habitats previously impacted by cheatgrass. In the Southwest, species such as Lehmann lovegrass (Erogrostis Lehmanianna) and buffelgrass (Pennisetum cilare) outcompete valuable native forage grasses and increase fire frequency. Species previously considered ‘crop weeds,’ such as jointed goatgrass (Aegilops cylindrica), are now invading rangeland systems. Already a prominent resource concern by the early 1940s, the invasive grass problem continues to become more complex and difficult to manage. Inaction will likely lead to further invasion and greater negative impacts on ecosystem health and functionality, economic vitality, and restoration potential.

Recent developments in ecological understanding, technology, and government policies may make successful long-term, landscape-scale management a reality. West-wide emphasis on spatial prioritization facilitated by remotely-sensed data has dramatically increased recently (Creutzberg et al. 2022, Jones et al. 2020, WGA 2020), but there remains a meaningful knowledge gap for land managers, advisors, and practitioners in situation-specific responses for invasive grass management actions.  Additionally, regional prioritization efforts based primarily on satellite-derived data present testable hypotheses about site-specific plant community conditions and potential for recovery following invasive grass control. A coordinated effort, integrating research, education, and outreach, is needed to enhance communication and action among western states to tie together related research programs focused on ecology and management of invasive grasses in rangelands.

We propose the establishment of a multi-state project to study the distribution, impact and management of invasive grasses in the Western U.S. The cooperative nature of this proposed project lends great power across a large geography to accomplish the objectives. Formation of a Multistate Research Project will facilitate co-created experimental design and implementation among states to better elucidate regionally-specific differences in ecology and treatment efficacy and patterns that are consistent across ecoregions that may be broadly applicable. This project will improve communication, help guide research, and broaden the geographic range of research projects. The outcomes of collaborative research will help stakeholders across the west manage invasive grasses more effectively. This group will meet annually to discuss research, coordinate research to provide preliminary data to secure grant funding, and set future research priorities focused on ecology and management of invasive grasses in rangelands.

Related, Current and Previous Work

The most similar western regional Multistate Project is WERA77 – Managing Invasive Weeds in Wheat. While some of the species of focus overlap, the proposed WDC will focus on rangelands, forests, and natural areas – all sufficiently different from wheat production systems that a different approach and ecological underpinning for invasive grass management is needed. Additionally, management practices in wheat systems are often not available or incompatible with management regimes in natural rangeland ecosystems.

Objectives

1. Assemble a group which will include university research and extension personnel to set research priorities to address invasive grass issues in the Western U.S.
   
2. Provide a preliminary evaluation of the impact of introduced annual grasses on other vegetation in rangelands across the region using existing data.
   
3. Evaluate invasive grass ecology and response to management across the western U.S. to explore patterns in efficacy and consistency of results.
   
4. Evaluate effects of invasive grasses and their management on plant communities and other taxonomic groups (e.g. soil microbiome, wildlife species).
   
5. Assess utility of rapidly-changing technologies (i.e. remote sensing data) to improve detection of infested areas and response to management.
   
6. Develop and share educational materials and programs related to research findings about invasive grass ecology and management.
   

Methods

The Ecology and Management of Invasive Grasses in Western Rangelands Multistate Research Project will meet annually to discuss and coordinate research activities related to invasive grasses in western US rangelands and to review and develop educational materials for stakeholders. The group will conduct similar studies, then share and analyze the data to provide results that are broadly applicable to management decisions throughout the west. Additionally, group members will seek to identify new opportunities to expand the impact of their work.

Knowledge generated individually and cooperatively from objectives 2 through 5 will be shared among members of this group to meet objective 6. To increase efficiency, our annual meetings will coincide with the Western Society of Weed Science (WSWS) annual meetings. Co-locating with WSWS will provide additional opportunities to include ad-hoc members for discussions and to engage graduate students in the activities of this group moving forward.

Measurement of Progress and Results

Outputs

• Inventory of invasive grass impacts to western ecosystems.
• Analyzed data from repeated invasive grass control studies.
• Analyzed results from remote sensing evaluations.

Outcomes or Projected Impacts

• Stronger relationships among scientists and educators working with invasive grasses in rangeland ecosystems, leading to increased cooperation across geographic boundaries.
• Improved quality and quantity of information related to ecology and management of invasive grasses in rangelands across the western US.
• Work from this partnership will improved decision-making capacity for land managers working to mitigate negative ecological and economic impacts of invasive grasses in rangelands.
• Regional education efforts will further develop a sense of community while empowering land managers to collaborate across state lines when developing landscape-scale invasive grass management programs.
• Technical bulletins, popular press materials, and web-based outreach will provide land managers with information to aid their efforts to manage invasive grasses in rangelands.

Milestones

(2024):Collect or consolidate current evaluation of invasive grass impacts on plant communities.

(0):Conduct and evaluate invasive grass studies yearly as new research objectives arise.

(0):Develop at least one cooperative educational material and deliver one educational program per year.

Projected Participation

View Appendix E: Participation

Outreach Plan

To improve public understanding of regional patterns and processes related to ecology and management of invasive grasses in rangeland systems, we will develop and disseminate outreach/extension programs. Our target audiences will include producers, agency personnel, extension personnel, policymakers, land managers, and other scientists. Examples of coordinated outreach/extension efforts include: 1) fact sheets, technical bulletins, and news releases focused on i) invasive grass ecology and management, and ii) resilience and restoration of desired species, 2) cooperative development of best management practices (BMP) recommendations for assessment, treatment, and monitoring of vegetation and other ecosystem attributes for projects where reducing invasive grasses and increasing desired species is a goal, 3) field days and ag professional meetings, 4) web-publication of results, and 5) if appropriate, webinars and other distance learning approaches. These outputs will be targeted toward improving invasive grass management and communicating information about broad-reaching impacts of invasive grasses and their management.

Organization/Governance

Officers will consist of a Chair, Chair-elect, and Secretary, which will be elected by majority vote and will serve two-year, rotating terms. Leadership positions will rotate, with the Chair-elect becoming Chair and a new Chair-elect and Secretary be voted in when necessary at the appropriately-timed annual meeting. Ad-hoc committees will be convened, as necessary, to address specific topics or issues.

Literature Cited

Buerdsell, SL, Milligan, BG and Lehnhoff, EA. 2021. Invasive plant benefits a native plant through plant-soil feedback but remains the superior competitor. Neobiota 64:119-136.

Creutzburg, M.K., A. C. Olsen, M. A. Anthony, J. D. Maestas, J. B. Cupples, N. R. Vora, and B. W. Allred. 2022. A geographic strategy for cross-jurisdictional, proactive management of invasive annual grasses in Oregon. Rangelands. https://doi.org/10.1016/j.rala.2021.12.007

Custer, G. F., & van Diepen, L. T. (2020). Plant Invasion Has Limited Impact on Soil Microbial α-                    Diversity: A Meta-Analysis. Diversity, 12(3), 112. https://doi.org/10.3390/d12030112.

Jones, M.O., D.E. Naugle, D. Twidwell, D.R. Uden, J.D. Maestas, and B.W. Allred. 2020. Beyond inventories: Emergence of a new era in rangeland monitoring. Rangeland Ecology and Management 73:577-583.

Western Governors Association (WGA). 2020. A toolkit for invasive annual grass management in the West. https://westgov.org/images/editor/FINAL_Cheatgrass_Toolkit_July_2020.pdf.

Attachments

Land Grant Participating States/Institutions

ID, MT, NM, WY

Non Land Grant Participating States/Institutions

University of Idaho