Cheatgrass and Medusahead Active
Invasive annual grasses, such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), are one of the most significant stressors to rangeland ecosystems in the western U.S. Their expansion and dominance across this area are the most damaging ecosystem agents on this iconic landscape.
Many invasive plants thrive in disturbed areas and are easily spread through various pathways and vectors. In the western U.S., disturbed landscape can take the form of areas changed by human development, improper grazing, and burned by wildfire. Roads and trails, and the vehicles that travel them, transmission corridors, and fuel breaks all serve as pathways and vectors that help spread these unwanted invaders. Once an invasive plant becomes established in an area, it can quickly spread across the landscape. Invasive plant species can become ecologically dominant, creating near-monocultures that result in reduced wildlife habitat, recreational opportunities, livestock forage, and altered fire regimes. Even after landscape disturbances are removed from areas dominated by these plants, these invasive annual grasses can remain the dominant plant.
Cheatgrass originated in Europe or Eurasia and medusahead in the Mediterranean region. Both were introduced to the U.S. in the mid- to late-1800's as a contaminant in seed and straw. Both species germinate in the fall and early spring, grow rapidly and in high numbers making them highly competitive with native species.
Plants native to the sagebrush landscape may not recover from disturbances that allow invasive annual grasses to over-run them, even decades later. In these areas, elimination of invasive annual grasses is very difficult because the limited number of remaining native plants are unable to produce seeds and seedlings that can compete with these invasive annual grasses. In addition, the thick thatch produced by annual grasses kills biological soil crusts (lichens, mosses and cyanobacteria) that once filled the soil interspaces between the native grasses and shrubs.
The conversion of a diverse native ecosystem to simple invasive grass-dominated ecosystems degrades the ecosystem processes leading to soil erosion, less water in the soil for plant growth, and changes in nutrient cycling, making a less productive land that is much harder to restore to what it was before the invasion.
Land managers are tasked with controlling cheatgrass and medusahead, but resources are limited for invasive plant management. They face difficult decisions on how to use their limited resources. Do they target high-risk pathways and vectors of invasion for efficiency, focus on specific invasive plant patches that are feasible to control, or treat the periphery of a large invasion to slow and contain the spread? Innovative approaches that capitalize on the targeted ecosystem’s resilience to disturbance and resistance to invasive plant invasion is needed to achieve long-term ecosystem conservation and restoration goals for invasive plant-dominated landscapes.
Researchers at the USGS have and continue to develop a wide variety of tools and systems, and answer questions, that help tribal, federal, state, industry, and private land managers design and implement sustainable rangeland practices along with effective restoration and rehabilitation projects. Studies focus on finding ways to control cheatgrass and medusahead through use of herbicides, soil bacteria, and targeted grazing. On-going research also answers questions about the resistance of an ecosystem to an invasive plant, including the suitability of the ecosystem’s climate and soils for establishment and persistence of the invasive plant, and the capacity of the native plant community to prevent increases in the invasive plant’s population through factors such as competition, herbivory, and ability of native plants, including biological soil crusts, to adapt to environmental conditions. They develop solutions to help land managers bolster or support the ecosystem's resilience, or ability to bounce back from a disturbance.
Notable contributions include:
Exotic Brome-Grasses in the Western U.S. Edited and contributed to the authoritative source of information on exotic annual Bromus in arid and semi-arid ecosystems of the western U.S.
Indicators of Rangeland Health. Development of the best, most consistent, and comparable method to determine rangeland health. This method is widely used by multiple land management agencies and highly
valued by ranchers.
Right Seed at the Right Place and Time. Tests of seed sources used in BLM restoration efforts changed seed transfer guidelines and enhanced seeding success. Our data helps the BLM, the largest purchaser of
wildland seed globally, buy the right kind and amount of seed.
Conservation Efforts Database. Constructed a data system that helped the USFWS determine if stakeholder conservation efforts were enough to avoid an Endangered Species Act listing of the Greater sage-grouse.
Restoration of biological soil crusts. Tests of species for restoration, impacts of grazing and fire are of interest to BLM, USFWS, and USFS managers to enhance restoration successes.
Browse the Publications and Data and Tools tabs to find USGS publications related to invasive annual grasses.
Check out the News tab for plain language descriptions of USGS studies and publications.
Click the Multimedia tab for pictures and maps.
Visit the team pages for the scientists working on invasive annual grasses.
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
Below are downloadable images related to cheatgrass and medusahead.
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
A Chronosequence Feasibility Assessment of Emergency Fire Rehabilitation Records within the Intermountain Western United States - Final Report to the Joint Fire Science Program - Project 08-S-08
Environmental and climatic variables as potential drivers of post-fire cover of cheatgrass (Bromus tectorum) in seeded and unseeded semiarid ecosystems
Defoliation effects on Bromus tectorum seed production: Implications for grazing
Biotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington
Red brome (Bromus rubens subsp. madritensis) in North America: Possible modes for early introductions, subsequent spread
Effects of soil amendments on germination and emergence of downy brome (Bromus tectorum) and Hilaria jamesii
Rangeland health attributes and indicators for qualitative assessment
Comparison of soil bacterial communities in rhizospheres of three plant species and the interspaces in an arid grassland
Field soil aggregate stability kit for soil quality and rangeland health evaluations
Soil biota in an ungrazed grassland: Response to annual grass (Bromus tectorum) invasion
Crested wheatgrass-cheatgrass seedling competition in a mixed-density design
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
Land Treatment Exploration Tool
The Land Treatment Exploration Tool is designed for resource managers to use when planning land treatments. The tool provides useful summaries of environmental characteristics of planned treatment areas and facilitates adaptive management practices by comparing those characteristics to other similar treatments within a specified distance or area of interest. Provisional Software.
Plain language descriptions for some related USGS products and publications.
New Invasive Annual Grass Book Addresses Critical Questions for the Western U.S.
- Overview
Invasive annual grasses, such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), are one of the most significant stressors to rangeland ecosystems in the western U.S. Their expansion and dominance across this area are the most damaging ecosystem agents on this iconic landscape.
Many invasive plants thrive in disturbed areas and are easily spread through various pathways and vectors. In the western U.S., disturbed landscape can take the form of areas changed by human development, improper grazing, and burned by wildfire. Roads and trails, and the vehicles that travel them, transmission corridors, and fuel breaks all serve as pathways and vectors that help spread these unwanted invaders. Once an invasive plant becomes established in an area, it can quickly spread across the landscape. Invasive plant species can become ecologically dominant, creating near-monocultures that result in reduced wildlife habitat, recreational opportunities, livestock forage, and altered fire regimes. Even after landscape disturbances are removed from areas dominated by these plants, these invasive annual grasses can remain the dominant plant.
Cheatgrass originated in Europe or Eurasia and medusahead in the Mediterranean region. Both were introduced to the U.S. in the mid- to late-1800's as a contaminant in seed and straw. Both species germinate in the fall and early spring, grow rapidly and in high numbers making them highly competitive with native species.
Plants native to the sagebrush landscape may not recover from disturbances that allow invasive annual grasses to over-run them, even decades later. In these areas, elimination of invasive annual grasses is very difficult because the limited number of remaining native plants are unable to produce seeds and seedlings that can compete with these invasive annual grasses. In addition, the thick thatch produced by annual grasses kills biological soil crusts (lichens, mosses and cyanobacteria) that once filled the soil interspaces between the native grasses and shrubs.
The conversion of a diverse native ecosystem to simple invasive grass-dominated ecosystems degrades the ecosystem processes leading to soil erosion, less water in the soil for plant growth, and changes in nutrient cycling, making a less productive land that is much harder to restore to what it was before the invasion.
Land managers are tasked with controlling cheatgrass and medusahead, but resources are limited for invasive plant management. They face difficult decisions on how to use their limited resources. Do they target high-risk pathways and vectors of invasion for efficiency, focus on specific invasive plant patches that are feasible to control, or treat the periphery of a large invasion to slow and contain the spread? Innovative approaches that capitalize on the targeted ecosystem’s resilience to disturbance and resistance to invasive plant invasion is needed to achieve long-term ecosystem conservation and restoration goals for invasive plant-dominated landscapes.
Researchers at the USGS have and continue to develop a wide variety of tools and systems, and answer questions, that help tribal, federal, state, industry, and private land managers design and implement sustainable rangeland practices along with effective restoration and rehabilitation projects. Studies focus on finding ways to control cheatgrass and medusahead through use of herbicides, soil bacteria, and targeted grazing. On-going research also answers questions about the resistance of an ecosystem to an invasive plant, including the suitability of the ecosystem’s climate and soils for establishment and persistence of the invasive plant, and the capacity of the native plant community to prevent increases in the invasive plant’s population through factors such as competition, herbivory, and ability of native plants, including biological soil crusts, to adapt to environmental conditions. They develop solutions to help land managers bolster or support the ecosystem's resilience, or ability to bounce back from a disturbance.
Notable contributions include:
Exotic Brome-Grasses in the Western U.S. Edited and contributed to the authoritative source of information on exotic annual Bromus in arid and semi-arid ecosystems of the western U.S.
Indicators of Rangeland Health. Development of the best, most consistent, and comparable method to determine rangeland health. This method is widely used by multiple land management agencies and highly
valued by ranchers.Right Seed at the Right Place and Time. Tests of seed sources used in BLM restoration efforts changed seed transfer guidelines and enhanced seeding success. Our data helps the BLM, the largest purchaser of
wildland seed globally, buy the right kind and amount of seed.Conservation Efforts Database. Constructed a data system that helped the USFWS determine if stakeholder conservation efforts were enough to avoid an Endangered Species Act listing of the Greater sage-grouse.
Restoration of biological soil crusts. Tests of species for restoration, impacts of grazing and fire are of interest to BLM, USFWS, and USFS managers to enhance restoration successes.
Browse the Publications and Data and Tools tabs to find USGS publications related to invasive annual grasses.
Check out the News tab for plain language descriptions of USGS studies and publications.
Click the Multimedia tab for pictures and maps.
- Science
Visit the team pages for the scientists working on invasive annual grasses.
- Data
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
- Multimedia
Below are downloadable images related to cheatgrass and medusahead.
- Publications
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
Filter Total Items: 35A Chronosequence Feasibility Assessment of Emergency Fire Rehabilitation Records within the Intermountain Western United States - Final Report to the Joint Fire Science Program - Project 08-S-08
Department of the Interior (DOI) bureaus have invested heavily (for example, the U.S. Bureau of Land Management (BLM) spent more than $60 million in fiscal year 2007) in seeding vegetation for emergency stabilization and burned area rehabilitation of non-forested arid lands over the past 10 years. The primary objectives of these seedings commonly are to (1) reduce the post-fire dominance of non-naAuthorsKevin C. Knutson, David A. Pyke, Troy A. Wirth, David S. Pilliod, Matthew L. Brooks, Jeanne C. ChambersEnvironmental and climatic variables as potential drivers of post-fire cover of cheatgrass (Bromus tectorum) in seeded and unseeded semiarid ecosystems
Cheatgrass, a non-native annual grass, dominates millions of hectares in semiarid ecosystems of the Intermountain West (USA). Post-fire invasions can reduce native species diversity and alter ecological processes. To curb cheatgrass invasion, land managers often seed recently burned areas with perennial competitor species. We sampled vegetation within burned (19 years post-fire) and nearby unburneAuthorsD.J. Shinneman, W.L. BakerDefoliation effects on Bromus tectorum seed production: Implications for grazing
Cheatgrass (Bromus tectorum L.) is an invasive annual grass that creates near-homogenous stands in areas throughout the Intermountain sagebrush steppe and challenges successful native plant restoration in these areas. A clipping experiment carried out at two cheatgrass-dominated sites in eastern Oregon (Lincoln Bench and Succor Creek) evaluated defoliation as a potential control method for cheatgrAuthorsK. Hempy-Mayer, D.A. PykeBiotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington
We studied lichen and bryophyte soil crust communities in a large public grazing allotment within a sagebrush steppe ecosystem in which the biotic soil crusts are largely intact. The allotment had been rested from grazing for 12 years, but experienced an extensive series of wildfires. In the 350, 4 x 0.5 m plots, stratified by topographic position, we found 60 species or species groups that can beAuthorsJeanne Ponzetti, B. McCune, David A. PykeRed brome (Bromus rubens subsp. madritensis) in North America: Possible modes for early introductions, subsequent spread
Although invasions by exotic plants have increased dramatically as human travel and commerce have increased, few have been comprehensively described. Understanding the patterns of invasive species’ spread over space and time will help guide management activities and policy. Tracing the earliest appearances of an exotic plant reveals likely sites of introduction, paving the way for genetic studiesAuthorsL. F. SaloEffects of soil amendments on germination and emergence of downy brome (Bromus tectorum) and Hilaria jamesii
Downy brome is an introduced Mediterranean annual grass that now dominates millions of hectares of western U.S. rangelands. The presence of this grass has eliminated many native species and accelerated wildfire cycles. The objective of this study was to identify soil additives that allowed germination but inhibited emergence of downy brome, while not affecting germination or emergence of the nativAuthorsJ. Belnap, S. K. Sherrod, M. E. MillerRangeland health attributes and indicators for qualitative assessment
Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for asseAuthorsDavid A. Pyke, Jeffrey E. Herrick, Patrick Shaver, Mike PellantComparison of soil bacterial communities in rhizospheres of three plant species and the interspaces in an arid grassland
Soil bacteria are important contributors to primary productivity and nutrient cycling in arid land ecosystems, and their populations may be greatly affected by changes in environmental conditions. In parallel studies, the composition of the total bacterial community and of members of the Acidobacterium division were assessed in arid grassland soils using terminal restriction fragment length polymoAuthorsCheryl R. Kuske, Lawrence O. Ticknor, Mark E. Miller, John M. Dunbar, Jody A. Davis, Susan M. Barns, Jayne BelnapField soil aggregate stability kit for soil quality and rangeland health evaluations
Soil aggregate stability is widely recognized as a key indicator of soil quality and rangeland health. However, few standard methods exist for quantifying soil stability in the field. A stability kit is described which can be inexpensively and easily assembled with minimal tools. It permits up to 18 samples to be evaluated in less than 10 min and eliminates the need for transportation, minimizingAuthorsJ. E. Herrick, W. G. Whitford, A. G. de Soyza, J. W. Van Zee, K. M. Havstad, C. A. Seybold, M. WaltonSoil biota in an ungrazed grassland: Response to annual grass (Bromus tectorum) invasion
Bromus tectorum is an exotic annual grass that currently dominates many western U.S. semi-arid ecosystems, and the effects of this grass on ecosystems in general, and soil biota specifically, are unknown. Bromus recently invaded two ungrazed and unburned perennial bunchgrass communities in southeastern Utah. This study compared the soil food-web structure of the two native grassland associations (AuthorsJayne Belnap, Susan L. PhillipsCrested wheatgrass-cheatgrass seedling competition in a mixed-density design
Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. eAuthorsMark G. Francis, David A. Pyke - Web Tools
If you are unable to access a product or publication online, you can request a copy by sending an email with your contact information and the publication's citation to fresc_outreach@usgs.gov or call (541) 750-1030.
Land Treatment Exploration Tool
The Land Treatment Exploration Tool is designed for resource managers to use when planning land treatments. The tool provides useful summaries of environmental characteristics of planned treatment areas and facilitates adaptive management practices by comparing those characteristics to other similar treatments within a specified distance or area of interest. Provisional Software.
- News
Plain language descriptions for some related USGS products and publications.
New Invasive Annual Grass Book Addresses Critical Questions for the Western U.S.
BOISE, Idaho — Bromus species – such as cheatgrass – are exotic annual grasses that have become the dominant annual grasses in the western hemisphere. Their spread and impacts across the western U.S. continue despite the many attempts by land managers to control these species.Filter Total Items: 16 - Partners