Taxonomic name: Bromus tectorum (Linnaeus)
Synonyms: Anisantha tectorum (L.), Bromus tectorum L. var. glabratus, Bromus tectorum L. var. hirsutus, Bromus tectorum L. var. nudus
Common names: broncograss (English), cheat grass (English), cheatgrass brome (English), downy brome (English), downy chess (English), drooping brome (English), early chess (English), military grass (English), Mormon oats (English), slender chess (English), thatch bromegrass (English)
Organism type: grass
The invasive grass Bromus tectorum is troublesome to farmers and many ecosystems. It usually thrives in disturbed areas preventing natives from returning to the area. Disturbance such as overgrazing, cultivation, and frequent fires encourage invasion. Once established the natives cannot compete and the whole ecosystem is altered.
Bromus tectorum is a winter annual. The seedlings are bright green and have hairy leaves. Stems are erect and slender and may also be slightly hairy. The stem tips, where the seeds are located, droop slightly. The grass has an overall fine, soft appearance and typically grows 50-60cm tall. As it dries out it begins to turn purplish in colour. B. tectorum is a straw-like colour when completely dry, which is when it is most flammable.
agricultural areas, range/grasslands, ruderal/disturbed, scrub/shrublands, urban areas
Bromus tectorum is predominately found in disturbed sagebrush grassland ecosystems but is also found in undisturbed shrub-steppe and intermountain ranges. It spreads into areas that are overgrazed, cultivated, frequently burned or otherwise disturbed. B. tectorum prefers full sunlight and does not grow well under the forest canopy.
As Bromus tectorum is such a dry plant, it increases the frequency of fires in an area. This causes declines in natives that are accustomed to less frequent fires while B. tectorum flourishes. The more frequent fires cause a loss of topsoil and nutrients, which alters the make up of the soil and therefore the ecosystem. On the other hand, B. tectorum may stabilise the soil from wind and water erosion (Carpenter et. al, 1999). In Russia the impacts of B. tectorum are less serious, even in regions with similar precipitation to the Great Basin of the United States. While it will rapidly and completely dominate disturbed sites in Russia, these will often revert to more diverse, stable communities within three to five years of the invasion. It has been suggested that this is due to the more diverse natural communities present in these affected regions of Russia, and the greater proportion of summer rainfall that benefits perennials rather than winter annuals such as B. tectorum (Clark, 2001).North American B. tectorum invasions cost wheat farmers in the western United States and Canada US$350-375 million in control and loss yields each year. Although used by some farmers as feed, it can cause serious damage to livestock's mouth, intestines, nostrils, and eyes. In North America it competes with native shrubs and perennial grasses and totally alters the ecosystem.
Bromus tectorum is used as feed for many kinds of livestock, and it is also eaten by mule deer, pronghorn, elk, small mammals, upland game birds, and small non-game birds. It provides habitat to many small mammals and birds. B. tectorum is sometimes planted to decrease erosion.
Native range: B. tectorum is native to southern Europe and southwestern Asia.
Known introduced range: It has invaded most of Europe, southern Russia, western and central Asia, Japan, South Africa, Australia, New Zealand, Iceland, Greenland, Canada and the United States.
Introduction pathways to new locations
Agriculture: Used for livestock forage.
Local dispersal methods
On animals (local):
Preventative measures: It is important to avoid disturbance caused by overgrazing, cultivation and frequent fires as they encourage invasion.
Physical: Where infestation is light, burning is not recommended, however, hand pulling can be effective in these areas. Care must be taken to remove most of the root, or it will grow back. Treatment should be followed by re-seeding of perennials, or else B. tectorum and other weeds will re-establish in the newly disturbed area. Follow-up treatment is required.
Biological: In North America, grasses, such as Crested Wheatgrass, have been planted to compete with B. tectorum. This has been successful in some cases.
Integrated management: Mowing or cutting is not recommended. Burning and herbicide application are effective control measures, but to ensure selective control, they should be performed in early spring when non-target species are dormant. However B. tectorum fires can burn very hot and move very quickly so care should be taken (Beck pers. comm., in Carpenter et. al, 1999).
Bromus tectorum prefers potassium rich soil.
Bromus tectorum is self-pollinating. Seeds are dispersed by wind and animals.
High temperatures and light intensities inhibit germination, however, seeds have been known to germinate following 11 years of storage under dry conditions. Once germination occurs, the roots develop quickly and are usually well developed by spring.
Reviewed by: Dr. Petra Lowe. Department of Forest Sciences, Colorado State University, Fort Collins. USA
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Friday, 30 December 2005