Invasive plants are a serious problem worldwide. Plant invasions cause damage to agricultural and natural ecosystems, and contribute to loss of biological diversity. They are difficult to predict, prevent, and control. The Poaceae or grass family contains many species that have been introduced into areas outside of their native ranges and have become invasive. Brome grasses are a group of C3 grasses that grow primarily in temperate regions. A number of brome grasses have been introduced into the North America, sometimes accidentally, and sometimes for use as hay and forage, or for other purposes. Introduced brome grasses display varying levels of invasiveness.
In conjunction with a research project focusing on invasive brome grasses in the western United States, I developed a database that contains information about traits of brome grasses, and about their interactions with biotic and abiotic features of their native and introduced ranges. The database contains information about over 150 species and is designed both to support research into the causes and effects of plant invasions, and to provide information useful for anyone dealing with the use, management, and control of brome grasses. It is hosted on the Great Basin Research and Management Project website at http://greatbasin.wr.usgs.gov/GBRMP/bromus/bromus.html.
I used the data in the database to look for patterns of invasion. Correlations were found between invasiveness (defined as wide distribution outside of the native range combined with weediness), and taxonomic section, seed awn length, polyploidy, human use and availability of cultivars. Annual brome grasses have been widely introduced into new regions around the world and have a high probability of being destructive agricultural, ruderal, and environmental weeds. Long awn length is correlated with invasiveness, especially in annual species. Perennial brome grasses generally remain confined to their native regions unless they are cultivated for hay, forage, or revegetation. Once introduced, perennial bromes can escape cultivation and damage natural communities. The few invasive perennial species are polyploid, while invasive annual species may be diploid or polyploid. Invasiveness in brome species is associated with human activities including habitat disruption, agriculture, grazing, and use for revegetation. Climate change and habitat disruption are likely to change the way brome grasses invade. Most research on brome grasses focuses on highly invasive species, and information about less-invasive and non-invasive species is limited. Collection of information about all brome species in a central location facilitates comparisons among species, and provides data that can be used for modeling, prediction, management and control of brome grass invasions.
|Advisor:||Brown, Cynthia S.|
|Commitee:||Steingraeber, David, Ward, Sarah|
|School:||Colorado State University|
|Department:||Ecology (Graduate Degree Program)|
|School Location:||United States -- Colorado|
|Source:||MAI 52/01M(E), Masters Abstracts International|
|Subjects:||Ecology, Environmental Studies, Plant sciences|
|Keywords:||Bromus, Dispersal, Human use, Invasion, Life span, Ploidy|
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