historical records of cheatgrass Bromus tectorum invasion in North American sagebrush-steppe Sumanta Bagchi*, David D. Briske, Brandon T. Bestelmeyer and X. Ben Wu Department of Ecosystem Science and Management, Texas A&M University, 2138 TAMU, College Station, TX 77843, USA; USDA-ARS, Jornada Experimental Range and Jornada Basin LTER, New Mexico State University, MSC 3JER, Box 30003, Las Cruce...

M any natural landscapes have undergone dramatic permanent alterations as a result of human activities, including conversion to cultural landscapes; such changes are readily observed and understood. However, extensive ecological change can also occur in regional landscapes that are maintained in a seminatural state, changes that go largely unrecognized because the regional landscape retains an ...

Throughout the western United States, the invasive annual grass, medusahead (Taeniatherum caputmedusae L. Nevski), is rapidly invading grasslands once dominated by native perennial grasses, such as bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A). It is also invading grasslands dominated by less undesirable invasive annual grasses, especially cheatgrass (Bromus tectorum L.). Understandi...

The invasive grass Bromus tectorum fuels fires, displaces native species, and reduces wildlife habitat on sagebrush steppe throughout the western United States. Recently, it has spread from the Great Basin Desert into higher elevations of the eastern Sierra Nevada, where it coexists with natives but has not yet altered fire regimes. We evaluated effects of a springtime water pulse (+10 mm) in a...

Worldwide, exotic invasive grasses have caused numerous ecosystem perturbations. Rangelands of the western USA have experienced increases in the size and frequency of wildfires largely due to invasion by the annual grass Bromus tectorum. Rehabilitation of invaded rangelands is difficult; but long-term success is predicated on establishing healthy and dense perennial grass communities, which sup...

Elevated CO2 and warming may alter terrestrial ecosystems by promoting invasive plants with strong community and ecosystem impacts. Invasive plant responses to elevated CO2 and warming are difficult to predict, however, because of the many mechanisms involved, including modification of phenology, physiology, and cycling of nitrogen and water. Understanding the relative and interactive importanc...

Abiotic factors have a strong infl uence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromus occurrence. At the more local scale, soil characteristics and climate infl uence distribution, cover, and performance. In hot, dry, summerrainfall-dominated deserts (Sonoran, Chihuahuan), little or no Bromus is ...

this research was carried out to investigate allelopathic effect of peganum harmala on seed germination of bromus tectorum. aboveground and underground tissues of peganum harmala in addition to its seeds were collected from bijar rangelands. collected materials of root, leaves, stem, seeds and a complex of mentioned parts were dried and powder. the research was performed at the greenhouse condi...