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...

Cheatgrass (Bromus tectorum) is an invasive weed in western North America found primarily growing at elevations less than 2200 m. We asked whether cheatgrass is capable of becoming adapted to a marginal habitat, by investigating a population at a high elevation invasion edge. We used a combination of methods, including reciprocal field transplants, controlled environment studies and molecular a...

Cheatgrass (Bromus tectorum) is of growing concern among farmers, ranchers, and researchers in the intermountain west due to its ability to alter rangeland vegetation communities and their associated fire regimes. Quickbird multi-spectral imagery (spatial resolution 2.4 mpp) was used to detect and model cheatgrass presence in southeastern Idaho. Training sites were created using 2003 field data...

Although cheatgrass (Bromus tectorum) has been widely distributed across western rangelands for >70 years, the full ecologic and economic impacts of this non-native invasive plant have not yet occurred. Unfortunately, several independent lines of evidence indicate that the rate at which acreage becomes infested with cheatgrass is increasing rapidly. Furthermore, the invasion and spread of a num...

Changes in the species composition of biotic communities may alter patterns of natural selection occurring within them. Native perennial grass species in the Intermountain West are experiencing a shift in the composition of interspecific competitors from primarily perennial species to an exotic, annual grass. Thus traits that confer an advantage to perennial grasses in the presence of novel ann...

Title of Thesis: DYNAMIC STUDY OF HEAVY METAL FATES IN BIORETENTION SYSTEMS Xueli Sun, Master of Science, 2004 Thesis directed by: Professor Allen P. Davis Department of Civil and Environmental Engineering Bioretention is a best management practice (BMP). In this research, pot prototypes filled with bioretention media were built to simulate the conditions of natural growth of three grasses: Pan...

Allen P.S., Meyer S.E., Beckstead J. (2013): A predictive model for soil seed bank outcomes in the Pyrenophora semeniperda–Bromus tectorum pathosystem. Plant Protect. Sci., 49 (Special Issue): S21–S24. Pyrenophora semeniperda is abundant in soil seed banks of Bromus tectorum, where it kills a fraction of seeds throughout the year. The pathogen engages in a race with host seeds for endosperm res...

Two new phytotoxic sesquiterpenoid acids, named pyrenophoric acids B and C, were isolated together with the related pyrenophoric and abscisic acids from solid Bromus tectorum (cheatgrass) seed culture of the seed pathogen Pyrenophora semeniperda. This fungus has been proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum), a Eurasian annual grass that has become invasive in r...