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Full-Text Articles in Life Sciences
Cheatgrass Die-Off Phenomena: What Are The Short And Long Term Recovery Factors Of Bromus Tectorum Stand Failure?, Joshua Alan Nicholson
Cheatgrass Die-Off Phenomena: What Are The Short And Long Term Recovery Factors Of Bromus Tectorum Stand Failure?, Joshua Alan Nicholson
Theses and Dissertations
Observations of Bromus tectorum L. (cheatgrass or downy brome) monocultures have shown that populations are susceptible to stand die-off or replacement failures. Die-offs, where the seed bank from the previous year fails to emerge, occurs in cheatgrass stands and it is unclear the trigger or cause. The fungus Fusarium has been identified in plant and seed samples from die-offs and may drive die-off activity through pathogenicity. Die-off recovery may take several years but cheatgrass populations eventually reestablish. The purpose of our study was to determine whether Fusarium is a potential player in a die-off, and understand how die-offs recover after …
Identification Of The Infection Route Of A Fusarium Seed Pathogen Into Non-Dormant Bromus Tectorum Seeds, Janalynn Franke
Identification Of The Infection Route Of A Fusarium Seed Pathogen Into Non-Dormant Bromus Tectorum Seeds, Janalynn Franke
Theses and Dissertations
The genus Fusarium has a wide host range and causes many different forms of plant disease. These include seed rot and seedling blight diseases of cultivated plants. The Fusarium-caused diseases of wild plants are less well-known. In this study we examined Fusarium sp. n-caused disease development on non-dormant seeds of the important rangeland weed Bromus tectorum as part of broader studies of the phenomenon of stand failure or ‘die-off’ in this annual grass. We previously isolated an undescribed species in the Fusarium tricinctum species complex from die-off soils and showed that it is pathogenic on seeds. It can cause high …
Response Of Conifer-Encroached Shrublands In The Great Basin To Prescribed Fire And Mechanical Treatments, Richard F. Miller, Jaime Ratchford, Bruce A. Roundy, Robin J. Tausch, April Hulet, Jeanne C. Chambers
Response Of Conifer-Encroached Shrublands In The Great Basin To Prescribed Fire And Mechanical Treatments, Richard F. Miller, Jaime Ratchford, Bruce A. Roundy, Robin J. Tausch, April Hulet, Jeanne C. Chambers
Articles
In response to the recent expansion of piñon and juniper woodlands into sagebrush-steppe communities in the northern Great Basin region, numerous conifer-removal projects have been implemented, primarily to release understory vegetation at sites having a wide range of environmental conditions. Responses to these treatments have varied from successful restoration of native plant communities to complete conversion to nonnative invasive species. To evaluate the general response of understory vegetation to tree canopy removal in conifer-encroached shrublands, we set up a region-wide study that measured treatment-induced changes in understory cover and density. Eleven study sites located across four states in the Great …
Hydrothermal Time Analysis Of Pyrenophora Semeniperda, Heather Finch, Dr. Phil Allen
Hydrothermal Time Analysis Of Pyrenophora Semeniperda, Heather Finch, Dr. Phil Allen
Journal of Undergraduate Research
Invasive species such as Bromus tectorum, commonly known as cheatgrass, occupy over 40 million hectares of land within the interior portion of the United States. The naturally occurring pathogen Pyrenophora semeniperda has been discovered to kill the seeds of this invasive species. We believe that it could be used as a potential biocontrol within the field. But like many pathogens, it has a catch. P. semeniperda preferentially kills dormant seeds.
Wet-Thermal Time And Plant Available Water In The Seedbeds And Root Zones Across The Sagebrush Steppe Ecosystem Of The Great Basin, Nathan Lyle Cline
Wet-Thermal Time And Plant Available Water In The Seedbeds And Root Zones Across The Sagebrush Steppe Ecosystem Of The Great Basin, Nathan Lyle Cline
Theses and Dissertations
Following wildfires, plant materials are direct-seeded to limit erosion and annual weed invasion. Seedlings often fail to establish because selected plant materials are not always well adapted to local soil moisture and temperature conditions. In an effort to help improve plant materials selection and to evaluate sites potential revegetation, we have worked toward developing methodology to predict germination and root growth based on site specific soil moisture and temperature conditions. First, we characterized the seedbed environment of 24 sagebrush (Artemisia spp.) steppe sites throughout the Intermountain West to determine the wet-thermal time of five temperature ranges relevant to germination …
Genetic Variation And Adaptation In The Invasive Weed Bromus Tectorum And Its Associated Pathogens Pyrenophora Semeniperda And Ustilago Bullata, Craig E. Coleman
Genetic Variation And Adaptation In The Invasive Weed Bromus Tectorum And Its Associated Pathogens Pyrenophora Semeniperda And Ustilago Bullata, Craig E. Coleman
Journal of Undergraduate Research
The objectives of this proposal were as follows: 1. Develop single nucleotide polymorphism (SNP) markers for Bromus tectorum (cheatgrass) for use in determining population structure and mapping adaptive traits. 2. Complete a full genome sequence of the Pyrenophora semeniperda fungal pathogen to identify genes encoding important traits related to its pathogenicity on cheatgrass seeds. 3. Complete a full genome sequence of the Ustilago bullata head smut to facilitate identification of virulence genes associated with its pathogenicity on cheatgrass.
Development Of Cheatgrass Microsatellite Markers, Alisa Paulsen, Dr. Daniel Fairbanks
Development Of Cheatgrass Microsatellite Markers, Alisa Paulsen, Dr. Daniel Fairbanks
Journal of Undergraduate Research
In the Western United States, cheatgrass (Bromus tectorum, introduced from Eurasia) is often considered to be an undesirable, invasive weed. When cheatgrass is introduced into an area, it can rapidly establish itself as the dominant species, inhibiting reestablishment of native plants, competing with important grain crops such as winter wheat, and increasing the frequency of fire.1,2,3 Over the last one-hundred years, cheatgrass has spread so rapidly that it is now a dominant grass in large areas of the United States.
Hydrologic And Erosion Responses To Wildfire Along The Rangeland-Xeric Forest Continuum In The Western Us: A Review And Model Of Hydrologic Vulnerability, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Jan Boll
Hydrologic And Erosion Responses To Wildfire Along The Rangeland-Xeric Forest Continuum In The Western Us: A Review And Model Of Hydrologic Vulnerability, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Jan Boll
Articles
The recent increase in wildfire activity across the rangeland–xeric forest continuum in the western United States has landscape-scale consequences in terms of runoff and erosion. Concomitant cheatgrass (Bromus tectorum L.) invasions, plant community transitions and a warming climate in recent decades along grassland–shrubland–woodland–xeric forest transitions have promoted frequent and large wildfires, and continuance of the trend appears likely if warming climate conditions prevail. These changes potentially increase overall hydrologic vulnerability by spatially and temporally increasing soil exposure to runoff and erosion processes. Plot and hillslope-scale studies demonstrate burning may increase event runoff or erosion by factors of 2–40 over …
Amplified Fragment Length Polymorphism (Aflp) Analysis Of Head Smut Population Diversity, Jennifer Waters, Dr. Mikel R. Stevens
Amplified Fragment Length Polymorphism (Aflp) Analysis Of Head Smut Population Diversity, Jennifer Waters, Dr. Mikel R. Stevens
Journal of Undergraduate Research
Bromus tectorum (cheatgrass), an invasive winter annual weed, displaces native vegetation, invades crops, and fuels rangeland fires across approximately 40 million hectares of the Intermountain West. Most attempts to control the weed have been unsuccessful, leading to a search for a biological control agent. Ustilago bullata, head smut, is a natural species-specific, fungal pathogen of cheatgrass. Despite apparent phenotypic (physical) uniformity in cheatgrass and head smut, susceptibility and virulence, respectively, are variable. These findings led to the hypothesis that genetic variability for susceptibility/pathogenicity exists in the host and pathogen.
Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler
Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler
Green Canyon Environmental Research Area, Logan Utah
Climate change threatens to exacerbate the impacts of invasive species. In temperate ecosystems, direct effects of warming may be compounded by dramatic reductions in winter snow cover. Cheatgrass (Bromus tectorum) is arguably the most destructive biological invader in basins of the North American Intermountain West, and warming could increase its performance through direct effects on demographic rates or through indirect effects mediated by loss of snow. We conducted a two-year experimental manipulation of temperature and snow pack to test whether 1) warming increases cheatgrass population growth rate and 2) reduced snow cover contributes to cheatgrass’ positive response to …