Ecological Assessment of Sagebrush Grasslands in Eastern Wyoming

An understanding of existing ecosystem conditions is necessary for planning efforts that include formulation of landscape conservation goals and implementation strategies. In support of a landscape planning effort for a 946,000-ac mixed-ownership area in eastern Wyoming, we used remote sensing and field sampling to assess existing ecosystem conditions of terrestrial ecological sites. We used SPOT 5, 33-ft (10-m) multi-spectral satellite imagery combined with NRCS ecological sites to create a geographic information system layer of vegetation cover by ecological site. We then integrated the remote sensing information with field data (571 plots) collected from a stratified random design from 2003 through 2005. The integration of the field data with the satellite mapping provided specific information about each terrestrial ecological site including species composition, productivity, structure, and shrub cover. Western wheatgrass was the most dominant species across all of the terrestrial ecological sites followed by big sagebrush, needle and thread, blue grama, annual brome species and to a lesser extent threadleaf sedge, and six weeks fescue. We found species that typically decrease with grazing (for example green needlegrass, bluebunch wheatgrass, Indian ricegrass) to be lacking or entirely absent from plant communities. Introduced species, especially the annual bromes, were prevalent across all ecological sites. Over 55 percent of the terrestrial ecosystems we sampled had greater than five percent relative cover of introduced plant species. Current ecosystem conditions for many wildlife of the area, as identified by our assessment, had generally lower habitat quality than desired and treatments to improve these conditions are planned

Incorporating Historical Ecosystem Diversity into Conservation Planning Efforts in Grass and Shrub Ecosystems

Understanding historical ecosystem diversity and wildlife habitat quality can provide a useful reference for managing and restoring rangeland ecosystems. We characterized historical ecosystem diversity using available empirical data, expert opinion, and the spatially explicit vegetation dynamics model SIMPPLLE (SIMulating Vegetative Patterns and Processes at Landscape ScaLEs) for a landscape of approximately 946,000 ac in eastern Wyoming. We used SIMPPLLE to simulate plant community dynamics as a result of historical disturbance events (for example, fire, bison grazing, and prairie dog activity), climate, and landscape elements (for example, ecological site, proximity to water, and elevation) and their interactions to derive estimates of the historical range of variability for each grass/shrub ecosystem. For each NRCS designated ecological site we defined the historical states that occurred in the presence of grazing by native herbivores and fire, and identified the processes for movements among states within each site. For each historically occurring state within the delineated landscape we determined the mean ac it occupied and the range of variability (in other words, minimum and maximum ac a state occupied). Comparisons of historical grass/shrub ecosystem diversity of the area with existing conditions indicate that there have been significant changes, most notably the lack of representation of ecosystems dominated by grass species that typically decrease with grazing, the widespread presence of introduced species especially annual brome, and alterations to fire regimes. Through comparisons of historical ecosystem diversity with existing conditions, we identified specific plant communities that are underrepresented and in need of restoration to maintain ecosystem diversity and wildlife habitat

Book Review: Guide to Texas Grasses, Robert B. Shaw

Book Review: Guide to Texas Grasses, Robert B. Shaw. Texas A&M University Press, College Station, Texas, USA (2012).The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

The Evolving Role of Women as Rangeland Educators and Researchers in Colleges and Universities and in the Society for Range Management

On the Ground • In the last 30 years, women have increased in SRM membership percentage, which appears to have paralleled the number of women hired into academic positions and women entering the discipline. • Although the history of women as SRM members and rangeland educators is relatively short, the increase seems to reflect that of related disciplines. • Gender demographic changes have increased diversity within the SRM and many academic institutions, enhancing what each offers. • Disproportionately fewer women receiving recognition and advancing to leadership positions within SRM or higher ranks within academia may reflect opportunities for the range profession to address.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

An Introduction to the Special Issue on Pollinators

The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Fire and Nitrogen Effects on Purple Threeawn (Aristida purpurea) Abundance in Northern Mixed-Grass Prairie Old Fields

Purple threeawn (Aristida purpurea Nutt. varieties) is a native grass capable of increasing on rangelands, forming near monocultures, and creating a stable state. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, reducing overall forage quality. Our objectives were to 1) reveal the effects of prescribed fire and nitrogen amendments on purple threeawn abundance and 2) assess nontarget plant response posttreatment. Season of fire (no fire, summer fire, fall fire) and nitrogen addition (0 kg N ha-1, 46 kg N ha-1, and 80 kg N ha-1) were factorially arranged in a completely randomized design and applied to two similar sites in southeastern Montana. We evaluated fire and nitrogen effects on purple threeawn basal cover, relative composition, and current-year biomass one growing season postfire at two sites treated during different years. Spring weather following fire treatments was very different between years and subsequently impacted community response. Initial purple threeawn biomass at both sites was 1 214+46 kg ha-1 SEc. When postfire growing conditions were wet, current-year biomass of purple threeawn was reduced 90% and 73% with summer and fall fire, respectively. Under dry postfire growing conditions, purple threeawn current-year biomass was reduced 73% and 58% with summer and fall fire, respectively. Nitrogen additions had no effect on purple threeawn currentyear biomass at either site. Current-year biomass of C3 perennial grass doubled with nitrogen additions and was not impacted by fire during a wet spring. Nitrogen additions and fire had no effect on C3 perennial grass current-year biomass following a dry spring. Prescribed fire appears to be a highly effective tool for reducing purple threeawn abundance on semiarid rangelands, with limited detrimental impacts to nontarget species.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Implications of Invasion by Juniperus Virginiana on Small Mammals in the Southern Great Plains

Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examined effects of invasion by eastern red cedar on small mammals in 3 plant communities (tallgrass prairie, old field, and cross-timbers forest) in the cross-timbers ecoregion in Oklahoma. We sampled small mammals seasonally from May 2001 to August 2002 by using Sherman live traps and mark–recapture techniques on 3.24-ha, 450-trap grids in each plant community. We sampled vegetation in two hundred twenty-five 12 x 12-m cells within each grid. The structure of the small-mammal community differed among the 3 habitat types, with higher species diversity and richness in the tallgrass-prairie and old-field sites. Overall, the small-mammal community shifted along a gradient of increasing eastern red cedar. In the old-field and tallgrass-prairie plots, occurrence of grassland mammals decreased with increasing red cedar, whereas only 1 woodland mammal species increased. In the cross-timbers forest site, percent woody cover (height), rather than cover of red cedar, was the most important factor affecting woodland mammal species. Examination of our data suggests that an increase in overstory cover from 0% to 30% red cedar can change a species-rich prairie community to a depauperate community dominated by 1 species, Peromyscus leucopus. Losses in species diversity and changes in mammal distribution paralleled those seen in avian communities invaded by eastern red cedar. Our results highlight ecological effects of invasion by eastern red cedar on diversity and function at multiple trophic levels