Invasive Species
View article.
This study tested the stress-gradient hypothesis (SGH) in observations of 75 sites along overlapping water and heat stress and disturbance gradients. As stress-disturbance levels increase, sagebrush-herbaceous plant facilitation levels increase, the landscape will become increasingly aggregated as a product of necessary facilitation between sagebrush and herbaceous plants. This aggregation decreases the individual resilience of the native herbaceous plants, increases the competition from invasive plants, and decreases the overall stability and resilience of the sagebrush steppe ecosystem.
View abstracts.
These abstracts of recent papers on rangeland management in the West were prepared by Charlie Clements, Rangeland Scientist, USDA Agricultural Research Service, Reno, NV.
View article.
This study found that early seral natives generally outperformed late seral natives when growing with exotics and had earlier emergence timing, although results differed among functional groups and soil types. Survival probabilities, however, did not differ between the early and late seral mixes when growing without exotics. Within each seed mix, native grasses exhibited the highest emergence probabilities of the functional groups. Natives did not suppress exotics in early life stages. Performance of B. tectorum was higher on sandy loam, while T. caput-medusae was highly successful in both soil types. Performance of native functional groups differed by soil type when growing with exotics but did not differ when growing without exotics. Survival of native grasses, in particular, was generally higher on sandy loam when growing with exotics.
View report.
This final report includes actions to be implemented by Interior’s bureaus to immediately address the threat of rangeland fire and other disturbances to Western sagebrush-steppe landscapes and improve fire and fuels management efforts.
View abstracts.
These abstracts of recent papers on range management in the West were prepared by Charlie Clements, Rangeland Scientist, USDA Agricultural Research Service, Reno, NV.
View article.
In this news article, work by Ann Kennedy, scientist at Washington State, Susan Meyer, USFS research ecologist, and others is highlighted. Their work includes sorting through some 20,000 strains of naturally occurring soil bacteria to discover two that single out cheatgrass.
View report.
This report provides a strategic approach for conservation of sagebrush ecosystems and greater sage-grouse that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on (1) factors that influence sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2) distribution, relative abundance, and persistence of sage-grouse populations to develop management strategies at both landscape and site scales.
View research brief.
This research brief highlights a study investigating whether on not deer mice could help combat the invasive weeds infiltrating desert landscapes after fire.
View synthesis.
This synthesis describes what is known about the cumulative impacts of historic livestock grazing patterns and short-term effects of livestock grazing on fuels and fire in sagebrush ecosystems. Over years and decades grazing can alter fuel characteristics of ecosystems. On a yearly basis, grazing can reduce the amount and alter the continuity of fine fuels, potentially changing wildlife fire spread and intensity. However, how grazing-induced fuel alterations affect wildland fire depends on weather conditions and plant community characteristics. As weather conditions become extreme, the influence of grazing on fire behavior is limited, especially in communities dominated by woody plants.
View synthesis.
This review of the literature found that in general long-term rest and modern properly managed grazing produce few significant differences. However, some topic areas have not been adequately studied to accurately predict the influence of long-term rest compared to managed grazing. In some situations, not grazing can cause an accumulation of fine fuels that increase fire risk and severity and, subsequently, the probability of sagebrush steppe rangelands converting to exotic annual grasslands. Shifts in plant communities (i.e., exotic annual grass invasion and western juniper encroachment), caused in part from historical improper grazing, cannot be reversed by long-term rest.