Search USGS⌕ Search
Home/Archive/USGS

USGS · 70249968

Biocrusts indicators of livestock grazing effects on soil stability in sagebrush steppe: A case study from a long-term experiment in the northern Great Basin

Stella M. Copeland·Lea A. Condon·Roger Rosentreter·Jesse Miller·Maya Kahn-Abrams
View original source ↗Export metadata ↓

Abstract

Biocrusts are sensitive to changes in livestock grazing intensity in arid rangelands and may be useful indicators of ecosystem functions, particularly soil properties like soil stability, which may suggest the potential for soil erosion. We compared biocrust community composition and surface soil stability in a big sagebrush (Artemisia tridentata) steppe rangeland in the northwestern Great Basin in several paired sites, with or without long-term cattle grazing exclusion, and similar soils (mostly sandy loams), climate, and vegetation composition. We found that livestock grazing was associated with both lower surface soil stability and cover of several biocrust morphogroups, especially lichens, compared with sites with long-term livestock exclusion. Surface soil stability did not modify the effects of grazing on most biocrust components via interactive effects. Livestock grazing effects on total biocrust cover were partially mediated by changes in surface soil stability. Though lichens were more sensitive to grazing disturbance, our results suggest that moss (mostly Tortula ruralis in this site) might be a more readily observable indicator of grazing-related soil stability change in this area due to their relatively higher abundance compared with lichens (moss: mean, 8.5% cover, maximum, 96.1%, lichens: mean, 1.0% cover, maximum, 14.1%). These results highlight the potential for biocrust components as sensitive indicators of change in soil-related ecosystem functions in sagebrush steppe rangelands. However, further research is needed to identify relevant indicator groups across the wide range of biocrust community composition associated with site environmental characteristics, variable grazing systems, other rangeland health metrics, and other disturbance types such as wildfire.

Explore related subjects

Rangeland Ecology & ManagementArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Stella M. Copeland, Lea A. Condon, Roger Rosentreter, Jesse Miller, Maya Kahn-Abrams. 2023. Biocrusts indicators of livestock grazing effects on soil stability in sagebrush steppe: A case study from a long-term experiment in the northern Great Basin. https://doi.org/10.1016/j.rama.2023.09.001

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Long-term effects of rangeland improvements on cattle distribution: A ranch-scale case study

Resource matching can be a common assumption that underlies anthropogenic rangeland improvements for wildlife or livestock. Countless resources are spent on targeted vegetation manipulations for both livestock and wildlife, but selection for improved areas has not been well quantified in livestock. This case study investigates whether cattle exhibit preferential use of historically improved rangeland sites within sagebrush steppe ecosystems, and whether these effects are relevant long-term compared with inherent landscape heterogeneity. We used a generalized linear mixed-effects resource selection function on Global Positioning System points collected at a fix rate of 2 h from a subset of animals grazing throughout 14 pastures (totaling 13 079 ha) over 3 yr to investigate cattle distribution in relation to historical rangeland improvements. These consisted of various methods for reducing woody plant cover and increasing forage production, most followed by grass and legume reseeding. Overall selection for treated areas was positive (0.16, P < 0.0 0 01), but highly variable (pasture estimates range from-1.81 to 0.77). Differences in enhanced vegetation index (EVI) accounted for 25% of the variation in treatment selection, whereas herbaceous production did not have an appreciable effect on treatment selection. Within individual pastures, the effects of landscape variables (distance to water, slope, herbaceous production, EVI, tree cover, and shrub cover) were more variable than treatment effects and on average 2.4-fold more influential to selection than anthropogenic treatments. Still, the combined effects of all landscape variables accounted for only 8% of the variation in site selection. The observed inconsistency among selection patterns underscores the complexity of large herbivore resource selection behavior, and the statistical challenges to modeling that behavior. These results provide limited and inconsistent support for the hypothesis that large herbivores select long-term (5–20 yr post establishment) for range improvements in relation to their forage quality/quantity in a resource-matching manner.

Utah↗
USGS2026

Habitat restoration efforts increase patch retention times in migratory mule deer (Odocoileus hemionus)

Mule deer ( Odocoileus hemionus ) populations have been declining across much of their range, often due to habitat alteration. Habitat alterations, including the introduction of non-native annual grasses and the expansion of pinyon–juniper (PJ) forests on sagebrush ecosystems, are changing resource availability compared to historical conditions. Extensive habitat restoration has been completed across the State of Utah to foster plant communities that better reflect historical conditions and optimal mule deer habitat. We investigated how patch retention times differ on eight different habitat restoration treatment types and random locations during summer and winter across the State of Utah, to evaluate the efficacy of restoration treatments for migratory mule deer, as retention time is expected to reflect resource availability. We developed seasonal moving-window Brownian Bridge Movement Models for individual mule deer ( n = 593 animals), and intersected occurrence distributions (OD) with habitat restoration treatments and randomly generated background landscape polygons. We quantified patch retention time as the number of days individuals’ OD overlapped treatment or random polygons during each season, using a Poisson regression. In winter sites treated to remove PJ, both with (56.5 days, 95% CI [29.3, 108.0]) and without seeding (55.3 days, 95% CI [29.1, 105.8]), as well as sagebrush restoration sites (59.0 days, 95% CI [30.6, 114.8]), had increased retention times when compared to the landscape average (41.9 days, 95% CI [20.7, 84.1]), with effects decreasing 5+ years post-treatment. Retention times in summer were longer across all treatment types in the 2–4-year post-treatment age class (37.5 days, 95% CI [26.3, 53.1]) compared to the landscape average (28.6 days, 95% CI [25.7, 31.8]). Our results demonstrate the positive effects of habitat restoration through increased patch retention times on mule deer winter and summer range and may suggest follow-up treatment 5+ years after initial treatment to maximize mule deer use.

Utah↗
USGS2026

Dormant-season prescribed fires can enhance forage quality for two growing seasons in the northwestern Great Plains

Fire is an ecological disturbance that can accelerate nutrient cycling and alter herbivore distribution in grasslands and shrublands. Historically and today, humans have used prescribed fire to enhance forage quality for wild and domestic herbivores, and to achieve other management objectives. Contextual factors such as ecosystem type, seasonality, and fuel characteristics can determine how prescribed fire affects forage quality. For example, forage quality enhancements are relatively short lived in shortgrass steppe and subhumid grasslands but may persist for multiple years in northern mixed-grass prairie and sagebrush steppe. Outcomes near ecosystem boundaries are uncertain. Using 152 independent, small-plot, prescribed burns completed over multiple years at 36 sites in Wyoming and South Dakota, USA, we tested the effects of ecosystem type (northern mixed-grass prairie vs. sagebrush grassland ecotone), burn seasonality (fall vs. spring), and fuel characteristics (ambient vs. added fuel) on forage quality. Across ecosystems, fall fires had strong positive effects on forage quality parameters during the first growing season after fire, and energy benefits that persisted into the second growing season after fire. In northern mixed-grass prairie, spring and fall prescribed fires implemented before the same growing season yielded similar forage quality enhancements for one season. Finally, artificially increased fuel loads had few effects on forage quality. Although forage quality rarely dropped below critical nutrition thresholds for ruminants regardless of burning, our findings suggest relatively consistent, positive forage quality responses to prescribed fire across ecosystem types, seasonality of dormant-season burns, and fuel characteristics. Many improvements lasted through one growing season, and some persisted into a second growing season. Managers could take advantage of short-term nutritional benefits via adaptive management strategies that allow animals access to burned and unburned areas.

South Dakota, Wyoming↗