Western rangelands are currently under severe threat from exotic annual grasses. To successfully manage rangelands that are either infested with or susceptible to exotic annual grasses, we must focus on increasing resilience to disturbance and resistance to exotic annual grass invasion. Here, we present a fuel-based model and research framework for Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle & Young) rangelands that focuses on increasing resilience to fire and resistance to exotic annual grasses through the maintenance of perennial bunchgrasses. By maintaining perennial bunchgrass, exotic annual grasses have limited resources, thus decreasing the invasibility of the site. In order for the fuel-based model to be effective in guiding land management practices, research that evaluates the interactions between biotic and abiotic factors that influence fire-induced bunchgrass mortality is needed. Hence, we propose a research framework to identify and fill potential gaps in current scientific knowledge. We also suggest potential research objectives that are necessary to make informed management decisions before wildfire, with a goal to ultimately decreasing our reliance on marginally successful postfire restoration practices through preemptive management strategies.

Fertilization can affect vegetation dynamics and natural grassland diversity. This study evaluated the vegetation dynamics of a natural grassland 16 years after the initial fertilization, discussing the long-term effects of addition of triple superphosphate (TP) or Gafsa rock phosphate (RP) sources, as well as the effect of exotic species introduction on the inter seasonal dynamic of floristic composition. Phosphate (P) was applied in 1997, 1998, 2002, 2010, and 2012 at the quantities of 78.6, 39.3, 43.7, 43.7 and 43.7 kg·ha^-1, respectively, totaling 249 kg·ha^-1 P. Total herbage mass production (THM) with RP (13 485 kg·ha^-1) and TP applications (14 668 kg·ha^-1) was higher than in the Control (11 291 kg·ha^-1). There was a higher warm tussock perennial grasses C₄ contribution on herbage mass (HM) during the summer season (1 106 kg·ha^-1), whereas it was similar between treatments. In summer, the warm-season prostrate perennial grasses C₄ group contribution for HM was on average 48% higher when RP was used (1 590 kg·ha^-1) in relation to the other treatments. The HM contribution from the cool season annual grasses C₃ group (CAG) in the total HM, over spring 2012, winter and spring 2013 in TP treatment, was 17% higher than the other treatments. The changes in the seasonal botanical composition dynamics mainly by inducing modifications in the proportion of Paspalum notatum A. H. Liogier ex Flüggé on RP treatment and Paspalum urvillei Steud. and Lolium multiflorum Lam. on TP treatment. However, no significant effects were observed in species richness, which ranged from 19–24 species among growth seasons. In the same way, the Shannon Diversity Index and Pielou Equitability Index were not modified by historical P sources. These results indicate that phosphorus fertilization has lower effects on natural grasslands diversity and could be used as a tool with important implications for livestock.

The Gunnison sage-grouse (GUSG) is an iconic species recently proposed for protection under the Endangered Species Act (ESA). In Colorado's Upper Gunnison River Basin, ranchers own the majority of water rights and productive river bottoms as well as approximately 30% of the most important GUSG habitat. This project used mixed-methods interviews with 41 ranch owners to document how ranchers perceive the proposed ESA listing and how they plan to respond to a listing decision. Results show that ranchers support on-the-ground GUSG conservation but are concerned about listing implications. Ranchers are most concerned about their ability to manage public and private lands productively and continue permitted grazing on public lands. If the species is listed, landowners plan to decrease participation in conservation strategies, including plans to adopt conservation easements, participation in conservation programs, and willingness to allow access to private lands for GUSG monitoring. Land-owners also express plans for increased sales of land and water, which could have negative consequences for GUSG habitat. This research suggests that changes in the application of the ESA could lead to beneficial conservation outcomes. These changes include increased transparency, ability to exclude stable populations from listing under the ESA, and commitment to work with local bodies if the species is listed. This project demonstrates the importance of qualitative research for understanding the indirect and unintended effects of species protections in an increasingly interconnected world.

Elephant-induced thicket degradation in the Addo Elephant National Park (AENP), Eastern Cape, South Africa, was assessed during 1973 and 2010 using multitemporal satellite imagery. Changes in the thicket condition, in relation to the AENP expansion, were analyzed using the Normalized Difference Vegetation Index, postclassification, and landscape metrics. The change detection of land-cover classes was analyzed by postclassification. Landscape-spatial metrics were used in order to gain an understanding of vegetation-fragmentation trends. Temporal changes in vegetation gradients in relation to water points and thicket conditions within the botanical reserves were also assessed. The thicket condition was noted to have deteriorated, as the AENP had expanded. An expansion of degraded vegetation away from the water points was identified during the study period. The thicket condition in botanical reserve 1 had fluctuated, whereas it remained constant in reserves 2 and 3. Landscape spatial-metric analyses revealed evidence of increased vegetation fragmentation, as new areas of the AENP had been opened for elephant activity. A progressive decline in intact thicket and an increase in degraded thicket were observed. Remote-sensing techniques can assist with thicket-clump restoration by applying “target monitoring” for the timeous identification of potential-degradation hotspots.

Most remaining grasslands are used for livestock grazing; stocking rates could be managed to help stop declining songbird populations. We examined the effects of stocking rates on grassland songbirds in northern mixed-grass prairies using a beyond—Before-After-Control-Impact manipulative experiment in Canada's Grasslands National Park and adjacent community pastures. The study area consisted of nine 300-ha pastures grazed at a range of stocking rates starting in 2008. We conducted songbird surveys at six upland plots in each pasture from 2006–2010 and measured vegetation structure within each plot from 2008–2010 (n = 54). We evaluated the effects of stocking rates on habitat structure and songbird abundance using linear and generalized linear mixed models. Baird's sparrow (Ammodramus bairdii) relative abundance declined with increasing stocking rates. Chestnut-collared longspur (Calcarius ornatus) relative abundance increased only at higher stocking rates, indicating a possible threshold effect. Savannah sparrow (Passerculus sandwichensis) relative abundance decreased with stocking rates above 0.4 AUM after a year of grazing. Sprague's pipit (Anthus spragueii) relative abundance declined with grazing, but the effect was weak and only significant in 1 year. Western meadowlark (Sturnella neglecta) abundance was unaffected by grazing. Stocking rates may be used to benefit grassland songbirds and may alter avian communities after as little as 1 month of livestock grazing. Applying a range of stocking rates regionally may provide habitat for many species.

Supplementing wildlife populations with resources during times of limitation has been suggested for many species. The focus of our study was to determine responses of northern bobwhite (Colinus virginianus; Linnaeus) and scaled quail (Callipepla squamata; Vigors) to artificial surface-water sources in semiarid rangelands. From 2012–2014, we monitored quail populations via radio telemetry at Beaver River Wildlife Management Area, Beaver County, Oklahoma. We used cumulative distribution functions and resource utilization functions (RUFs) to determine behavioral responses of quail to water sources. We also used Program MARK to determine if water sources had any effect on quail vital rates. Our results indicated that both northern bobwhite and scaled quail exhibited behavioral responses to the presence of surface-water sources. Northern bobwhite selected for areas < 700 m and < 650 m from water sources during the breeding and nonbreeding season, respectively. However, the nonbreeding season response was weak ( = -0.06, SE = < 0.01), and the breeding season ( = 0.01, SE = 0.02) response was nonsignificant on the basis of RUFs. Scaled quail selected for areas < 650 m and < 250 m from water sources during the breeding and nonbreeding season, respectively. The breeding season RUF ( = -0.31, SE = 0.07) indicated a stronger response for scaled quail than bobwhite. Conversely, there was no direct effect of surface water on quail vital rates or nest success during the course of our study. Although water may affect behavioral patterns of quail, we found no evidence that it affects quail survival or nest success for these two species.

Grazing tolerance of dominant native species may determine the fate of rangeland ecosystems, and using native plant populations with good grazing tolerance in restoration seedings may improve ecosystem resilience, especially when domestic herbivores are present. We examined interspecific and intraspecific differences in shoot biomass and defoliation tolerance for two semiarid, perennial cool-season bunchgrasses native to the Intermountain West, USA, Pseudoroegneria spicata and Elymus wawawaiensis, on the basis of four functional traits (specific leaf area [SLA], plant basal area, tiller number, and tiller mass). We applied two treatments, control and boot-defoliation, where the latter included defoliation at the early-reproductive (“boot”) stage, the phenological stage most vulnerable to herbivory, while the control treatment did not. We tested two contrasting hypotheses (i.e., that boot-defoliation tolerance is increased through either increases in SLA or through more favorable tiller demography). For shoot biomass, both grasses were less productive under the boot-defoliation treatment than for the control, but E. wawawaiensis displayed higher boot-defoliation tolerance than P. spicata. Interpopulation variation occurred in all four functional traits for P. spicata, but there were no such variation for E. wawawaiensis. The tiller demography hypothesis better explained boot-defoliation tolerance in both species, and neither SLA nor plant basal area was correlated with shoot biomass for either treatment. Of the traits measured, high tiller number served as the primary mechanism for shoot biomass and boot-defoliation tolerance in P. spicata, while tiller number and tiller mass were both important predictors of both shoot biomass and boot-defoliation tolerance.

Sagebrush (Artemisia tridentata Nutt.) plant communities in the Great Basin region are being severely impacted by increasingly frequent wildfires in association with the expansion of exotic annual grasses. Maintaining native perennial bunchgrasses is key to controlling annual grass expansion, but postfire restoration of these species has proven difficult with traditional fall drill-seeding. We investigated the potential for winter/spring seeding bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Love) in southeast Oregon. In 2011–2013, 500 seeds were planted in fall, or weekly from March through early May in 1·m^-2 plots using a randomized block design with 5 replications. Germination was estimated using buried bags, and emergent seedlings were counted weekly from March to June. Germination and emergence varied strongly between years and by within-year timing of planting. With adequate precipitation, percent germination was high (up to 100%) regardless of timing of planting and emergence density decreased (P ≤ 0.05) with advancing winter/spring planting date in drier years. Emergence density was high (approaching 300 plants/m^-2) with adequate precipitation but varied strongly across planting weeks for winter/spring plantings. Percent survival of emergent seedlings to harvest (July) was approximately 25–50% lower (P ≤ 0.05) for fall-planted seeds in all years; survival of winter/spring seedlings was 80–100% with no discernable pattern between planting weeks. Our results indicate that winter/spring seeding of perennial bunchgrasses is biologically feasible in years with adequate precipitation but fall seeding was more consistently successful. Additional research is needed to determine environmental factors driving within-year variation in demographics for winter/spring planted seeds.

Few seed sources of North American forbs are available for revegetation/restoration of degraded western rangelands adapted to annual precipitation zones less than 300 mm, and those that are available are mainly wildland collected. The amount of time and resources necessary to make wildland collections in quantity results in high seed prices and variable seed quality, such that forbs have been under-represented in rangeland seeding mixes. We have previously identified western prairie clover (Dalea ornata Douglas ex Hook.), Searls' prairie clover (Dalea searlsiae A. Gray), and basalt milkvetch (Astragalus filipes Torr. ex A. Gray) as native species adapted to low precipitation zones in the western United States for which field-grown seed production would potentially reduce seed costs and increase availability. A series of glasshouse experiments were conducted to determine the effects of scarification, planting depth, and soil composition on germination and seedling emergence of these species. All three species produce hard seeds, and scarification was necessary to increase germination and seedling emergence. Compared with a 6-mm planting depth, a planting depth of 19 mm retarded the rate of emergence for all species but only reduced the total seedling emergence for basalt milkvetch. With seed scarification in sandy soils, prairie clover seedling emergence exceeded 80% while basalt milkvetch was less than 10%. With seed scarification in soils with higher clay content, prairie clover total seedling emergence reduced to 58–70% while basalt milkvetch increased to approximately 30%. Along with enhancing stand establishment in seed production fields, these data will assist land managers in planning for optimal establishment of these species in rangeland revegetation/restoration projects.

The authors regret that there was a mistake in the affiliation provided. The correct affiliation line should read “US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID 83706, USA”