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. © Published by Elsevier Inc. On behalf of Society for Range Management.

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. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.

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. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.

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. © Published by Elsevier Inc. On behalf of Society for Range Management.