Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis Beetle & Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity. Revegetation of medusahead-invaded sagebrush plant communities is necessary to restore ecosystem services. Disagreement, however, exists over whether to seed native or introduced perennial species to revegetate communities after controlling medusahead. Though native species generally do not establish as well as introduced species, interference from co-seeded introduced species has often been attributed to the limited success of natives. The potential for seeding natives to revegetate communities after medusahead control is relatively unknown because they have been largely co-seeded with introduced species. We compared the results of seeding native and introduced perennial species after controlling medusahead with prescribed burning followed with an imazapic herbicide application at five sites. Perennial bunchgrass cover and density were 5- and 10-fold greater in areas seeded with introduced compared with native species 3 years post seeding. Furthermore, exotic annual grass cover and density were less in areas seeded with introduced compared with native species. Seeded introduced and native shrubs largely failed to establish. High perennial bunchgrass density (15 individuals · m-2) in areas seeded with introduced species in the third year post seeding suggests that the succession trajectory of these communities has shifted to becoming perennial dominated. Average perennial bunchgrass density of 1.5 individuals · m-2 with seeding native species will likely not limit medusahead and appears to already be converting back to exotic annual grass-dominated communities. These results suggest that seeding introduced compared with native species after medusahead control will likely be more successful. Our results also imply that if natives are selected to seed after medusahead control, additional resources may be necessary to recontrol medusahead and repeatedly sow native species. © 2015, Elsevier Inc. All rights reserved.

Invasive plant response to control efforts is strongly modified by site-specific factors, treatment timing, and environmental conditions following treatment, making management outcomes challenging to predict. Systematic reviews, which involve quantitative synthesis of data, can address this challenge by identifying general patterns of treatment effects across studies and quantifying the degree to which these effects vary. We conducted a systematic review of medusahead (Taeniatherum caput-medusae [L.] Nevski) control treatments that couples a meta-analysis on control data with an assessment of stakeholder needs to identify critical medusahead management knowledge gaps. With the meta-analysis we generated effect size estimates of how combinations of herbicide, burning, seeding, and grazing impacted medusahead on rangeland dominated by either annual or perennial vegetation. All combinations of treatments in both rangeland systems provided significant short-term control of medusahead, although treatment effects were highly transient on perennial rangeland, particularly for seeding treatments. Stakeholders listed grazing as a preferred management tool, and on annual rangeland an almost twofold reduction in medusahead abundance was achieved by timing high stocking rates to match phenological stages when medusahead was most susceptible to defoliation. Insufficient data were available to evaluate effects of grazing on medusahead on perennial rangeland. On the basis of these data and our stakeholder survey, four major information needs emerged, including the need to better understand 1) seedbank response to burning and herbicide treatments, 2) how to optimize grazing animal impacts on medusahead given ranch enterprise constraints, 3) costs and benefits of control and risk of practice failure, and 4) impacts of adaptive management treatments conducted on larger scales and at longer time intervals. Addressing these knowledge gaps should help overcome key ecological and economic barriers inhibiting implementation of medusahead and other invasive plant management programs on rangeland and provide a positive step toward conserving the critical ecosystem services these systems provide. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.

Two in vitro trials were conducted for estimates of dietary percentage of fourwing saltbush (Atriplex canescens; FS) or winterfat (Krascheninnikovia lanata; WF) for improved dietary digestibility when cattle graze mature cool-season grass. Three in vitro trials were conducted to estimate percentage of FS and WF seeds that could survive passage through the bovine gastro-intestinal tract (GIT) with potential for fecal seeding. Mixtures of FS and mature smooth bromegrass (Bromus inermis; SB) or WF and SB had greater apparent digestibility than SB alone (P < 0.0001). There were positive linear relationships (r2 ≥ 0.93) between the amount of each shrub in digested mixtures and digestibility. Similar relationships were observed with mixtures of FS and mature Altai wildrye (Leymus angustus). Germination of Dakota FS seeds in the first trial, incubated for 24 or 48 h, was 55% and 47%, respectively, with no difference in germination of seeds for the 24- and 48-h incubations (P = 0.26), but more seeds germinated if incubated versus not (P ≤ 0.002). Germination of Utah FS seeds, which were incubated for 24 or 48 h with high-, medium-, or low-quality forage, averaged 9% and 8%, respectively. Length of incubation, forage quality, and their interaction did not influence germination (P ≥ 0.45). Germination of nonincubated Utah FS seeds was 21% and greater than for incubated seeds (P = 0.004). Average germination of WF seeds was 0.6% and 0.1% for 24- and 48-h incubations, respectively, with incubation length, forage quality, and their interaction not significant (P ≥ 0.31). Nonincubated WF seeds had greater germination (42%) than incubated seeds (P < 0.0001). Results from the third trial were confirmatory for Dakota FS seed. FS and WF can improve diet quality of grazing cattle in late summer through winter, and some FS seeds have potential for fecal seeding. © 2015, Elsevier Inc. All rights reserved.

Rangeland carrying capacity depends on aboveground net primary production (ANPP) and on the sustainable harvest index (HIsust), the portion of ANPP that livestock can consume without undermining the production capacity of the system. At a regional scale, the observed harvest index (HIreal) increases with ANPP, but at a landscape scale the pattern is less clear, and controls of HIreal and HIsust are unknown. We analyzed the landscape patterns of variation of HIreal and HIsust across gradients of ANPP, pastoral value of vegetation (PV), and degradation. In 15 plots of a 2 753-ha paddock in a western Patagonian grass-shrub steppe, we estimated ANPP, consumption, forage pastoral value, and degradation. To estimate degradation we used PV weighed by forage cover because it was negatively correlated with a combination of ecosystem traits formerly linked to grazing-induced degradation. We calculated HIreal (consumption/ ANPP) and HIsust (consumption removing 40% of aerial biomass of the key species/ANPP). We choose Festuca pallescens as the key species because of its high abundance and moderate preference. As the paddock was grazed with low stocking rate to maximize among-plots selection, HIreal was lower than HIsust. As in regional models, HIsust and HIreal increased with ANPP within the paddock (R2 = 0.33 and 0.30, respectively). Multiple regressions showed that HIreal increased with ANPP and degradation, while HIsust increased with ANPP but decreased with degradation (R2 = 0.64 and 0.77, respectively). This suggests that at stocking rates lower than carrying capacity, sheep choose highly productive stands and, at a given level of ANPP, they prefer degraded stands. In contrast, carrying capacity increases with productivity and decreases with degradation. Management systems based on HIsust may result in severe biomass removal of species more preferred than the key species (Poa ligularis), and it is necessary to include strategies to preserve their individuals and populations. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.

Broadcast seeding is one of the most commonly applied rehabilitation treatments for the restoration of burned piñon and juniper woodlands, but the success rate of this treatment is notoriously low. In piñon-juniper woodlands, postfire soil-water repellency can impair seeding success by reducing soil-water content and increasing soil erosion. Implementing anchor chaining immediately after seeding can improve establishment of seeded species by enhancing seed-to-soil contact and may improve restoration success by decreasing soil-water repellency through soil tillage. The objectives of this research were to 1) determine if anchor chaining in postfire pinyon-juniper woodlands diminishes soil-water repellency, and 2) determine meaningful relationships between soil-water repellency, unsaturated hydraulic conductivity [K(h)], and the establishment of seeded and invasive species. Research was conducted on two study sites, each located on a burned piñon-juniper woodland that had severe water repellency and that was aerially seeded. At each location, plots were randomly located in similar ecological sites of chained and unchained areas. At one location, anchor chaining considerably improved soil hydrologic properties, reducing the severity and thickness of the water-repellent layer, and increasing soil K(h) 2- to 4-fold in the first 2 yr following treatment. At this same location, anchor chaining increased perennial grass cover 16-fold and inhibited annual grass and annual forb cover by 5- and 7-fold, respectively. Results from the second site only showed improvements in soil K(h); other hydrologic and vegetative treatment responses were not significantly improved. Overall, this research suggests that anchor chaining has the potential to improve restoration outcomes, though additional research is warranted for understanding the direct impact of anchor chaining on soil-water repellency without the interaction of a seeding treatment. © 2015, Elsevier Inc. All rights reserved.