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LITTER REDUCTION BY PRESCRIBED BURNINGCAN EXTEND DOWNY BROME CONTROL Downy brome (Bromus tectorum L.) is a highly successful invasive species primarily because it fills an open niche in native plant communities. It also produces large amounts of litter over time. We hypothesized that removing accumulated litter with a prescribed burn before applying herbicides would improve herbicide efficacy, extending the duration of control. In January 2012, two downy brome infested sites were burned. In March 2012, post-emergent applications of glyphosate, imazapic, and tebuthiuron were made in a split-plot design.Aboveground biomass was collected at 6, 18 and 27 months after treatment (MAT) to evaluate treatment effects. In non-burned areas, all herbicide treatments were similar to the control 27 MAT; however, burning combined with imazapic or tebuthiuron reduced downy brome biomass 27 MAT by 81% ± 4.6 SE and 84% ± 19.3 SE, respectively. Remnant species responded positively to burning and herbicide treatments. Native cool season grass biomass increased after burning while native warm season grass biomass increased following tebuthiuron treatments.The impact of litter on imazapic and tebuthiuron availability was also evaluated. Herbicide interception increased in a linear relationship with increasing litter. For every 50 g·m -2 increase in litter there was a 7% increase in the amount of herbicide intercepted, meaning that 75% of the applied herbicide was intercepted by 360 g·m -2 of litter. A simulated rainfall event of 5 mm, 7 days after application, removed a significant amount of herbicide. This indicates that at sites with surface litter, timely precipitation could be critical for herbicide efficacy; however, when burning was used to remove litter and was followed by herbicides with residual soil activity, iii downy brome control was extended. Due to downy brome's relatively short seed viability in the soil, extending herbicide efficacy to several years could help to reduce the soil seed bank.iv ACKNOWLEDGEMENTS

This Report provides a strategic approach for conservation of sagebrush ecosystems and Greater SageGrouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) 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. A sage-grouse habitat matrix links relative resilience and resistance of sagebrush ecosystems with sage-grouse habitat requirements for landscape cover of sagebrush to help decision makers assess risks and determine appropriate management strategies at landscape scales. Focal areas for management are assessed by overlaying matrix components with sage-grouse Priority Areas for Conservation (PACs), breeding bird densities, and specific habitat threats. Decision tools are discussed for determining the suitability of focal areas for treatment and the most appropriate management treatments.

By killing cattle and otherwise complicating management, the many species of larkspur (Delphinium spp.) present a serious, intractable, and complex challenge to livestock grazing management in the western United States. Among the many obstacles to improving our understanding of cattle-larkspur dynamics has been the difficulty of testing different grazing management strategies in the field, as the risk of dead animals is too great. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management, and allow for realistic bottom-up encoding of cattle behavior. Here, we introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of Geyer’s larkspur (D. geyeri). This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in lethal acute toxicosis. As the first ABM to model grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity.

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Increasing fire frequencies and uncharacteristic severe fires have created a need for improved restoration methods across rangelands in western North America. Traditional restoration seed mixtures of native perennial mid- to late-seral plant species may not be suitable for intensely burned sites that have been returned to an early-seral condition. Under such conditions, native annual plant species are likely to be more successful at becoming established and competing with exotic annual plant species, such as Bromus tectorum L., for resources. We used a field study in Colorado and Idaho, USA, to test the hypothesis that native annual plant species are better suited to post-fire restoration efforts compared with perennial plant species that are commonly used in traditional seed mixtures. Replicated test plots at three post-fire sites were assigned one of four treatments: (1) native annual seed mixture, (2) standard perennial seed mixture, (3) combination of annual and perennial and (4) an unseeded control. Seeding native annuals with perennials resulted in a slight reduction in exotic plant cover, suggesting that it is potentially beneficial to include native annual plant species in restoration seed mixtures.

Cities are increasingly turning to food policy plans to support goals related to food access, food security, the environment, and economic development. This paper investigates ways that rural farmers, communities, and economies can both support and be supported by metropolitan food-focused initiatives. Specifically, our research question asked what opportunities and barriers exist to developing food policies that support urban food goals, particularly related to local procurement, as well as rural economic development. To address this question, we described and analyzed a meeting of urban stakeholders and larger-scale rural producers related to Colorado’s Denver Food Vision and Plan. We documented and explored “findings” gleaned from a supply chain diagraming and data compilation process that were then used to inform an event that brought together diverse supply chain partners. Three findings stand out. First, facilitating dialog between urban food policymakers and rural producers to understand potential tensions, mitigate such tensions, and capitalize on opportunities is essential. Second, perceptions and expectations surrounding “good food” are nuanced—a timely finding given the number of preferred procurement programs emerging across the county. Third, critical evaluation is needed across a diverse set of value chain strategies (e.g., conventional and alternative distribution) if food policy intends to support heterogeneous producers, their communities, and urban food policy goals.