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The science underpinning targeted grazing has been advancing for decades, supporting a major paradigm shift concerning the role of grazing in addressing critical natural resource management challenges across the globe. A next step for expanding adoption is to understand how conservation benefits derived from this practice may change depending on how the components of a targeted grazing strategy change. Using two studies on California annual rangeland, one with heifers and one with ewes, we evaluated how two stocking attributes that underpin a targeted grazing plan, animal density and grazing duration, influence the ability of livestock to reduce the abundance of the invasive annual grass medusahead (Taeniatherum caput-medusae [L.] Nevski) and increase the abundance of native plants. Across studies, conservation benefits tended to be higher (lower invasive plant abundance and greater native plant abundance) under higher stocking density and shorter stocking duration, but we also found evidence that stocking density could be relaxed in some situations, allowing some conservation benefits to be achieved by grazing fewer animals over a longer duration. For California annual rangelands where most vegetation growth occurs over a period of a few short weeks, the potential to achieve similar conservation benefits by extending grazing duration and using fewer animals represents a major opportunity to apply targeted grazing over larger areas in one season with a set number of grazing animals. These initial findings provide justification for more extensive research in how changes in targeted grazing strategies may alter conservation benefits from grazing. Such insight is essential for understanding the range of cost-benefit trade-offs that may occur with this practice.

The invasive annual grass medusahead (Taeniatherum caput-medusae [L.] Nevski) poses a substantial threat to the health and function of rangelands across the western United States. On rangelands containing other desirable annual grasses, selective control of medusahead is difficult as this invasive species has traits similar to those of desired species. One key trait that differs between medusahead and other annual grasses is the rate and timing of phenological development. In this study we define management states for medusahead on the basis of the patterns of variation of forage palatability and susceptibility of seed production to defoliation over phenological stages. We integrate these management states with field observations to model the rates and timing of phenology-based management states to identify when targeted grazing or mowing treatments are most appropriate using Dirichlet regression and multistate modeling. While defoliation at any phenological stage from V3 (boot) to R8 (milk stage...

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.

Exposure of livestock grazing to forage productivity variation and to market fluctuations affects the risk of investment and returns from cow-calf operations, but little work has been done to empirically compare these returns to the returns that would be demanded by financial markets from assets with similar risk and return characteristics. This study uses historical forage production data from three rangeland locations in California, and cattle and hay prices, to simulate financial statements for three hypothetical cow-calf producers in the period 1988–2007. Return on investment from year to year incorporates the variability and risk associated with dependence on natural forage production. Performance is then compared to the actual performance of a diversified portfolio of assets using the Capital Asset Pricing Model, from which the theoretical cost of capital for these hypothetical grazing enterprises is derived. Much like other agricultural enterprises, cow-calf production in California has low market risk and a low theoretical cost of capital. This theoretical cost of capital is still greater than the historical return from livestock production (excluding land appreciation) in the western United States, adding further backing to the point often made in the literature that ranchers who engage in cow-calf production are receiving benefits beyond the commercial returns from livestock production alone.

Author(s): Brownsey, Philip; Davy, Josh; Becchetti, Theresa; Easley, Maddison L; James, Jeremey J; Laca, Emilio A | Abstract: Barb goatgrass and medusahead are invasive annual grasses that have spread or have the potential to spread throughout much of California's annual grasslands. Barb goatgrass is a B-rated noxious weed and medusahead is a C-rated noxious weed in the State of California, meaning that they both cause economic or environmental detriment. Both are prolific seed producers, making management to reduce their abundance possible but eradication difficult and unlikely. This publication gives a thorough description of growth stages of these invasive plants so you can employ the optimum timing of grazing and mowing treatments for management in your situation. Includes color photographs of key growth stages.