Rangelands, 50 % of the earth's land surface, produce a renewable resource of cellulose in plant biomass that is uniquely converted by ruminant livestock into animal protein for human consumption. Sustainably increasing global animal production for human consumption by 2050 is needed while reducing the environmental footprint of livestock production. To accomplish this, livestock producers can interseed legumes and use bioenergy protein byproducts for increased dietary protein, develop forage "hot spots" on the landscape, use adaptive grazing management in response to a changing climate, incorporate integrated livestock-crop production systems, improve fertility to increase birth rates, and reduce livestock losses due to disease and pest pressure. Conceptual advances in livestock production systems have expanded the utility of livestock in conservation-oriented approaches that include (1) efforts to "engineer ecosystems" by altering vegetation structure for increased habitat and species diversity, and structural heterogeneity; (2) use of targeted grazing to reduce invasive annual grasses and invasive weeds, and fuel reduction to decrease wildfires; and (3) improvement of the distribution of livestock grazing across the landscape. Livestock production systems need to increase output of animal protein by implementation of knowledge and technology, but this production must

A Stochastic Dynamic Programming (SDP) model is developed to analyze optimal stocking rates in the face of weather uncertainty and potential climate change projections. The model extends previous work modeling grazing as a predator‐prey relationship. Attention is given to profit maximizing decisions when growing season precipitation is unknown. Comparisons are made across results from a model that utilizes constant growing season precipitation in all years. Results suggest that optimal stocking rates and profitability decrease in climate change scenarios with increased precipitation variability as compared to the historical stochastic weather scenario.

ABSTRACT. Building models is an important way of integrating knowledge. Testing and updating models of social-ecological systems can inform management decisions and, ultimately, improve resilience. We report on the outcomes of a six-year, multidisciplinary model development process in the sagebrush steppe, USA. We focused on creating state-and-transition models (STMs), conceptual models of ecosystem change that represent nonlinear dynamics and are being adopted worldwide as tools for managing ecosystems. STM development occurred in four steps with four distinct sets of models: (1) local knowledge elicitation using semistructured interviews; (2) ecological data collection using an observational study; (3) model integration using participatory workshops; and (4) model simplification upon review of the literature by a multidisciplinary team. We found that different knowledge types are ultimately complementary. Many of the benefits of the STM-building process flowed from the knowledge integration steps, including improved communication, identification of uncertainties, and production of more broadly credible STMs that can be applied in diverse situations. The STM development process also generated hypotheses about sagebrush steppe dynamics that could be tested by future adaptive management and research. We conclude that multidisciplinary development of STMs has great potential for producing credible, useful tools for managing resilience of social-ecological systems. Based on this experience, we outline a streamlined, participatory STM development process that integrates multiple types of knowledge and incorporates adaptive management.

Grass‐legume mixtures are considered viable alternatives to nitrogen (N)‐fertilized grass pastures, but there is a dearth of information on effects of seed mass ratios on productivity and economic returns. We evaluated the effects of grass‐legume seed mass ratios and N fertilizer rates on forage accumulation, nutritive value, and profitability. There were 15 treatments arranged in randomized complete blocks with four replicates. The treatments included four species (meadow bromegrass [Bromus biebersteinii Roem. & Schult] and three legumes—alfalfa [Medicago sativa L.], sainfoin [Onobrychis viciifolia Scop.], and birdsfoot trefoil [Lotus corniculatus L.]), various seed mass ratios (100:0, 50:50, 70:30, 50:25:25, and 50:16.7:16.7:16.7), and three rates of N (0, 56, and 112 kg N ha−1) applied only to meadow bromegrass monocultures. The 2‐yr average annual forage accumulation of meadow bromegrass receiving 112 kg N ha−1 was 6.89 Mg ha−1 yr−1, which was similar to the 30% alfalfa + 70% meadow bromegrass, 30% birdsfoot trefoil + 70% meadow bromegrass, 25% alfalfa + 25% birdsfoot trefoil + 50% meadow bromegrass, and 50:16.7:16.7:16.7 mixture treatments. Mixtures had greater nutritive value than N‐fertilized meadow bromegrass. All treatments except 100% sainfoin and 50% sainfoin + 50% meadow bromegrass treatments were profitable. On the basis of forage accumulation, nutritive value, and profitability, the 30% alfalfa + 70% meadow bromegrass and 30% birdsfoot trefoil + 70% meadow bromegrass seed mass ratios are simple mixtures that may be viable alternatives to 100% alfalfa and N‐fertilized meadow bromegrass monocultures.

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