Grazing lands support the livelihoods of millions of people across nearly one-half of the globe. Soils are the backbone of stability and resilience in these systems. To determine livestock grazing impacts on soil health, we conducted a global meta-analysis of soil organic carbon (SOC), total N, C/N ratio, and bulk density responses to grazing strategies (continuous, rotational, and no grazing) and intensities (heavy, moderate, and light grazing) from 64 studies around the world. Across all studies and grazing intensities, continuous grazing significantly reduced SOC, C/N, and total N compared with no grazing. Soil compaction (i.e., increased bulk density) was greater under both continuous and rotational grazing compared with no grazing; however, rotational grazing had lower bulk density than continuous grazing. Rotational grazing had greater SOC than continuous grazing and was not different from no grazing. The positive responses of SOC to rotational grazing could create climate change mitigation opportunities. Grazing strategy comparisons were minimally conditioned by aridity class (i.e., arid, subhumid, and humid); however, complete observations were notably limited or missing for many rotational grazing comparisons. For continuous and no grazing strategy comparisons, we found that grazing management can significantly influence soil function and health outcomes; however, site-specific environmental factors play important moderating roles. Greater coordination across regional, national, and global efforts, as well as consistent guidelines for soil health evaluation, would help overcome these knowledge gaps and vastly improve our collective understanding of grazing impacts on soil health, providing greater management and policy impacts.

World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus) grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus). However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July–mid September) grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this working landscape.

Policy makers and practitioners are in need of useful tools and models for assessing ecosystem service outcomes and the potential risks and opportunities of ecosystem management options. We utilize a state-and-transition model framework integrating dynamic soil and vegetation properties to examine multiple ecosystem services—specifically agricultural production, biodiversity and habitat, and soil health—across human created vegetation states in a managed oak woodland landscape in a Mediterranean climate. We found clear tradeoffs and synergies in management outcomes. Grassland states maximized agricultural productivity at a loss of soil health, biodiversity, and other ecosystem services. Synergies existed among multiple ecosystem services in savanna and woodland states with significantly larger nutrient pools, more diversity and native plant richness, and less invasive species. This integrative approach can be adapted to a diversity of working landscapes to provide useful information for science-based ecosystem service valuations, conservation decision making, and management effectiveness assessments.

Exclusion of cattle by fencing has been proposed to alleviate possible negative grazing impacts on hydrologic, water quality, and cover habitat conditions within Sierra Nevada meadows used by Yosemite toads (Bufo canorus Camp) for breeding. Our objectives were to: 1) determine associations between breeding pool habitat conditions and use of potential breeding pools by toads; and 2) determine how habitat conditions respond to cattle exclusion treatments on the Sierra National Forest, California. We randomly selected two toad occupied and two unoccupied breeding pools in each of nine meadows for this study (n 5 36 breeding pools). After baseline data collection in 2006, three meadow fencing treatments were implemented over the course of 3 yr. Treatments were fencing to exclude cattle from the entire meadow; fencing to exclude cattle from toad breeding and rearing areas, with grazing allowed in the remaining unfenced portion of the meadow; and cattle grazing allowed across entire meadow. We monitored hydrologic, water quality, and cover habitat variables as well as toad occupancy during the breeding seasons of 2006 through 2008. Concentrations of water quality constituents were uniformly low all years regardless of treatment. Occupied pools were shallower, warmer, and more nitrogen enriched than unoccupied breeding pools. We found no evidence of improved toad breeding pool habitat conditions following fencing compared to standard US Forest Service grazing management. Resumen La exclusión del ganado por medio de cercos ha sido propuesto para reducir los posibles impactos negativos del pastoreo en la calidad del agua, la hidrología y las condiciones de cobertura del hábitat dentro de las praderas de Sierra Nevada, usados por el sapo yosemite (Bufo canorus Camp) en su reproducción. Nuestros objetivos fueron: 1) Determinar las asociaciones entre las condiciones del hábitat en un estanque de cría y el uso de estanques potenciales de cría por sapos y 2) Determinar cómo las condiciones del hábitat responden a los tratamientos de exclusión del ganado en el bosque Nacional la Sierra en California. Seleccionamos al azar dos estanques de crianza de sapos ocupados y dos sin ocupar en cada una de las nueve praderas para este estudio (n 5 36 estanques de cría). Despue´s de los valores de referencia recabados en el 2006, se implantaron tres tratamientos de cercos en praderas por un periodo de tres añ os. Los tratamientos fueron, cercar para apartar el ganado de toda la pradera, cercar para excluir el ganado de la cría del sapo y su área de reproducción, permitiendo el pastoreo en la porción restante de la pradera sin cercar y permitir el pastoreo del ganado en toda la pradera. Se monitoreo la hidrología, calidad del agua y las variables de la cobertura del hábitat, así como la ocupación del sapo durante las temporadas de reproducción del 2006 al 2008. Monitoreamos las variables de hidrología, calidad de agua y la cobertura del hábitat así como la ocupación de los sapos durante las temporadas de reproducción del 2006 al 2008. Las c...

Ranchers are increasingly expected to manage grasslands for forage production and native biodiversity enhancement goals. However, longstanding relationships between grazing and plant species are often understudied because elucidating effects of grazing absence and presence often requires experimental opportunities that are difficult to establish, such as the introduction of grazing to long-term ungrazed pastures. Addressing this knowledge gap is critical for heterogeneous landscapes where site-specific properties might interact with grazing effects to ultimately structure plant communities. We conducted vegetation surveys for 3 years after grazing was reintroduced to an annual California grassland that was not grazed for more than 60 years. We investigated how grazing affected plant communities in terms of cover and richness of native and invasive species and how topographic sites of summit, backslope and toeslope altered these relationships. The plant communities were affected by the independent effects of grazing, site and year. Across years, native cover was 39% greater in grazed plots compared with ungrazed plots. Native species richness was slightly lower in ungrazed compared with grazed plots for toeslope sites relative to the other topographic positions. Invasive species cover was 17% lower in grazed plots compared with ungrazed plots and no predictors were found to contribute to significant differences across plots. Although we generally did not find expected relationships between site and plant response to grazing, this work demonstrates how managers can use livestock to quickly modify plant communities in areas with a long history of grazing absence.

Abstract. Montane meadows provide multiple ecological and economic benefits, and are widely considered areas of high conservation value. There is growing interest in balancing multiple land-uses on these and other focal working landscapes to provide for economic, social, and conservation goals. Globally, livestock grazing has been used as a management and conservation tool in many ecosystems; however, there is substantial concern-particularly for montane meadows-that grazing negatively impacts ecosystem functions and services. The mechanisms by which excessive livestock grazing can degrade meadow function have been well documented; yet, for hydrologically functional meadow systems, we know little about meadow-scale linkages in the hydrologic-soil-plant-grazing animal continuum, which limits our ability to develop riparian grazing conservation strategies. We conducted a cross-sectional, observational survey of hydrology, soils, plant communities, and cattle forage resource use across 24 functional montane meadows of the central Sierra Nevada Mountain Range in California, USA. By linking principles of plant community ecology and foraging theory, we were able to unravel relationships and drivers between hydropedologic conditions, plant community characteristics, and cattle grazing patterns. Our work demonstrates that hydrology is a critical driving factor of cattle foraging response, plant community attributes, and soil properties across these wetland ecosystems. Results indicate that these systems are resilient to the observed gradient of grazing disturbances. This information advances our understanding of how meadow-scale heterogeneity can be utilized in managing for multiple, and potentially conflicting, ecosystem services across working landscapes-particularly in the face of projected future climate changes and continually limited resources to support conservation and restoration projects.

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Contamination of surface waters with microbial pollutants from fecal sources is a significant human health issue. Identification of relative fecal inputs from the mosaic of potential sources common in rural watersheds is essential to effectively develop and deploy mitigation strategies. We conducted a cross-sectional longitudinal survey of fecal indicator bacteria (FIB) concentrations associated with extensive livestock grazing, recreation, and rural residences in three rural, mountainous watersheds in California, USA during critical summer flow conditions. Overall, we found that 86% to 87% of 77 stream sample sites across the study area were below contemporary Escherichia coli-based microbial water quality standards. FIB concentrations were lowest at recreation sites, followed closely by extensive livestock grazing sites. Elevated concentrations and exceedance of water quality standards were highest at sites associated with rural residences, and at intermittently flowing stream sites. Compared to national and state recommended E. coli-based water quality standards, antiquated rural regional policies based on fecal coliform concentrations overestimated potential fecal contamination by as much as four orders of magnitude in this landscape, hindering the identification of the most likely fecal sources and thus the efficient targeting of mitigation practices to address them.