Impacts of livestock grazing on the probability of burning in wildfires vary by region and vegetation type in California.

Wildfire activity has recently increased in California, impacting ecosystems and human well-being. California's rangelands are complex social-ecological systems composed of multiple ecosystems and the people who live and work in them. Livestock grazing has been proposed as a tool for reducing wildfire activity. Here, we explore how grazing affects wildfire at large spatial scales, assessing burn probability on rangelands with different grazing levels. We collected grazing data by surveying 140 large private landowners in three social-ecological regions: California's North Bay, Central Coast, and Central Valley and Foothills. Using pre-regression matching and mixed effects regression, we calculate the burn probability from 2001 to 2017 in points sampled from grazed and ungrazed properties in each region in grasslands, shrub/scrublands, and forests. We find that in the Central Coast and North Bay, annual burn probability decreases as stocking levels increase across all vegetation types, with reductions of 0.008-0.036. In the Central Valley and Foothills, the relationship is complex, with burn probability increasing over some grazing levels and variations in the effect of higher stocking densities. Our results indicate that livestock grazing may reduce annual burn probability in some regions and ecosystems in California, providing the first large-scale assessment of this relationship.

Recognition and precarious mobilities: The experiences of university students from a refugee background in Australia.

This article employs the concepts of recognition and precarious mobilities to understand university education for people from a refugee background. The authors draw on their ongoing qualitative longitudinal narrative enquiry exploring the experiences of 22 students in Australia from asylum-seeking backgrounds during their three-year study for a Bachelor's degree. Theories of recognition informed by the work of Axel Honneth and Nancy Fraser provide a conceptual framework for analysing the students' experiences in navigating government and institutional policies and practices which often fail to recognise the unique needs of this distinct group. Few higher education institutions fully acknowledge the educational capital and transnational understandings that students from refugee backgrounds develop through navigating precarious mobilities. Instead of receiving recognition for these assets, such students often feel they do not belong in higher education in the host society. Thus, belonging, an essential component in supporting their success in higher education and settlement, is undermined. To appreciate how university practices are informing student experiences, the authors explore two competing discourses: "the education of international students is Australia's third-largest export" on the one hand, and "higher education should be made available to all who can benefit from it" on the other.

Reconnaissance et mobilités précaires : expériences d'étudiants issus de milieux de réfugiés en Australie ­ Cet article s'appuie sur les concepts de reconnaissance et de mobilités précaires pour comprendre l'enseignement universitaire destiné à des personnes issues de milieux de réfugiés. Les autrices s'appuient sur l'étude narrative qualitative longitudinale qu'elles mènent actuellement et qui porte sur les expériences vécues en Australie par 22 étudiants issus de milieux de demandeurs d'asyle durant leurs trois années d'études en cursus de bachelor. Les théories de la reconnaissance orientées par les travaux d'Axel Honneth et de Nancy Fraser leur fournissent un cadre conceptuel pour analyser les expériences qu'ont vécues ces étudiants face à des politiques et pratiques gouvernementales et institutionnelles qui omettent souvent de reconnaître les besoins uniques du groupe particulier qu'ils forment. Peu d'établissements d'enseignement supérieur reconnaissent pleinement le capital éducatif et les notions transnationales qu'acquièrent les étudiants issus de milieux de réfugiés au travers de mobilités précaires. Loin d'être reconnus pour ces acquis, ils ont souvent l'impression de ne pas être à leur place dans l'enseignement supérieur de leur société d'accueil. Par conséquent, le sentiment d'appartenance, élément essentiel pour les aider à réussir dans l'enseignement supérieur et à s'installer, s'en trouve affaibli. Pour évaluer la façon dont les pratiques universitaires façonnent les expériences vécues par les étudiants, les autrices se sont penchées sur deux discours concurrents : d'une part, « l'éducation des étudiants internationaux est le troisième secteur d'exportation en Australie ¼ et d'autre part, « l'enseignement supérieur devrait être rendu accessible à tous ceux qui peuvent en profiter ¼.

Applying ecological site concepts and state-and-transition models to a grazed riparian rangeland.

Ecological sites and state-and-transition models are useful tools for generating and testing hypotheses about drivers of vegetation composition in rangeland systems. These models have been widely implemented in upland rangelands, but comparatively, little attention has been given to developing ecological site concepts for rangeland riparian areas, and additional environmental criteria may be necessary to classify riparian ecological sites. Between 2013 and 2016, fifteen study reaches on five creeks were studied at Tejon Ranch in southern California. Data were collected to describe the relationship between riparian vegetation composition, environmental variables, and livestock management; and to explore the utility of ecological sites and state-and-transition models for describing riparian vegetation communities and for creating hypotheses about drivers of vegetation change. Hierarchical cluster analysis was used to classify the environmental and vegetation data (15 stream reaches × 4 years) into two ecological sites and eight community phases that comprised three vegetation states. Classification and regression tree (CART) analysis was used to determine the influence of abiotic site variables, annual precipitation, and cattle activity on vegetation clusters. Channel slope explained the greatest amount of variation in vegetation clusters; however, soil texture, geology, watershed size, and elevation were also selected as important predictors of vegetation composition. The classification tree built with this limited set of abiotic predictor variables explained 90% of the observed vegetation clusters. Cattle grazing and annual precipitation were not linked to qualitative differences in vegetation. Abiotic variables explained almost all of the observed riparian vegetation dynamics-and the divisions in the CART analysis corresponded roughly to the ecological sites-suggesting that ecological sites are well-suited for understanding and predicting change in this highly variable system. These findings support continued development of riparian ecological site concepts and state-and-transition models to aid decision making for conservation and management of rangeland riparian areas.

Implications of changing spatial dynamics of irrigated pasture, California's third largest agricultural water use.

Irrigated agriculture is practiced on 680 million acres worldwide. Irrigated grazing land is likely a significant portion of that area but estimating an accurate figure has remained problematic. Due to its significant contribution to agricultural water use worldwide, we develop a methodology to remotely sense irrigated pasture using a California case study. Irrigated pasture is the third largest agricultural water use in California, yet its economic returns are low. As pressures mount for the agricultural sector to be more water efficient and for water to be directed towards its most economically valuable uses, there will likely be a reduction in irrigated pasture acreage. A first step in understanding the importance of irrigated pasture in California is establishing a methodology to quantify baseline information about its area, location, and current rate of loss. This study used a novel object-based image analysis and supervised classification on publicly-available, high resolution, remote sensing National Agriculture Imaging Program (NAIP) imagery to develop a highly accurate map of irrigated pasture in a rural county in California's Sierra foothills. Irrigated pasture was found to have decreased by 19% during the ten-year period, 2005-2014, from 4,273 to 3,470 acres. The implications of this loss include potential impacts to wetland-dependent species, groundwater recharge, game species, traditional ranching culture, livestock production, and land conservation. Overall accuracy in classification across years was consistently over 89%. Comparing these results against available measurements of irrigated pasture provided by state and federal agencies reveals that this method significantly improves upon existing metrics and methods of data collection and points to critical needs for new targeted research and monitoring efforts. Broadly, the analysis presented here provides an improved methodology for mapping irrigated pasture that can be extended to provide accurate and spatially-explicit data for other counties in California and other arid and semi-arid regions worldwide.