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Lassa fever is a zoonotic viral hemorrhagic fever endemic to West Africa. Currently, no approved and commercially available human vaccine exists to prevent Lassa fever. In addition to human vaccines to control Lassa fever, research efforts have suggested that vaccination of the reservoir host rodent species may be an effective alternative, especially new vaccine technologies such as self-spreading or transmissible vaccines. To date, very little research exists related to the sociological barriers to adoption of wildlife vaccination or perceptions of these new vaccine technologies in West Africa. To identify effective intervention strategies including development of reservoir host vaccination by both traditional and potentially self-disseminating approaches, this study sought to assess the knowledge, attitudes, and perceptions of community members and other key stakeholders.To assess these factors, 203 individual interviews and 20 focus group discussions were conducted across 22 communities in Sierra Leone and analyzed using quantitative and qualitative methods. Survey participants were asked questions related to their previous experiences with human and animal vaccines, knowledge and risk perception of viral disease, and willingness for nearby wildlife to receive traditional and self-disseminating vaccines.Almost all study participants (94%) were aware of Lassa fever, although the majority (62%) perceived the disease to be low risk. However, this perception was not correlated with a hesitancy toward preventive measures, as 94% of respondents said they would accept a human Lassa fever vaccine if offered and 98% said they would allow rodents in their homes to be vaccinated. Out of the 203 individuals surveyed, 201 said they would allow rodents to receive a self-disseminating vaccine if it would prevent disease. While attitudes toward self-spreading or transmissible vaccination are generally positive, respondents raised genuine concerns about the feasibility of the technology, its impact on traditional consumption of rodent meat, and potential negative effects to adjacent animal and human populations. Focus group discussions revealed further cultural considerations tied to vaccine hesitancy, including the impact of community education, role of religion, and best communication platforms for health messaging.This study suggests that when developing new disease prevention technologies, it is critical to work together with intended beneficiaries, socialize key concepts, and co-create strategies that effectively address all concerns to health, safety, and equity. Additionally, the high levels of trust and reliance on hierarchical systems of power and responsibility in study communities point to the essential need for robust regulatory frameworks to guide the development and potential implementation of new technologies. Further participatory research is needed to expand upon the findings of this study and continue developing shared knowledge and understandings of community knowledge, attitudes, perceptions, and practices related to viral zoonotic disease and human and animal vaccines.

Rangelands are landscapes of uncertainty. Their management as “extensive” yet expansive agricultural landscapes is challenged by high temporal and spatial variability alongside unprecedented climatic, economic, and cultural uncertainties, including reliance on annual grasses with highly seasonal and variable NPP, increasingly common and worsening drought conditions, policy change and impacts, and a growing anti-cattle sentiment among some groups. Cattle overgrazing, along with intensification, has contributed to the significant loss of soil organic carbon (SOC) on rangelands, turning one of the most important terrestrial carbon sinks into a source of CO2. While well managed grazing could help to sequester SOC and aid in climate change mitigation, the impact of grazing on rangeland SOC on, including how to measure SOC change with such high spatial heterogeneity, is understudied and poorly understood. Further, ultimately climate change mitigation relies on widespread adoption by ranchers, who are situated within complex social-ecological systems and must be responsive not only to ecological uncertainties (such as drought), but also to social and economic uncertainties such as changing social norms, declining profitability, and precarious land access. My dissertation research combined optimizing analytical measurement of SOC on rangelands, an ecological assessment of the impact of different forms of grazing management on SOC, and a social science approach to understand both the factors driving adoption of grazing management practices for SOC sequestration as well as the barriers and challenges ranchers face. The first chapter of my dissertation examined the challenges of measuring SOC on heterogeneous agricultural landscapes. Using soil samples from California crop and rangelands, I analyzed how spatial heterogeneity, analytical variability, compositing, and statistical analyses affects the power, reliability, and validity of SOC measurements. I demonstrate that (1) spatial heterogeneity is a primary driver of uncertainty; (2) dry combustion analyzers have relatively low uncertainty, although inorganic C can increase error; (3) Student’s t-test and its relatives can be unreliable for drawing inferences about changes in SOC stocks; and (4) in heterogeneous agricultural landscapes, common sample sizes of 10–30 cores cannot reliably detect the modest changes in SOC that a few years of common management interventions are expected to produce. Results highlight the challenges of measuring small SOC changes on highly heterogeneous rangelands. Lastly, I recommend several improvements that will be necessary for reliably monitoring SOC, especially for research and C markets, including using a priori spatial information to determine necessary sample sizes, minimizing compositing, and using non-parametric statistical tests in scenarios where t-tests may be unreliable. Chapters 2 and 3 of my dissertation focused on adaptive multi-paddock (AMP) grazing, which is a form of short-duration, high intensity grazing that centers principles such as adaptive management, animal rotations and incorporating pasture rest. AMP ranchers are often associated with Holistic Management (HM), which is a decision making framework and training program that teaches ranchers AMP grazing practices alongside principles such as systems based thinking for managing complexity, ecological monitoring, and maximizing flexibility and adaptability. Both AMP grazing and HM have been the subject of much research interest, but studies have been conducted in ecological and social science disciplinary silos. In Chapter 2, I investigated the impact of AMP grazing on SOC stocks, SOC stabilization in four functionally distinct soil organic matter fractions, and plant community composition across northern California rangelands. My results demonstrate that, compared to conventionally (CONV) grazed ranches, three of four AMP grazed ranches contain significantly greater SOC in surface soils, and two of four contain significantly greater SOC stocks down to 100cm. The greater SOC on AMP grazed ranches was contained in the MAOM fraction, which is the most persistent form of SOC, with implications for climate change mitigation. Plant community composition varied by site – some AMP grazed ranches had greater composition of perennial vs annual grasses and overall less bare ground, but these findings were not universal. Lastly, in Chapter 3, I conducted semi-structured interviews with AMP and CONV ranchers to understand how AMP grazing relates to ranchers’ mental models, including decision making processes, motivations, barriers, and how the combination of AMP-HM helps these ranchers respond to increasing challenges and uncertainties. Our findings suggest that AMP-HM shifts ranchers' approaches towards ones that involve more ‘holistic,’ systems based thinking, in two ways: 1) through its emphasis on monitoring combined with increased interaction with their land and animals, which changes the ways ranchers see and understand their management, and 2) by increasing ranchers’ agency to operationalize these new mental models through its decision making framework and trainings. Together, these two facets culminate in a common suite of strategies used by AMP-HM ranchers, which they view as key to ranching profitably and sustainably in the face of climatic, economic, and cultural challenges. Altogether, this dissertation highlights the measurement needs for monitoring, and the grazing management opportunities, for increasing SOC on California rangelands. The social-ecological approach taken in this research also illuminates ranchers’ experiences with AMP grazing management and SOC sequestration, which will help improve will world applicability of this research. Importantly, results of this work demonstrate the opportunity for sequestering and stabilizing SOC through AMP grazing management on California rangelands – which could bolster climate change mitigation efforts and improve ranchers’ ability to sustain future uncertainties.

While most restoration projects to date have focused on a specific system in a specific location and are rarely greater than 5,000 hectares in extent, calls for restoration at broader scales with a focus on restoring complexity, and in diverse ecosystems are growing. However, ecological restoration at broader scales, encompassing multiple habitat types, management goals, and complex cross-scale interactions presents its own suite of challenges. To address these challenges I first developed a long-term adaptive ecological monitoring framework for landscape restoration projects. Then I assessed changing fire regimes in California woodlands at regional scales and how this may influence current vegetation structure. I also evaluated the current conditions and restoration needs of California’s iconic and extensive Blue oak woodlands and savannas.

On California's Mediterranean rangelands, cattle ranching supports the conservation of threatened and endangered species; however, ranchers are generally not compensated for providing this ecological service or beneficial natural process. Instead, the provision of ecological services, including species conservation, relies on livestock production-- primarily beef cattle production-- to sustain beneficial grazing and rancher stewardship. Poor economic returns, production losses from weather, fire, or other causes, loss of access to forage, and conflict from the demands of a growing population put livestock ranching at risk in California. To understand how beef production can be sustained to provide ecological services, it must be understood as a social-ecological system (SES), where people and their activities work within and use nature. In three research studies, I used mixed methods and qualitative research methods to examine key aspects of the social-ecological system framework that describe ranching in California and the San Francisco Bay Area. First, using document review, I studied ranching activities or the SES interactions that impact species conservation. Second, through interviews, survey, direct observation, and big data analysis of all recorded cattle movements in the state over two years, I considered the SES actors by examining the function of the production system that support ranching or rancher-livelihood requirements. In a final study, I conducted spatial analysis to document the role of grazing land in species conservation. I also examined case studies of exacted easements to assess impacts of a governance strategy for land protection increasingly impacting SESs on grazing lands. Overall, the research revealed that land sharing, a conservation strategy for conservation in concert with agricultural production, is demonstrated on California's grazing lands. However, relationships between conservation, livestock production, and the people involved in managing grazing lands are varied and complex. A review of United States Fish and Wildlife Service's listing documents indicated that 143 species (51% of federally listed plant and animal species in California) are found in habitats with grazing. While livestock grazing is stated to threaten 73% of these species, 59% of these species positively benefit from livestock grazing, with substantial overlap where species are both threatened by and benefit from grazing. Most threats result from overgrazing, while benefits result from grazing providing and maintaining habitat structure and ecosystem function in the management of the state's novel vegetation. Benefits to some species are provided across all of California's terrestrial habitats except alpine.Extensive livestock grazing systems in California, providing benefits for species conservation, were found to be supported by the integration of production systems. Transportation and marketing enable ranchers, from small-scale to larger producers, to strategically move cattle to optimize production within a variable climate. Over 500,000 head, 47 percent of the state's calf crop leave extensive grazing lands in California and are moved to new pastures or feedyards over a 12-week period each year. Rancher interviews indicated that cattle are moved around and sold off grazing land in response to change in forage quality and quantity. These movements support their interest in managing for conservation objectives. Research results found that saleyards and cattle buyers drive efficiency by sorting, pricing, and moving cattle to match them to feed resources; however, transactions lack traceability to inform policy and consumer choice.While beef production systems provide economic value for ranching and support ranchers' ability to manage grazing lands for conservation benefits, land protection strategies meant to support conservation on grazed lands can deprivilege livestock production. Exacted easements, which support development on some land through compensatory mitigation, provide for the conservation of threatened and endangered species by protecting other land. Exacted easements are increasingly viewed as a tool to conserve ranching, especially in areas like the San Francisco Bay Area, where much of the high-value conservation land is grazing land. These easements result in reterritorialization; land use is redefined, and land management activities may be restricted. However, they also create accumulation from conservation by providing new economic values from conservation services, which both challenge and support a rancher's place on the landscape and land sharing.As revealed and described by the three research studies presented in this dissertation, cattle ranching on California's rangelands is a social-ecological system (SES), where ranchers steward land and manage grazing. Interactions in the SES, primarily livestock grazing, support ecological services like conservation of imperiled species conservation but rely on the rancher’s ability to move livestock though transportation and markets to manage resources and provide economic viability. The SESs is economically viable through its contributions to beef production. Nevertheless, beef production in California and globally has a large footprint with consequences for human and animal welfare, environmental health, and nature conservation. To maintain a social license to continue producing beef, research needs to inform efficient and sustainable beef production practices, and the value of ecosystems services supported by beef production should be determined and understood.

Riparian areas in arid rangelands provide a wide range of ecosystem services and are critical areas for conservation of landscape and regional biological diversity. Creeks and their associated riparian habitats also provide unique resources for livestock management, however these systems have proven to be sensitive to disturbance from livestock. Ecological site concepts and associated state-and-transition models are useful tools for understanding rangeland plant succession and the relative influence of management actions. These models have been widely developed for upland rangeland systems; however, extension of these models to rangeland riparian systems is still in its infancy. In this study I classified two ecological sites along four streams on the Tejon Ranch in the southern San Joaquin Valley, California. Using vegetation data gathered over four years at fifteen study reaches I identified three distinct vegetation states and plausible conditions precipitating transitions between states. I monitored large mammal and herpetofauna activity at each of the study reaches and compared the predictive power of the categorical ecological site and state-and-transition models in predicting wildlife activity to models based on continuous environmental variables. Finally I investigated the role of cattle and feral pig management on riparian vegetation and wildlife. Ecological sites proved to be a good predictor of observed wildlife community assemblages and was included in top models predicting activity of three of five mammal species: bobcat (Lynx rufus) deer (Odocoileus hemionus) and feral pig (Sus scrofa); and two of three reptile species: western fence lizard (Sceloporus occidentalis) and Gilbert’s skink (Plestiodon gilberti). In contrast, vegetation states proved to be a poor predictor compared to continuous variables. Cattle and feral pigs appear to have played a role in the one observed vegetation transition, and cattle and feral pig activity was correlated with increased cover of hydrophyllic vegetation and bare soil, and decreased cover of upland vegetation and forbs. Summer cattle activity and spring pig activity were the most strongly correlated with changes in vegetation attributes. Results from this study illustrate the utility of ecological sites to model riparian vegetation change and provide a framework for understanding the effect of rangeland management on riparian vegetation and wildlife.

Grasslands in California's inland Mediterranean climate zone vary greatly over time and space, largely due to fluctuating rainfall and heterogeneous geology, topography, and soils. In light of a dramatic invasion of exotic species into these grasslands, conservation management goals typically include the preservation and enhancement of native vegetation. Developing specific management targets to achieve these goals, however, is complicated by uncertainty about pre-invasion conditions and the spatial and temporal complexity of the system. The Tejon Ranch, the largest, contiguous, privately-owned property in the state, supports 44,000 ha of California's inland Mediterranean grassland. The mission of the Tejon Ranch Conservancy (Conservancy) is to preserve, enhance, and restore the native biodiversity of Tejon Ranch. In 2009, the Conservancy partnered with the University of California Range Ecology Lab led by James Bartolome to describe the grasslands on the ranch, in order to build the understanding required for management planning. As a doctoral researcher and co-leader of the study from 2010 to 2014, my objective was to develop a scientific framework to inform reliable predictions about the distribution of plant species over space and time in the ranch's grasslands. I investigated three basic questions: 1.Does species composition correlate with geologic, topographic, and edaphic landscape composition, at differing spatial scales?2.What are the drivers of inter-annual community change at the ecological site scale?3.What are the alternative states of the ecological sites?Chapter 1 is a description of how I investigated the first question in the western Mojave Desert landscape of the ranch. I collected topographic, edaphic, and ground cover data at 35 small (0.25 m2) plots across a 64 km2 (6.4 x 107 m2) extent in the spring of 2010. Fortuitously, the timing and amount of rainfall in 2009-2010 resulted in high diversity and abundance of native annual forbs and grasses across the landscape. I encountered 46 species; all were annuals except for three perennial bunchgrass species in 9 plots. I found that elevation, soil cation exchange capacity, soil silt percentage, and soil total nitrogen explained 40% of the spatial variation of the 25 species encountered at more than one plot. I identified nine distinct species assemblages, four with plant cover dominated by native annual species, and five with plant cover dominated by exotic annual species. The five exotic assemblages were constrained to two geographic areas of the landscape. Both areas contained sediments from degraded dolomitic roof pendants of the Tehachapi Mountains and featured soils high in clay and nitrogen. I hypothesized that atmospheric nitrogen deposition is preferentially increasing soil nitrogen in these zones, promoting persistent exotic species dominance there. Overall, results suggested that species composition did in fact correlate with landscape composition, as perceived at the scales of geology type and landform, and measured at the smaller scale of the plot. I conclude by recommending that restoration management planning incorporate considerations of biogeochemical nitrogen cycling. In Chapter 2, I explain how the Range Ecology Lab and Tejon Ranch Conservancy investigated my first and second research questions in the San Joaquin Valley landscape of Tejon Ranch. Using thirty-five 3024 m2 study plots across a 294 km2 extent, we discovered that species distribution was more strongly correlated with geology, slope, and elevation than with USDA Major Land Resource Area or soil map unit. Accordingly, we used geology, slope class, and elevation class to divide the grasslands into 52 ecological sites (with 14 ecological sites representing physical conditions of 85% of the grassland area). With a focus on four geographically extensive ecological sites, I demonstrate how we verified the accuracy of our ecological site model, identified community types (i.e., community phases) at the ecological sites, and determined the drivers of community phase shifts between years at the ecological sites (i.e., community pathways). The Pleistocene terraces and Mafic bedrock slopes ecological sites each supported a single community phase in all three years. In contrast, at both the Holocene flats and the Miocene hills ecological sites, phase shifts were observed from 2010 to 2011, and again from 2011 to 2012. These inter-annual shifts in community phases were driven more strongly by variation in rainfall than by rodent bioturbation or livestock grazing. At both ecological sites, October and November rainfall exceeding 2 cm was a prerequisite for community phases dominated by exotic annual grasses, whereas less precipitation in those months promoted community phases with a higher relative abundance of native annual forbs. A concurrent wildlife study on the Holocene flats ecological site revealed that community phases with dense exotic annual grasses are unsuitable for a suite of special-status vertebrates. The Conservancy is using fall rainfall exceeding 2 cm as a cue to suppress exotic annual grass biomass using cattle grazing, in order to enhance conditions for native annual forbs and wildlife. This management prescription would not have been possible without organizing the landscape into ecological sites and tracking the grassland community on those ecological sites across multiple years. In Chapter 3 I describe how we explored my third research question. We used state-and-transition models to catalogue our understanding about historical and contemporary states at the four focal ecological sites in the San Joaquin Valley landscape of Tejon Ranch. Landscape reconnaissance revealed that all but the Pleistocene terraces currently support an alternative state in addition to the herbaceous state measured in 2010-2012 - one with greater relative cover of perennial grasses, shrubs, and/or oaks. Using soil phytoliths and historical accounts, we developed hypotheses about historical states (circa 1772) for the four ecological sites. We propose that the Holocene flats ecological site likely supported a native forbland with an open canopy of Atriplex sp., the Mafic bedrock slopes ecological site likely supported a forbland-oak savanna matrix, and the Pleistocene terraces and Miocene hills ecological sites likely supported grasslands dominated by perennial grasses. Using the state-and-transition models as guides, I describe potential restoration management for each ecological site. The Conservancy is currently spending limited restoration funds to enhance conditions for native annual forbs and wildlife in the current annual grassland state of the Holocene flats. However, significant recovery of native biodiversity appears possible on the Pleistocene terraces and Mafic bedrock slopes ecological sites, if the Conservancy elects to spend the time and money required to cross the thresholds from the current annual grassland states to alternative states on those ecological sites.