This study focuses on the constraints, adaptations and innovations in the livelihoods of Orma pastoralists. The fieldwork took place with families around Tiltila, Waldena and Kalalani over a period of 9 months in 2007/08. The position of pastoralist peoples in East Africa is characterised by social, political and economic marginalisation, weak land tenure, and declining per capita livestock holdings, while their shrinking grazing lands are widely regarded to be on the front line of climate change, both in terms of climate impacts and biofuel/agribusiness land pressure. The dearth of good quality data on pastoralist populations and livelihoods is widely cited as one of the fundamental barriers to improving the effectiveness of development support in the drylands. This study seeks to address these knowledge gaps for Orma pastoralists, while contributing to the body of theory on pastoralist livelihood dynamics. Data on the effects of wealth, education and food aid on household mobility were analysed using a theory of asset threshold dynamics. An adapted typology of livelihood strategies was developed to interpret and structure the data. Using child mortality as a proxy for respondent health, the impacts of wealth and mobility status on families’ health were explored. In the context of an almost total lack of data on community redistribution of food aid, both for the Orma and for East African pastoralists more generally, the study provides empirical data on de facto community food aid allocation patterns. The study also examines a controversial large-scale expropriation of land in Tana River (subsidised under the Kyoto Protocol’s Clean Development Mechanism) which will undermine the capacity of Orma pastoralists and other minority groups, to adapt to increased and more extreme environmental variability. In an environment in which enrolment in formal education is very low (particularly for girls), the study found that community nursery schools represent a relatively recent (and thus far undocumented) innovation organised and funded by groups of parents. The data demonstrates unprecedented levels of female enrolment despite cost constraints faced by least wealthy families. It is therefore suggested that incorporation of the community nursery model into the basic literacy element of the proposed national distance learning strategy, offers significant potential for addressing ‘Education For All’ in Kenya’s drylands.

This Thesis explored a range of approaches to study the uncertainty and impacts associated with climate change at the farm scale in Scotland. The research objective was to use a process of uncertainty evaluation and simulation modelling to provide evidence of how primary production components of agriculture in Scotland may change under a future climate. The work used a generic Integrated Modelling Framework to structure the following sequence of investigations: Evaluate a Regional Climate Model‟s hindcast estimates (1960-1990) against observed weather data; Develop bias correction „downscaling factors‟ to be applied to the Regional Climate Model‟s future estimates; Evaluate the impacts of weather data sources (observed and modelled) on estimates made by a cropping systems model (CropSyst); Estimate values for a range of agro-meteorological metrics using observed and estimated downscaled future weather data; Simulate spring barley and winter wheat growth using CropSyst with observed and modelled weather data; Develop CropSyst in order to represent grass growth, evaluate estimates against a set of a priori criteria and determine suitability for use in a whole farm model. Conduct counter-factual assessments of the impacts of climate change and potential adaptation options using a whole farm model (LADSS). The study aimed to use tools on a spectrum of land use modelling complexity: agro-meteorological metrics (simple), CropSyst (intermediate), and the whole-farm integrated model (complex). Such an approach had a path dependency, in that to use the livestock system model component within the whole farm model, CropSyst had to make estimates of an acceptable quality for grass production. CropSyst however failed to meet the a priori evaluation criteria. This, coupled with technical and time constraints in running LADSS, led to the decision not to run the whole farm model. The findings were organised within the concepts of resilience and adaptive capacity. Results gained showed that the HadRM3 Regional Climate Model was capable of making both good and poor estimates of weather variables in the UK, and that downscaling improved the match between hindcast and observed weather data significantly. A sensitivity analysis involving introducing uncertainty from weather data sources within CropSyst showed that care was needed in interpreting estimates of future crop production. The agro-meteorological metrics indicated that whilst growing season length increases, the date of end of field capacity does not. The projected changes in crop production will likely be more positive if crop responses to elevated CO2 are considered. However, there will be additional constraints on crop growth due to increases in duration and magnitude of periods of growth limiting soil water deficits. Without adaptation to crop varieties with slower phenological development, yield decreases are seen in spring barley and winter wheat. The thesis concludes, whilst recognising the caveats and limitations of the methods used and the multiple range of external influencing issues, that the biophysical impacts at the farm scale in Scotland are within the boundaries of resilience, given that achievable adaptation options exist and are undertaken. The dynamics of farm scale management will need to adjust to cope with higher levels of water stress, but opportunities will also arise for greater flexibility in land use mixes. Crop yield can increase due to more favourable growing conditions and cultivar adaptations. These conclusions, when placed within the context of climate change impacts and adaptive cycles at a global scale, indicate that agriculture in Scotland has the potential to cope with the impacts but that substantial changes are required in farming practices.

Interactions between host plants and aphids under water stress conditions were examined. Two controlled environment room studies, a Veld experiment and phenological modelling analysis were used to investigate three different plant-aphid relationships. The aim of these studies was to determine the results of water shortage on plant and pest populations, which are likely to result under climate change scenarios. The central hypothesis was that mild drought stress would lead to greater aphid populations through a beneficial increase of small nitrogenous molecules in the phloem sap providing improved diet quality — the Plant Stress Hypothesis (White, 1969). Myzus persicae (the peach–potato aphid) is a broad-range feeder with a preference for senescent foliage. Contrary to expectations, on young cabbage plants, Brassica oleracea var capitata, it was found to increase faster and to a greater extent on well-watered hosts. Aphids were also found to prevent osmoregulation in droughted plants. Despite this, the aphid infestation led to a drought-like response in all plants irrespective of watering regime, causing significantly reduced growth. Metopolophium dirhodum (the rose–grain aphid) overwinters as eggs on Rosa spp. but most of its life-cycle is spent on grasses and cereal crops. As with M. persicae, aphid infestation caused drought-like symptoms even in well-watered plants. The mechanism of reduction in plant health is most likely through aphid damage to the efficiency of Photosystem a within 7 days of infestation. On young barley plants, Hordeum vulgare, the rose–grain aphid was found to increase faster and to greater extent on droughted hosts. In contrast to M. persicae, the study strongly supported the Plant Stress Hypothesis, Finding that even mild water stress of approximately −0.3 MPa could lead to conditions favourable to rapid aphid population increase. The difference in the response of different species of aphids may be associated more with the levels of soluble nitrogen in their diet than specifically host plant water status. Drepanosiphum platanoidis is an aphid specific to sycamore, Acer pseudoplatanus and spends its entire life-cycle on that species. In the Veld, the total number of aphids supported by a single tree was found to correlate most strongly with soluble leaf nitrogen. In addition, the number of aphids on individual leaves was found to correlate strongly and negatively with stomatal conductance and leaf water potential. Finally, analysis of historical aphid suction-trap data was carried out. UK Rothamsted suction-traps are 12.2 m tall and sample air at 0.75 m3 s-1, with daily aphid sampling between April and November. The traps are designed to catch the largest proportion of aphids in the total insect sample and to reduce the effect of surrounding land-use on the sample. The area represented by a trap may be as much as 700 km2 (Harrington and Woiwod, 2007). The dataset is the longest and most geographically extensive for aphid populations, comprising 46 sites across Europe as of 2011. In this analysis, aphid and meteorological data from the Edinburgh East Craigs site were used. This also enabled comparison with D. platanoidis numbers collected in the Veld, which showed a strongly significant positive relationship between the two. Since the data collected in suction-traps are correlated with numbers in the Veld, aphid population analysis can be improved with use of these longer datasets, without reliance on shorter-term Veld surveys. The various population characteristics examined were found to be strongly correlated with each other, but were unconnected to data from previous years. The date of first catch was found to be significantly advancing over time, with strong influences from daily minimum temperatures and vapour pressure deficits of the air within the year. Higher temperatures with lower humidity tend to bring forward the date of first catch. Lower tends to depress the population in the summer. The overall hypothesis that mild drought would benefit aphid populations cannot be accepted, but in two cases of the experiment sections of the work there were strong relationships between aphid numbers and both leaf temperature and soil moisture. The meteorological data analysis indicates that climatic changes towards a hotter, drier climate could substantially alter population dynamics. Harrington, R. and Woiwod, I. (2007). Foresight from hindsight: The Rothamsted Insect Survey. Outlooks on Pest Management, 18, 9–14. White, T. (1969). An index to measure weather-induced stress of trees associated with outbreaks of psyllids in Australia. Ecology, 50, 905–909.

There is currently widespread concern about the impact of continuing climate change on the distribution, and ultimately persistence of species across all the major taxa. While much previous work has focussed on using climate envelope models to make projections of the location of potential future suitable climate space for a variety of species, these can at best give an indication of the likely direction and potential magnitude of distributional change. They lack information on spatial population dynamics, dispersal, habitat suitability, local adaptation and inter-specific interactions. The aim of this thesis was to explore how some of these other factors might alter projections regarding species’ distributional change in response to climate change, using both theoretical models, and garden warbler (Sylvia borin) as a model system. A key aspect which has been largely over-looked until very recently is the complex range dynamics which can result from spatial variation in population dynamics, and the impacts of inter-annual variability rather than simply mean climate, both of which can impact extinction risk. Much insight into future impacts of climate change can also be gained through studies of past distributional changes, such as that observed in the British breeding population of garden warbler in the last three decades. In many cases, studies at smaller-scales are necessary to elucidate the mechanisms of climate change impacts and further explore potential synergies with other drivers of ecosystem change such as habitat loss and species invasions. The particular combination of factors which should be included to make projections of distributional change will be species-specific and scale-dependent, therefore modelling exercises should be carefully designed depending on the intended outcome for conservation.

At present, species are faced with a host of human-induced impacts that have already led to a loss of biodiversity and shifts in species’ ranges. Knowledge of the ecological and evolutionary processes of dynamic species’ ranges, that are either shifting or expanding, will be key to understanding the ability of species to persist and adapt during periods of environmental change. The aim of this thesis is to investigate the effects of range expansion on the genetics and evolution of species, and understand the processes that facilitate the spatial spread of populations. Using individual-based simulation models, this work demonstrates that the unique selective environment of range expansion can have a significant effect on spatial genetics and the evolution of life-history traits. It is found that the survival and spread of mutations, of various fitness effects, is influenced substantially by landscape features encountered by the expanding range. The incorporation of more specific genetic architecture shows that a substantially increased frequency of fitness peak shifts may occur on the edge of an expanding range than would arise within a stationary population. Range expansion is shown to select for increased dispersal and reproduction at the expense of competitive ability on the front of the expanding wave which results in an accelerating spread rate. The survival and spread of a population during range expansion is also affected substantially by the specific movement behaviour of individuals. The exact nature of suitable habitat, in terms of the number of suitable habitat patches and level of fragmentation, will also greatly affect the ability of a population to survive and spread during a period of environmental change. These findings are synthesised within a conceptual framework that is proposed for the evolution of populations during range expansion, where a flattening of the fitness landscape leads to adaptive revolutions.

With the retreat of the state under neoliberalism, the lack of (or negligible) government and non-governmental support reasserts grassroots initiatives as a global-change strategy. A feminist political ecology approach and the concept of adverse inclusion were used to facilitate an analysis of social differences shaping local-level adaptive responses. Adaptive responses of small farmers in the border village of San Ignacio, Sonora, Mexico, who are increasingly vulnerable to climate change, water scarcity, and changing labor markets were studied. Gender differences in production sites translate into diverse vulnerabilities and adaptive strategies. Local capacities and initiatives should be a focus of research and policy to avoid viewing women and men as passive in the face of global change. The dynamic strategies of San Ignacio women and men in home gardens and small orchards hold lessons for other regions particularly related to adaptation to climate change via agrobiodiversity, water resource management, and diversified agricultural livelihoods.

Climate change forecasts tell of significant challenges ahead for agrifood systems at all scales, from global to highly local. Farmers are often at the forefront of these challenges. How farmers perceive climate related risks, and the actions they take to protect or adapt their lives and livelihoods are therefore a critical area of inquiry. The purpose of this dissertation is to describe how farmers in Vermont, in the Northeastern U.S., think about climate change, and how their experiences and perceptions influence engagement with adaptation or mitigation activities. To this end, my research questions included: (1) what are farmers already doing to address climate impacts on their farms? (2) Do farmers perceive climate change to be a risk, and if so what are they doing to address it? (3) Are farmers and agricultural technical service providers in agreement about the current performance of climate change adaptation strategies? (4) Can a qualitative typology of farmers describe the degree to which they are resilient in the face of climate change? I conducted this research in the context of a larger, collaborative effort called the Vermont Agricultural Resilience in a Changing Climate Initiative (VAR), based at the University of Vermont. VAR served as an umbrella for transdisciplinary, participatory action research activities that capitalized on a diversity of perspectives and expertise, including the embedded knowledge of farmers and agricultural technical service providers. The VAR team as a whole and in sub-teams utilized a selection of research approaches including preliminary research activities that contributed to the development of research questions addressed in this dissertation, and primary research approaches used to answer those questions. This dissertation report consists of the following chapters: Chapters 1-2 present and introduction and background information related to climate change and agriculture, including a review of national, regional and site conditions as well as an overview of research purpose, approaches, methods, and theoretical frameworks applicable to the exploration of the questions and interpretation of findings. Chapters 3-6 address the following topics: (1) a case study in transdisciplinary participatory action research applied to climate change and agriculture in Vermont, (2) an analysis of farmer perceptions of climate related risk and associated on-farm adaptation strategies, (3) a report of farmer perceptions of climate change and comparison of farmer and technical service provider evaluations of potential climate change best management practices, and (4) a qualitative typology of farmer resilience. This research is some of the first to address these topics from the perspective of farmers in the Northeastern U.S. Through these chapters, an important story is told about role that climate change plays in farm management today. The broader application of these findings is in the design of thoughtful programming and policies that support agrifood system resilience. I argue that social programs and policies that address agriculture and climate change should be informed by the experiences of farmers. When we weave together the knowledge of agricultural practitioners and our best scientific knowledge, we can better prepare for the changes in agrifood systems that a changing climate will require of us.

The problem of food insecurity in developing countries is an enormous challenge. In rural communities, it is a perennial problem that requires undivided attention to ensure household food security. This paper seeks to define the role of rural participation in providing household and community food security with a particular focus on Lower Gweru irrigation project in Zimbabwe. The research comes in light of increased food deficit in Zimbabwe that has been compounded by failed politics, climate change and weather extreme events. Data was gathered using self-administered questionnaires, direct observation and literature review. Data was analysed using the Microsoft Excel 365 ToolPak and Health24 Web Calculator. This paper highlights the importance of rural irrigation schemes in addressing community and household food security and ensuring health nutrition uptake by irrigators and surrounding communities. Rural irrigation systems enable farmers to become net food sellers allowing them to benefit from food price volatility. It also highlights the resultant development and makes recommendations for future irrigation developments

Today, climate change and rapid ecological change are impacting our ecosystems and landscapes in numerous, often surprising ways. These changes result in social, cultural, ecological, and economic shifts, as exemplified in the climate-exacerbated mountain pine beetle (MPB) outbreak in British Columbia. Recently, scientific communities have boosted calls for “usable science.” By interviewing leading MPB scientists, I ask, “How are scientists and their institutions responding to rapid ecological change?” Numerous factors shape MPB science—institutional support, funding, and values—and these factors enable and constrain effective relationships and ultimately, useful science, in response to the outbreak. Results suggest that while science and scientific institutions change slowly, and while relationships between MPB science and policy are characterized as tenuous, there are signs that crossing institutional boundaries (such as the TRIA Network) contributes to producing science that is more effective for responding to rapid ecological change. / Graduate

<p>The Arctic Ocean and Western Antarctic Peninsula (WAP) are the fastest warming regions on the planet and are undergoing rapid climate and ecosystem changes. Until we can fully resolve the coupling between biological and physical processes we cannot predict how warming will influence carbon cycling and ecosystem function and structure in these sensitive and climactically important regions. My dissertation centers on the use of high-resolution measurements of surface dissolved gases, primarily O2 and Ar, as tracers or physical and biological functioning that we measure underway using an optode and Equilibrator Inlet Mass Spectrometry (EIMS). Total O2 measurements are common throughout the historical and autonomous record but are influenced by biological (net metabolic balance) and physical (temperature, salinity, pressure changes, ice melt/freeze, mixing, bubbles and diffusive gas exchange) processes. We use Ar, an inert gas with similar solubility properties to O2, to devolve distinct records of biological (O2/Ar) and physical (Ar) oxygen. These high-resolution measurements that expose intersystem coupling and submesoscale variability were central to studies in the Arctic Ocean, WAP and open Southern Ocean that make up this dissertation. </p><p>Key findings of this work include the documentation of under ice and ice-edge blooms and basin scale net sea ice freeze/melt processes in the Arctic Ocean. In the WAP O2 and pCO2 are both biologically driven and net community production (NCP) variability is controlled by Fe and light availability tied to glacial and sea ice meltwater input. Further, we present a feasibility study that shows the ability to use modeled Ar to derive NCP from total O2 records. This approach has the potential to unlock critical carbon flux estimates from historical and autonomous O2 measurements in the global oceans.</p> / Dissertation