Atmospheric nitrogen deposition to the ocean has more than doubled in the past 150 years due to anthropogenic activity, reaching levels comparable with nitrogen fixation in the subtropical North Atlantic. Previous studies have suggested that atmospherically deposited N may increase export production, decrease surface water phosphate levels, and substantially impact geochemical estimates of nitrogen fixation. This dissertation reports on the magnitude and biogeochemical fate of soluble N and P deposition in the subtropical North Atlantic. Aerosol and wet deposition time-series samples were used to determine the fluxes, sources, and N:P ratios of atmospheric nutrient deposition. Based on the magnitudes of total soluble N and P deposition, atmospheric nutrients are estimated to supply ~10-50% of allochthonous N to the North Atlantic subtropical gyre. Samples gathered in Barbados, the Canary Islands, and Miami indicate that atmospheric N sources are primarily anthropogenic (and thus, increasing) and that P sources are primarily natural (and thus relatively steady). Because inorganic nutrient concentrations in surface waters are in the low nM range, increasing P stress in surface waters may occur as a result of increasing N deposition. This assessment is supported by modeling studies, which also indicate that deposition would enhance surface P depletion. Inorganic N contributes nearly all (85-87%) of atmospherically deposited soluble N; the majority (~60%) of the remaining soluble organic N is comprised of an incompletely characterized pool of volatile basic organic N. Water soluble organic P contributes ~20-50% of soluble P. Because organic P contributes a relatively higher portion of soluble P as compared to organic N, the inclusion of organic matter in deposition estimates could both enhance the expected level of export production and reduce the predicted levels of P stress induced by atmospheric deposition. Further modeling studies indicate that the fate of atmospheric nutrients in the subtropical North Atlantic is controlled by non-Redfieldian processes, and that atmospheric nutrients eventually accumulate in the main thermocline. The research presented here suggests that future increases in atmospheric N emissions could have long-term impacts on surface ocean biology and nutrient cycles in the subtropical North Atlantic.

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6 pp. / Hardly a week goes by without a major news story related to the global and local environment. Every one has heard of global warming and the climate changes being felt as average temperatures rise in most parts of the world. At the state and local levels we have all heard about the dwindling water resources how these might limit the future growth of Arizona. Without electrical energy (electricity) to keep cool and pump water life in our arid and semi-arid climates would become unbearable. What we often do not realize is that electricity production, water resources and global warming are all interconnected. By becoming more aware of the global issues that are confronting us, we will also become more sensitive to local and individual concerns. And by acting individually and locally we can have a positive impact in controlling the global issues that we all face. In the first page, this Bulletin hopes to bring renewed awareness to AZ residents and their need to conserve electricity in their daily lives by connecting their individual actions to local, state and global effects. The following topics will be introduced: Global Warming and its Local Impact Arizona Water Resources Electricity Production in Arizona The second page will be devoted to providing energy saving tips at home by providing a primer of basic electricity concepts, how to measure electricity usage at home, examples of wasted electricity, and tips on how to reduce electricity use at home with little effort or discomfort.

Wind erosion and associated dust emissions play a fundamental role in many ecological processes, yet most ecological studies do not explicitly consider dust-driven processes despite the growing body of evidence suggesting that wind erosion is a key driver of land surface dynamics and many other environmentally relevant processes such as desertification. This study provides explicit support for a pervasive underlying but untested desertification hypothesis by showing that at the vegetation patch scale shrubs are significantly more efficient at capturing wind-blown sediment and other resources such as nutrients than grasses and that this difference is amplified following disturbance. At the landscape scale, the spacing and shape of woody plants were found to be a major determinant of dryland aeolian sediment transport processes in grasslands, shrublands, woodlands and forests, particularly following disturbance. This study also found that disturbance such as fire can have a significant influence on background dust emissions, which can have important consequences for many basic ecological and hydrological processes. Potential interactions between aeolian and fluvial processes were also evaluated in this study, and a new conceptual framework was developed that highlights important differences and similarities between the two processes as a function of scale-dependencies, mean annual precipitation, and disturbance. This study also explicitly evaluates the effect of climatic extremes and alternate land management practices on the absolute and relative magnitudes of wind and water erosion. Notably, results indicate that wet/dry climatic extremes and grazing can increase the wind-to-water erosion ratio, whereas burning disproportionally increases water erosion relative to wind erosion.

Marine phytoplankton is responsible for ~50% of global primary productivity, it supports the oceanic food web and affects biogeochemical cycles. I participated in a large mesocosm experiment that observed altered community structure and carbon drawdown in response to increased CO2. There was a 27% reduction in community primary production at the peak of an Emiliania huxleyi-dominated bloom in mesocosms initially at 760 ppm CO2 compared to present day pCO2. There were changes in community structure but not dominance; Synechococcus and large pico-eukaryote abundances were reduced by ~60%, E. huxleyi was reduced by ~50%. A number of E. huxleyi strains persisted throughout the experiment in both treatments and no malformation or significant change in lith size occurred at increased CO2. In a second field experiment in the oligotrophic ocean off the Canary Islands, 760 ppm pCO2 did not change community structure or cell division rates of Synechococcus, Prochlorococcus or pico-eukaryotes.In laboratory experiments, I maintained the diatom, Thalassiosira pseudonana CCMP1335 at 760 ppm and present day pCO2 for ~100 generations in gas equilibrated continuous cultures – one of the longest experiments that has been attempted to investigate the effect of increased CO2 on marine phytoplankton. No clear evidence of adaptation or acclimation to increased CO2 was found, neither were there consistent changes in transcription of RuBisCO or carbonic anhydrase genes. Non-calcified E. huxleyi CCMP1516 and calcified CCMP371 grown in gas equilibrated semi-continuous cultures for several weeks showed no change in cell division rate at 760 ppm CO2. An understanding of the underlying changes in communities is required for modelling responses to increasing CO2, molecular tools may prove useful for this task. The strong community response in the mesocosms shows that rising atmospheric CO2 can greatly affect phytoplankton productivity and biogeochemical cycling.

Public awareness of environmental problems and the need to work towards their solution have been heightened at international conferences for over two decades.Knowledge of the range of environmental perspectives and attitudes, and understanding the reasons for them, are important requirements for decision-making when dealing with global environmental issues. It is argued that culture may impact on environmental views and attitudes may shape worldwide views that give rise to them.In this study, Australian, Maldivian and Indonesian trainee teacher communities served as sources of data to examine the influence of culture on environmental attitudes. The three communities examined viewed the term 'environment' differently, and that was one reason for different environmental attitudes being exhibited.It was also found that knowledge about environments was obtained from different sources, and some individuals and communities exhibited both pro-New Environmental Paradigm and pro-Human Exemptionalist Paradigm views simultaneously. This is inconsistent with a western view of environmentalism. The findings have implications for environmental education curricula and the negotiation of global environmental issues. / Doctor of Philosophy (PhD)

This dissertation explores the sustainability of the pugkêenga system of household cooperation as practiced by Mossi rural producers on the Central Plateau of Burkina Faso. Consistent with the sustainable livelihoods framework, this dissertation systematically compares the assets of two different types of domestic organization found among Mossi domestic groups today: extended and nuclear households. Similar studies in contemporary West Africa and other parts of the world suggest that globalization and modernization make extended forms of household organization unsustainable and impractical in the face of changing ecologies and the penetration of capitalist modes of production. This study challenges such assertions and contends that the material and moral configurations of extended households actually enhances their sustainability in the face of environmental and social change. The Sahel region, in which the fieldwork took place, has undergone a period of prolonged desiccation. The Central Plateau is also one of the most densely populated areas within the Sahel. These factors contribute to the high rate of migration for which the Mossi and Central Plateau are well-known. This research investigates these dynamics with ethnographic fieldwork, statistical analyses, and agent based modeling. The results of these analyses demonstrate that the pugkêenga system of household cooperation enhances the household livelihood sustainability under increased climate variability, population pressure, and migration.

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Since the end of the Cold War, conflict prevention and resolution, peacekeeping and peacebuilding have risen to the top of the international agenda. The third edition of this hugely popular text explains the key concepts, charts the development of the field, evaluates successes and failures, and assesses the main current challenges and debates in the second decade of the twenty¿first century. Existing material has been thoroughly updated and four new chapters added, on environmental conflict resolution, conflict resolution in the arts and popular culture, conflict resolution in the media and the communications revolution, and theories and critiques of the field. The authors argue that a new form of cosmopolitan conflict resolution is emerging, which offers a hopeful means for human societies to handle their conflicts non¿violently and eventually to transcend and celebrate their differences. Part I offers a comprehensive survey of the theory and practice of conflict resolution. Part II sets the field within the context of rapid global change and addresses the controversies that have surrounded conflict resolution as it has entered the mainstream. Contemporary Conflict Resolution is essential reading for students of peace and security studies, conflict management and international politics, as well as for those working in non¿governmental organizations and think-tanks.

With the introduction of metacommunity theory, the field of community ecology expanded its scope to include patterns and processes beyond the scale of local communities. Dispersal, or the movement of organisms between sites, can play an influential role in generating patterns of community assembly and stability. However, little is known about the role of dispersal in structuring and stabilizing freshwater communities. For my dissertation, I conducted a literature review of dispersal in stream metapopulations and metacommunities. Our current knowledge of the movement of freshwater taxa is limited due to difficulties in accurately monitoring dispersal. We have inferred the role of dispersal based primarily on organismal-based and graph-based proxies, although the body of work in modeling and experimental research is growing. Future research should incorporate innovative methods to directly monitor dispersal at finer spatial and temporal scales. To address this knowledge gap, we experimentally manipulated dispersal mode (aerial and drift) alongside the magnitude of dispersal (network location as a proxy) to investigate the role of these components of dispersal in community assembly and multiple metrics of stability. The results of my experiment suggest both factors may play a role in community assembly and stability patterns in stream metacommunities. Lastly, I conducted a mesocosm experiment with zooplankton mesocosms to investigate if biodiversity can generate asynchronous patterns of community dynamics that contribute to stability. There was a positive biodiversity-asynchrony relationship that, in turn, generated higher levels of stability. This effect was strongest in communities connected via dispersal. Overall, my dissertation demonstrates that dispersal plays a role in the assembly and stability of freshwater communities. / Doctor of Philosophy / Freshwater ecosystems and the abundance and richness of life that they support are threatened under global environmental change. One factor that may help maintain the diversity of stream-dwelling species is dispersal, or the movement of organisms between sites within networks of freshwater communities. The influence of dispersal on the formation and stability of freshwater communities is poorly understood. To determine the state of the science, I conducted a literature review on the study of dispersal in stream networks. We have only recently developed a limited knowledge of the direct movement of freshwater species within networks. The majority of what we know is deduced from patterns of diversity, the traits of organisms, or theoretical modeling. More direct measures of dispersal are needed to understand the dispersal of freshwater organisms. To address this knowledge gap, I conducted an experiment with streamside flumes throughout a stream network where I manipulated how a macroinvertebrate could colonize, or join, a stream community. I found that both position in a network and the use of various methods of colonization affect patterns of diversity and how stable stream communities are. Finally, I conducted an experiment where I manipulated the number of zooplankton and environmental conditions to detect the influence of dispersal on community dynamics and stability. Communities connected via dispersal had the highest level of asynchrony in dynamics and these community dynamics, in turn, produced the greatest amount of community stability. Overall, these findings demonstrate the role of dispersal in the biodiversity and stability of freshwater communities.