Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"Ecosystem Impacts"”.
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Dispersal and remineralisation of biodeposits: Ecosystem impacts of mussel aquaculture
… the benthic-pelagic coupling of nearshore ecosystems. In New Zealand the mussel Perna canaliculus has a high natural abundance and is also intensively cultured. This thesis examines the dispersal and remineralisation characteristics of mussel P. canaliculus biodeposits and the impacts of …
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Economic and Ecosystem Impacts of GM Maize in South Africa
<p>White maize in South Africa is the only staple crop produced on a widespread commercial basis for direct human consumption using genetically modified (GM) cultivars. Using a combined economic and environmental approach, we estimate the total welfare benefits attributable to GM white maize in …
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Anticipation, significance and response to ecosystem impacts of large dams
… of the key issues responsible for significant ecosystem impacts and highlights key responses practices in a variety of different regions and countries world-wide.
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Surface and Subsurface Application of Chemical Dispersants and Associated Ecosystem Impacts
… <p><strong> </strong>While the efficacy, ecosystem impacts, and ultimate fate of chemical dispersants and dispersed oil generates conflicting opinions in the scientific community, there are measures that could be taken in order to minimize potential impacts. Research that accounts for …
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Ecosystem impacts of the invasive rusty crayfish (Faxonius rusticus) over time
… of the ecological hierarchy, from genes to ecosystems, with negative consequences for biodiversity and global economies. These impacts likely vary over time and with invasion stage, though long-term studies on the effects of invasive species are rare. In my thesis, I use a unique long-term …
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Ecosystem impacts of intertidal invertebrate harvesting: from benthic habitats to bird predators.
… achieve sustainability and to maintain healthy ecosystem functioning. This thesis investigates impacts of intertidal harvesting on benthic habitats and invertebrate communities as well as the potential impacts of harvesting on shorebird populations. Implications for management of inshore and …
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Mitigation of water quality and ecosystem impacts of roadway construction through retrospective engineering analyses
During the construction of a segment of Appalachian Corridor H between Buckhannon and Elkins, West Virginia, mine spoils and land use features related to historic mining were disturbed. An assessment of the water quality, benthic macro invertebrates, and fish populations was conducted to ascertain …
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Ecosystem impacts of variable recruitment in Antarctic krill investigated with long-term monitoring and archived ADCP backscatter data
<p>In this work, I explore the impacts of anthropogenic climate change on the krill-reliant marine ecosystem of the western Antarctic Peninsula. I use long-term ecological monitoring data to examine the impact of highly variable krill recruitment on a krill predator population, and I use archived …
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Use of Stable Isotopes to Trace the Fate of Applied Nitrogen in Forest Plantations to Evaluate Fertilizer Efficiency and Ecosystem Impacts
… N cycling and partitioning in a loblolly pine ecosystem (see Chapter 4). Chapter 2 results showed enhanced efficiency fertilizers (EEFs) significantly reduced ammonia (NH3) volatilization losses compared to urea. Mean NH3 volatilization after spring fertilization ranged from 4% to 26% for EEFs …
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Ecosystem impacts of tamarisk (Tamarix spp.) management in the Arkansas River watershed, Colorado: effects of disturbance and herbicide residues on passive plant community restoration
… field experiments that determined the ecological impacts of currently used tamarisk control strategies, with a particular emphasis on the effects of herbicide residues on plant community restoration patterns following management. First, an in vitro study and high-performance liquid chromatography …
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Building voluntary sustainability : how urban design can promote care for ecological systems
… in aggregate present state, unsustainable by the ecosystem of the earth. This thesis develops a behavior change model of how societies can move from unsustainable to sustainable behavior, and, because behavior is in large part a result of personal conviction, the factors that result in voluntary …
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Los nuevos medios y el periodismo de medios sociales: Análisis y aplicación de las redes sociales en los medios digitales españoles
… results of the questionnaire. The new digital ecosystem impacts with virulence in the practice of Journalism , as well as it has been tested in the context of the last two years. A stage in which there has been a strong emergence of social networks . Consequently, this research seeks to answer …
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Modelling the two-phase plume dynamics of CO2 leakage into open shallow waters
… study to predict the near field physicochemical impacts and biological risk to the marine ecosystem from CO2 leakage from potential carbon storage locations around the North Sea. New sub-models are developed for bubble formation and drag coefficients using in-situ measurements from videos of the …
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The effects of fire and drought on plant-soil feedbacks of a nonnative invasive grass in southern Illinois
Non-native plants can disrupt ecosystem functioning and internally reinforce their dominance over native species by altering soil nutrient availability (i.e. resource-mediated feedbacks) and by modifying fire regimes (i.e. disturbance-mediated feedbacks). While fire and other disturbances are shown …
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Social Marginal Abatement Cost of Negative Emissions : Incorporating Externalities into the Private Costs of Carbon Dioxide Removal
… a comprehensive life-cycle analysis, including impacts on human health and ecosystems, were monetized to establish external costs for each NETP. These external costs were subsequently incorporated with private costs, gathered from existing literature. The final step involved combining these …
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Evaluating Chemical Toxicity: A Novel Behavioral Assay Using Daphnia
… crustaceans (0.5-5.0mm) in freshwater ecosystems. They are commonly used for aquatic toxicity testing because of high sensitivity to changes in their environment. This novel optical bioassay was validated with a series of model compounds that have known modes of action. By measuring …
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A systems approach to assessing the sustainability of hybrid community energy systems.
… on time, space, and receptor (i.e., human or ecosystem impacts) criteria. Aggregation yields an ISI between zero and one, where one represents a sustainable system. The ISI is calculated for several different case studies spanning a range of fossil- and renewable-based energy systems. Each is …
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Leaf Traits, Neighbors, and Abiotic Factors: Ways That Context Can Mediate the Impact of Invasive Species on Nitrogen Cycling
… of a species can dramatically change critical ecosystem processes, factors that mediate the direction and magnitude of those impacts have received less attention. A better understanding of the factors that mediate invasion impacts on ecosystem functioning is needed in order to target which …
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Investigating the distribution of Nitellopsis obtusa in Ontario Lakes and its role as an ecosystem engineer
… since the 1970s, little is known about the ecosystem- and community-level impacts upon establishment. My thesis aimed to elucidate these potential effects by focusing on both within-lake and regional scale N. obtusa populations. I conducted a comprehensive investigation into ecosystem …
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A Study on Photodegradation and The Fate of Pyrogenic Carbon
… in aquatic systems is crucial to understanding ecosystem impacts and potential feedback to climate change. Current research indicates that despite a generally lower susceptibility to biodegradation than their unpyrolyzed equivalents, pyrogenic carbon is not environmentally inert. While the role …
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