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.
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Showing 1 to 20 of 51 for “"Ecosystem structure"”.
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Development of Ecosystem Structure and Function on Reforested Surface-Mined Lands
… efforts also restore the native forest ecosystem functions. We quantified rates of return of key ecosystem functions and structural attributes of the post-mining forested ecosystem. A chronosequence of four reforested mine sites and an unmined reference stand were studied in southwestern …
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Effects of physical and chemical disturbance on stream ecosystem structure and function
… and anthropogenic disturbances influence the structure and function of stream ecosystems. While past investigations have focused on the response of community indicators to stream disturbances, functional indicators may also be helpful for assessing stream ecosystem health. To date, few studies …
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Hydrologic Controls on Ecosystem Structure and Function in the Great Dismal Swamp
… motivating recent restoration efforts. Community structure and function were hydrologically altered by 19th and 20th century ditches installed to lower water levels and enable early timber harvesting. Contemporary forest communities are comprised of maturing remnants from selective timber …
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Spatial Drivers of Ecosystem Structure and Function in a Floodplain Riverscape: Springbrook Nutrient Dynamics
… disturbance and succession. I hypothesized that ecosystem processes in spring brooks would differ spatially across biophysical zones because landscape position dictates severity of flood disturbance and allochthonous inputs from contiguous terrestrial and groundwater systems. Between July and …
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Spatial Drivers of Ecosystem Structure and Function in a Floodplain Riverscape: Springbrook Nutrient Dynamics
… disturbance and succession. I hypothesized that ecosystem processes in spring brooks would differ spatially across biophysical zones because landscape position dictates severity of flood disturbance and allochthonous inputs from contiguous terrestrial and groundwater systems. Between July and …
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INFLUENCES OF DISEASE-DRIVEN AMPHIBIAN DECLINES ON ECOSYSTEM STRUCTURE AND FUNCTION IN PANAMANIAN HEADWATER STREAMS
… relationships between biodiversity and ecosystem function is a critical challenge, particularly in freshwater ecosystems where species losses are occurring at unprecedented rates. There is a particular need to examine these relationships in natural settings at large spatial scales. …
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The changing face of Andean peatlands: the effects of climate and human disturbance on ecosystem structure and function
… better understand the northern Andean peatland ecosystems. In conclusion: high elevation peatlands in the Northern Andes are ecosystems that offer extremely important ecological services but that may have started an irreversible decline.
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Remote Sensing Characterization of Ecosystem Structure and Functional Types to Inform on Biodiversity Conservation in the Lowland Chocó Rainforest
… of remote sensing techniques to characterize ecosystem structure and functional types to inform on biodiversity conservation. This work is motivated by a guiding hypothesis that increased degradation of tropical forest biodiversity due to human activity results in in measurable changes in …
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Influence of Multiple Disturbances on Stream Structure and Function
… the influence of multiple disturbances on ecosystem structure and function in a headwater stream adjacent to an abandoned arsenic mine using an upstream (reference) and downstream (mine-influenced) comparative reach approach. In this study, floods were addressed as a pulse disturbance, and …
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Soil-plant-herbivore interactions and nutrient dynamics in semi-arid grazing systems in northeastern Brazil and western USA
… sustainability and control important aspects of ecosystem function. In the series of studies in this dissertation, we evaluate how human-induced disturbances and interactions between soil, plants, and herbivores influence nutrient cycling, productivity, and ecosystem structure in semi-arid …
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Impacts of Land-Use on Leaf Breakdown and Macroinvertebrate Assemblages in Southern Appalachian Streams
… long been associated with alterations in stream ecosystem structure and function, however, 'exurbanization' and its impact on streams is poorly understood. This study compares the ecosystem structure and function of 9 southern Appalachian streams of differing land-use (forested, exurban, …
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Polar Bear (Ursus Maritimus) Foraging Ecology in the Western Canadian Arctic
… bear foraging patterns can provide insights on ecosystem structure and function both spatially and temporally. This thesis used quantitative fatty acid signature analysis (QFASA) to estimate the diets, and adipose tissue lipid content to estimate the body condition, of polar bears in three …
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Ecohydrology and self-organization of black ash wetlands
… these feedbacks with consequent changes to ecosystem state. Imminent and widespread emerald ash borer (EAB) infestation throughout North America has raised concern over possible ecosystem state shifts in forested wetlands (i.e., to wetter, more herbaceous systems) and loss of forest …
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Analyzing longitudinal patterns of river metabolism in five distinct rivers
… common frameworks or theories to describe river ecosystem structure and function. While these concepts help explain how rivers should behave, the reality is that aquatic ecosystems are being changed and degraded due to dams which regulate flow and changes to land use and land cover that can …
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Ecological implications of allelopathic interferences with reference to Phragmites australis
The effects of plant invasions on ecosystem structure and function are well studied but the pathways and mechanisms that underlie these effects remain poorly understood. In depth investigation of invasion mechanisms is vital to understanding why invasive plants impact only certain systems, and why …
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Hydrologic Regime and Soil Property Interactions in a Forested Peatland
… degradation via drainage, with consequences for ecosystem structure and function such as increased fire vulnerability, soil oxidation, and altered vegetation composition. Peatland function is largely dependent on hydrologic regimes and their influences on the accumulation and properties of peat …
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Influence of Agricultural Land Use on Allochthonous Input and Leaf Breakdown in Southern Appalachian Streams
Streams and terrestrial ecosystems are linked through allochthonous organic matter inputs from streamside vegetation. This allochthonous material makes up the energy base for forested aquatic food webs. Therefore, removal of riparian vegetation associated with agricultural land use affects stream …
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A Post-Restoration Assessment of the Fishes and Macroinvertebrates of Mill Branch, Knox County, Kentucky, with Emphasis on the Blackside Dace (Chrosomus cumberlandensis)
… restoration, to evaluate the overall stream ecosystem structure and function of Mill Branch, and to assist in our efforts to successfully enhance other degraded streams. </p>
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Comparison of Quantitative and Semi-Quantitative Assessments of Benthic Macroinvertebrate Community Response to Elevated Salinity in central Appalachian Coalfield Streams
… (SC), can cause adverse effects on aquatic ecosystem structure and function. In central Appalachia, eastern USA, studies largely rely on Rapid Bioassessment Protocols with semi-quantitative sampling to characterize benthic macroinvertebrate community response to increased salinity caused by …
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