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 337 for “"biota"”.
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Effect of heavy metals on salt march biota
Environmental restoration of disturbed, degraded and potentially contaminated wetland sites aims for the persistent and sustainable re-establishment of biological communities and important wetland functions. An ecologically informed restoration strategy presupposes some understanding of these …
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Microplastics chemical characterization, regional distribution, and effects on biota
This dissertation provides an in-depth analysis of the environmental effects of microplastics, with a focus on nurdles (pre-production microplastics) and microfibers . The opening section provides an overview of the pervasive nature of microplastic, and the current methodology used to describe its …
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Shellfish utilization and its effect on rocky shore biota in Transkei
The shellfish on the rocky shores along the Transkei coast experience intense exploitation from three different sources viz. commercial exploitation, tourist - induced exploitation and continued regular harvesting by the indigenous people. The question raised as a result of these combined factors …
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Impacts of biota on bioretention cell function during establishment in the Midwest
To understand the region-specific effects of biota on function of bioretention cells, a lysimeter study was conducted at Kansas State University to determine how earthworms and native Kansas grasses impact runoff treatment and hydraulic function of a bioretention cell. This study also employed the …
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Relation of Missouri river flows to sandbar morphology with implications for selected biota
… highly productive habitats for riverine biota. Sandbars are an important interface between aquatic and terrestrial environments, i.e. an aquatic-terrestrial zone (ATTZ), within the main channel of the lower Missouri River. Predictive models of sandbar morphometry (area, wetted perimeter, …
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El rol de la biota en los procesos de estabilización-desestabilización de sedimentos estuariales
… se determinó cual es el rol de la densidad de la biota en los procesos de erosión y depositación. Para cumplir con el objetivo de este capítulo se realizó un experimento de mesocosmos. Como conclusiones generales resaltan la determinación del efecto desestabilizador de L. culveri, afectando la …
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Bottom-up effects of aboveground biota, invasive species and drought on soil animal communities
… disrupt the regulating interactions between soil biota components, and the role these components play in maintaining the stability of terrestrial ecosystems. <br/><br/>This thesis investigates the response of soil animal communities to disturbances, focusing on perturbations originating …
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Paleoecology of a late quaternary biota at the McClusky Canal Site, central North Dakota
<p>Abundant and well-preserved Late Quaternary fossils were exposed at the McClusky Canal Site in the Missouri Coteau district of central North Dakota during the late summer and fall of 1976. Strati graphic units, in ascending order, are: (l) pebbly, clayey sand; (2) unlaminated, organic claystone; …
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Cliff ecology: Extent, biota, and recreation of cliff environments in the New River Gorge, WV
The New River Gorge National River (NERI) contains an extensive network of exposed cliff-forming sandstone units, the most extensive in West Virginia and possibly within the entire Appalachian range. These cliff resources are critical to NERI's national significance, and contain specialized and …
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Evaluating non-point source microplastic pollution and its impact on biota in the Huron River
… anti-inflammatory drugs (NSAIDs), into biota. The goal of this study was to evaluate 1) the importance of non-point sources of microplastic pollution to the Huron River, 2) if aquatic filter feeders ingest microplastics, and 3) how the interaction of microplastics and pharmaceuticals …
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Estimating Embeddedness From Bankfull Shear Velocity in Gravel Streambeds to Assess Sediment Impacts on Aquatic Biota
… of embeddedness as a habitat metric for lotic biota. The areas that were studied included Stroubles Creek at the Virginia Tech Stream Lab, the Upper Roanoke River Basin in southwest Virginia, and Level II and III ecoregions nationwide with the U.S. EPA National Rivers and Streams Assessment …
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The influence of elevated arsenic concnetrations on stream biota and leaf breakdown in a headwater stream
… occurring element, which is toxic to aquatic biota especially in disturbed areas where it may be found at high concentrations. A headwater stream adjacent to an 85 year-old abandoned arsenic mine was investigated to determine the influence of arsenic on stream biota and processes using an …
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Spatial Patterns of Mercury in Atmospheric Deposition, Soils and Lake Biota in the Adirondack Park, New York
… of Hg in the terrestrial and especially aquatic biota. It is important to understand the mechanisms that contribute to the sensitivity of this region to Hg inputs. In my research, studies of the spatial patterns of Hg in atmospheric deposition, soils and lake biota were conducted as tools to …
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Environmental risk management of contamination of marine biota by hydrocarbons specifically those arising following an oil spill.
Marine pollution resulting from oil spillage has received much attention mostly due to the damaging effects it has on fisheries and aquacultures. One component of oil that is widely studied due to its toxic and carcinogenic properties is the polycyclic aromatic hydrocarbons. The physical and …
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Using polyethylene passive sampling to assess transport of polychlorinated biphenyls (PCBs) between contaminated sediments, water, and biota
Polychlorinated biphenyls (PCBs), which were a widely used group of chemicals before their manufacture was banned in 1979 in the United States, still contaminate numerous aquatic systems. Although there are ongoing efforts to remediate these sites, our ability to implement effective remediation …
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Prototype dynamic tool for the assessment of radiological exposure to non-human biota in a coastal heath dune ecosystem
… here for simulating radionuclide turnover by biota can reproduce realistic trends of 137Cs in a semi-natural environment. The model includes the capability of calculating the dose to vegetation from externally deposited radionuclides. This is a novel calculation that allows a more complete …
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Predicting the Repercussions of Anthropogenic Landscape Modifications on the Biota Using Species Focused Adaptable GIS and Spatial Dynamic Models
Habitat fragmentation and species invasions are increasingly threatening the survival of native species worldwide. In this context, a set of tools and approaches was developed to help (1) improve our understanding of species relationships to the landscape and predict their habitat usage, population …
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Impacts of Delayed Drawdown on Water Quality and Aquatic Biota in Seasonal Wetlands of the Grassland Ecological Area, Los Banos, California
The 178,000-acre Grassland Ecological Area in California’s San Joaquin Valley is managed to provide overwintering habitat to waterfowl on the Pacific Flyway. The major management activity is the fall flooding and spring drawdown of wetlands, timed to optimize the availability of forage vegetation …
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Alternative approaches for monitoring aquatic ecosystems: a study on the effects of municipal sewage effluent on biota in the South Saskatchewan River
… municipal sewage effluent were conducted on biota from the South Saskatchewan River through field monitoring and artificial stream experimentation. Field studies indicated that primary productivity was stimulated by nutrient enrichment, however, standing crop measurements were strongly …
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The ecological effects of bioturbation on the eelgras Zostera capensis : community interactions and the impacts on the biota of an intertidal sandflat
… the sedentary mudprawn Upogebia africana and the biota of an intertidal sandflat were assessed at Langebaan Lagoon, South Africa, through comparative surveys, observations and field experiments. I hypothesised that C. kraussi and Z. capensis have mutually detrimental effects on each other, with …
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