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 66 for “"Nutrient Enrichment"”.
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Denitrification response to nutrient enrichment in New Zealand estuaries
… use intensifies, estuaries receive increased nutrient and sediment loads, resulting in habitats dominated by muddy organic-rich sediments. Nutrient processing and denitrification in estuarine sediments represent important ecosystem functions regenerating nutrients for primary producers, and …
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Consequences of nutrient enrichment for soil organic matter cycling in grasslands
… activities have increased the availability of nutrients, such as nitrogen (N), phosphorus (P), and potassium (K), worldwide. Since alterations to nutrient cycles influence carbon (C) fixation and decomposition processes, nutrient enrichment affects global C stocks -- such as soil C. Carbon in …
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Nutrient enrichment modulates the structure and temporal assembly of riverine benthic algal and macroinvertebrate assemblage.
Nutrient enrichment has become one of the most widespread anthropogenic forces impacting freshwater biodiversity worldwide. Stream communities are frequently limited by nutrient availability, and enrichment over natural concentrations can impact both the distribution of species and the temporal …
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Interaction between grazing by starfish (parvulastra exigua) and nutrient enrichment on intertidal soft-sediment communities.
… Bottom-up control is frequently represented by nutrient level, which determines ecosystem productivity. Top-down control includes consumer (e.g. grazers and predators) effects on lower trophic levels. Consumers determine community structure through 2 main interacting mechanisms viz. by creating …
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Interaction between grazing by starfish (parvulastra exigua) and nutrient enrichment on intertidal soft-sediment communities.
… Bottom-up control is frequently represented by nutrient level, which determines ecosystem productivity. Top-down control includes consumer (e.g. grazers and predators) effects on lower trophic levels. Consumers determine community structure through 2 main interacting mechanisms viz. by creating …
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Augmentation of mass transfer through electrical means and nutrient enrichment for suspension and entrapment cell cultures
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1994.
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The interactive effects of disturbance and nutrient enrichment on species diversity and biomass of intertidal rocky-shore communities
Unimodal patterns of diversity along gradients of both disturbance and productivity rank amongst the most celebrated generalizations in ecology, known as the Intermediate Disturbance Hypothesis (IOH) and Productivity Diversity Hypothesis. However, doubt about their generality has arisen from …
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Evaluating the Potential Impacts of Municipal Wastewater Effluent on Benthic Macroinvertebrates in the Upper Bow River
… systems. MWWE is a complex mixture containing nutrients and many emerging chemicals of concern (ESOCs), which may vary due to treatment type, receiving environments, and the population served. Outputs of MWWE have been associated with nutrient enrichment (eutrophication) but as populations grow …
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Trophic dynamics in Australian seagrass beds : unravelling linkages from nutrients to fish
… disturbance rapidly altering bottom-up (e.g. nutrient enrichment) and top-down (e.g. fisheries exploitation) processes. To enhance understanding of bottom up and top-down influences in productive estuaries, this study investigated a prominent four level food chain (epiphytic algae, …
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Quantifying the Effects of Watershed Size and Land Development on Stream Nutrients
Excessive nutrient loading from watersheds causes nutrient enrichment and water quality issues in very small streams to large rivers. Nutrient enrichment is exacerbated by urbanization and agricultural land use; however, the magnitude of the problem differs by regional landscape and environmental …
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Pushing the boundaries : Virgilia oroboides (Keurboom) facilitated expansion of forest in to fynbos
… has been shown to be primarily a function of nutrients and light environments in the understory which may or may not be conducive for the growth of forest species. Additionally, it is understood that fire regime is the primary agent in determining forest/fynbos boundaries. Virgilia oroboides …
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Effects of Water Column P-availability and Litter Microbial Mediated Processes and Stoichiometry in Aquatic Systems
<p>Anthropogenic nutrient enrichment of aquatic ecosystems is prevalent and can have detrimental effects on biological condition. Many of these effects have been attributed directly or indirectly to changes in autotrophic processes. However, in detrital-based streams changes in course detrital …
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Effects of anthropogenic land use on temperate mangrove forests
… ecosystems that play a crucial role in filtering nutrients, retaining pollutants, and sequestering carbon. However, to what extent they are impacted by an intensification of human pressures is unclear and empirical evidence of landscape scale effects of a holistic view of the ecosystem is scarce. …
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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
Assessments of nutrient enrichment and contaminant toxicity from treated 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 …
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Biogeochemical niche construction in the forest-fynbos mosaic of Jonkershoek Nature Reserve, South Africa
… winter. Soil properties, mainly texture and nutrient concentration differed distinctly between forest and fynbos. I argue that these differences are caused by topographical diversity and maintained by vegetation which influences nutrient enrichment via dust accumulation and plant litter …
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Treatment of clam-processing wastewater using upflow anaerobic sludge blanket (UASB) technology
… 12,500 ppm inhibition was essentially 100%. Nutrient enrichment did not affect methane production.
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The impact of conifer plantation forestry on the ecology of peatland lakes
… substances including hydrogen ions (H+), plants nutrients, dissolved organic carbon (DOC), heavy metals and sediment. The aims of this study were to investigate the effect of conifer plantation forestry on the hydrochemistry and ecology of blanket bog lakes in western Ireland. Lake …
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Detecting anthropogenic impacts on estuarine benthic communities
… diffuse land-derived stressors (sedimentation, nutrient loading, and heavy metal contamination) on estuarine benthic communities. Using Gradient Forest analysis, I explored the relative importance of environmental factors, operating across multiple spatio-temporal scales, in influencing patterns …
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Understanding good ecological status: a palaeolimnological approach
… to reconstruct the long-term (10² to 10³ years) nutrient status of Upper Talley and Llyn Pencarreg, two closely adjacent, moderately nutrient-enriched lakes in Carmarthenshire, South Wales. The use of diatoms, Pediastrum and ephippia allows for the analysis of changes in ecosystem dynamics in …
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Paleolimnology of selected Precambrian Shield lakes /
… with successional changes in the lake's biota. Nutrients released by the deciduous component of the Found Lake watershed appeared to be especially important in determining diatom and Mallomonas standing crop. The top 20 cm of sediment of 3 ,Shield lakes was then investigated using close interval …
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