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Full-Text Articles in Physical Sciences and Mathematics
Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner
Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner
Electronic Theses and Dissertations
In boreal regions, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however less is known about the extent and implications of these events on lakes. We assessed the effects of precipitation events on six drinking water lakes in Maine, USA to better understand how DOC concentration and quality change in response to precipitation events. Our results revealed three types of responses: (1) an initial spike in DOC concentrations and quality metrics; (2) a sustained increase in DOC concentrations and quality metrics and; (3) no change during all sampling periods. Lake residence time was a …
Ammonium Cycling And Nitrifier Community Composition In Eutrophic Waters Affected By Cyanobacterial Harmful Algal Blooms, Justyna J. Hampel
Ammonium Cycling And Nitrifier Community Composition In Eutrophic Waters Affected By Cyanobacterial Harmful Algal Blooms, Justyna J. Hampel
Browse all Theses and Dissertations
Non-point source nitrogen (N) from agriculture is a main driver of eutrophication in aquatic systems, which often manifests as toxin producing cyanobacterial harmful algal blooms (cyanoHABs). Non-N2 fixing cyanobacteria, such as Microcystis, thrive on chemically reduced N forms (e.g., ammonium (NH4+) and urea) used as the main N form in fertilizer. NH4+ turnover rates are important components of the aquatic N cycle in eutrophic lakes affected by cyanoHABs. Regeneration of NH4+ can contribute to the internal cycling of NH4+, which can sustain cyanoHABs when external loads are low. Additionally, NH4+ uptake by cyanobacteria competes directly with nitrification, another important pathway …
Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White
Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White
Theses and Dissertations (Comprehensive)
Arctic and subarctic environments are being adversely influenced by human-caused climate change across our entire planet. Canada’s northern freshwater ecosystems are influenced by a variety of environmental stressors and are particularly sensitive to climate change, since small shifts in climate have the potential to substantially alter their hydrological, limnological, and biogeochemical conditions. Some other indirect effects on northern freshwater landscapes are the expansion of vegetation as well as changes in wildlife and waterfowl populations and distribution. It is, therefore, critical to understand the observed and predicted influences of climate change and other environmental stressors on these northern freshwater environments dominant …