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Full-Text Articles in Life Sciences
Spatial Heterogeneity Of Nitrogen Cycling Within And Across Freshwater Ecosystems, Erin K. Eberhard
Spatial Heterogeneity Of Nitrogen Cycling Within And Across Freshwater Ecosystems, Erin K. Eberhard
Dissertations, Master's Theses and Master's Reports
Dinitrogen (N2) fixation and denitrification are two nitrogen (N) cycling processes that despite differences in environmental requirements and constraints, co-occur in aquatic ecosystems. The overall goal of this dissertation was to evaluate how spatial heterogeneity of environmental variables 1) drive hot spots of N2 fixation, denitrification rates and gene abundances in streams, 2) facilitate co-occurrence of these processes across wetland – stream – lake interfaces, and 3) affect differences in microbial community composition in streams across U.S. ecoregions. We found hot spots of both processes within 7 stream reaches in Michigan and Idaho, but rates of N …
Denitrification And Nitrogen Fixation Commonly Co-Occur But Rates Vary Throughout The Year And In Different Environments, Kevin Nevorski
Denitrification And Nitrogen Fixation Commonly Co-Occur But Rates Vary Throughout The Year And In Different Environments, Kevin Nevorski
Dissertations, Master's Theses and Master's Reports
Denitrification and nitrogen fixation are nitrogen cycling processes that can occur simultaneously in streams but are rarely studied together. The overarching goal of this dissertation was to quantify temporal and spatial variation of these processes in streams across the USA, characterize the environmental drivers of that variation, and determine the role that denitrification plays in the carbon cycle. To characterize temporal variation in these processes, a 2-year study in the Pilgrim River in Michigan’s Upper Peninsula found no difference in rates among seasons but high day-to-day variation in rates of both processes (maximum daily change 4,390 μg N/m2/hr …