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dc.contributor.advisorBurgin, Amy J
dc.contributor.authorKelly, Michelle Catherine
dc.date.accessioned2020-03-28T21:21:29Z
dc.date.available2020-03-28T21:21:29Z
dc.date.issued2019-05-31
dc.date.submitted2019
dc.identifier.otherhttp://dissertations.umi.com/ku:16545
dc.identifier.urihttp://hdl.handle.net/1808/30207
dc.description.abstractOur current understanding of the relationship between nitrate (NO3-) uptake and energy cycling in rivers is primarily built on studies conducted in low-nutrient (NO3- < 1 mg-N L-1), small (discharge < 1 m3 s-1) systems. Recent advances in sensor technology have allowed for continuous measures of whole-river NO3- uptake, allowing us to address how the relationship between nutrient uptake and metabolism changes over time and space during a nutrient addition in a large river. We treated a six-month controlled nitrogen (N) waste release into the Kansas River (conducted by the City of Lawrence, KS) as an ecosystem-scale nutrient addition experiment. We deployed four NO3- and dissolved oxygen sensor arrays along a 33 km study reach from February to May 2018 to continuously monitor diel NO3--N and stream metabolism. We then evaluated NO3- uptake using the extrapolated diel method and modeled stream metabolism using the single station method. We found the highest uptake rates closest to the nutrient release point (866 g-N m-2 d1), despite high NO3- supply (4.36 mg-N L-1). Net ecosystem productivity was increasingly autotrophic with distance from the release, with the highest respiration rates observed closest to the release point (7.09 g-O2 m-2 d1). However, uptake was decoupled from metabolism metrics, likely due to fine-scale hydrologic and biotic factors. Overall, our work sheds light on the ability of large rivers to retain and transform nutrients, while demonstrating that the fine-scale mechanisms that regulate nutrient retention in large rivers are still largely unknown.
dc.format.extent36 pages
dc.language.isoen
dc.publisherUniversity of Kansas
dc.rightsCopyright held by the author.
dc.subjectBiogeochemistry
dc.subjectEcology
dc.subjectLimnology
dc.subjectDisturbance
dc.subjectEcosystem respiration
dc.subjectNutrient cycling
dc.subjectPrimary production
dc.subjectSensors
dc.titleHigh supply, high demand: A unique nutrient addition decouples nitrate uptake and metabolism in a large river
dc.typeThesis
dc.contributor.cmtememberHusic, Admin
dc.contributor.cmtememberSikes, Benjamin A
dc.thesis.degreeDisciplineEcology & Evolutionary Biology
dc.thesis.degreeLevelM.A.
dc.identifier.orcidhttps://orcid.org/0000-0003-0123-2527


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