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High supply, high demand: A unique nutrient addition decouples nitrate uptake and metabolism in a large river
dc.contributor.advisor | Burgin, Amy J | |
dc.contributor.author | Kelly, Michelle Catherine | |
dc.date.accessioned | 2020-03-28T21:21:29Z | |
dc.date.available | 2020-03-28T21:21:29Z | |
dc.date.issued | 2019-05-31 | |
dc.date.submitted | 2019 | |
dc.identifier.other | http://dissertations.umi.com/ku:16545 | |
dc.identifier.uri | http://hdl.handle.net/1808/30207 | |
dc.description.abstract | Our 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.extent | 36 pages | |
dc.language.iso | en | |
dc.publisher | University of Kansas | |
dc.rights | Copyright held by the author. | |
dc.subject | Biogeochemistry | |
dc.subject | Ecology | |
dc.subject | Limnology | |
dc.subject | Disturbance | |
dc.subject | Ecosystem respiration | |
dc.subject | Nutrient cycling | |
dc.subject | Primary production | |
dc.subject | Sensors | |
dc.title | High supply, high demand: A unique nutrient addition decouples nitrate uptake and metabolism in a large river | |
dc.type | Thesis | |
dc.contributor.cmtemember | Husic, Admin | |
dc.contributor.cmtemember | Sikes, Benjamin A | |
dc.thesis.degreeDiscipline | Ecology & Evolutionary Biology | |
dc.thesis.degreeLevel | M.A. | |
dc.identifier.orcid | https://orcid.org/0000-0003-0123-2527 | |
dc.rights.accessrights | openAccess |