Intense nitrogen cycling in permeable intertidal sediment revealed by a nitrous oxide hot spot
| Autor: | Alicia M. Wilson, Samantha B. Joye, Charles A. Schutte, Willard S. Moore, Karen L. Casciotti, Tyler B. Evans |
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| Rok vydání: | 2015 |
| Předmět: |
Atmospheric Science
Global and Planetary Change Denitrification chemistry.chemical_element Nitrous oxide Nitrogen Human impact on the nitrogen cycle Trace gas chemistry.chemical_compound chemistry Nitrate Environmental chemistry Environmental Chemistry Environmental science Eutrophication Nitrogen cycle General Environmental Science |
| Zdroj: | Global Biogeochemical Cycles. 29:1584-1598 |
| ISSN: | 1944-9224 0886-6236 |
| DOI: | 10.1002/2014gb005052 |
| Popis: | Approximately 40% of the total global rate of nitrogen fixation is the result of human activities, and most of this anthropogenic nitrogen is used to fertilize agricultural fields. Approximately 23% of the applied agricultural nitrogen is delivered to the coastal zone, often reducing water quality and driving eutrophication. Nitrogen cycling in coastal sediments can mitigate eutrophication by removing bioavailable nitrogen. However, some of these processes generate nitrous oxide, a potent greenhouse gas, as a by-product. Here we report the discovery of a nitrous oxide production hot spot in shallow barrier island sands. Nitrous oxide concentrations, production and consumption rates, vertical diffusion fluxes, and flux to the atmosphere were measured across triplicate depth profiles. Using a mass balance approach, rates of net nitrous oxide production were estimated to be 40 µmol m−2 d−1. This production was driven by a hot spot of nitrate consumption that removed bioavailable nitrogen from the coastal environment at a rate of 10 mmol m−2 d−1, a rate that is comparable with the highest rates of denitrification reported for coastal sediments. |
| Databáze: | OpenAIRE |
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