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| Titel |
Modeling plankton ecosystem functioning and nitrogen fluxes in the oligotrophic waters of the Beaufort Sea, Arctic Ocean: a focus on light-driven processes |
| VerfasserIn |
V. Fouest, B. Zakardjian, H. Xie, P. Raimbault, F. Joux, M. Babin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 7 ; Nr. 10, no. 7 (2013-07-15), S.4785-4800 |
| Datensatznummer |
250018344
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| Publikation (Nr.) |
 copernicus.org/bg-10-4785-2013.pdf |
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| Zusammenfassung |
| The Arctic Ocean (AO) undergoes profound changes of its physical and biotic
environments due to climate change. In some areas of the Beaufort Sea, the
stronger haline stratification observed in summer alters the plankton
ecosystem structure, functioning and productivity, promoting oligotrophy. A
one-dimension (1-D) physical–biological coupled model based on the large
multiparametric database of the Malina project in the Beaufort Sea was used
(i) to infer the plankton ecosystem functioning and related nitrogen fluxes
and (ii) to assess the model sensitivity to key light-driven processes
involved in nutrient recycling and phytoplankton growth. The coupled model
suggested that ammonium photochemically produced from photosensitive
dissolved organic nitrogen (i.e., photoammonification process) was a
necessary nitrogen source to achieve the observed levels of microbial
biomass and production. Photoammonification directly and indirectly (by
stimulating the microbial food web activity) contributed to 70% and
18.5% of the 0–10 m and whole water column, respectively, simulated
primary production (respectively 66% and 16% for the bacterial
production). The model also suggested that variable carbon to chlorophyll
ratios were required to simulate the observed herbivorous versus microbial
food web competition and realistic nitrogen fluxes in the Beaufort Sea
oligotrophic waters. In face of accelerating Arctic warming, more attention
should be paid in the future to the mechanistic processes involved in food
webs and functional group competition, nutrient recycling and primary
production in poorly productive waters of the AO, as they are expected to
expand rapidly. |
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