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| Titel |
A 13C labelling study on carbon fluxes in Arctic plankton communities under elevated CO2 levels |
| VerfasserIn |
A. Kluijver, K. Soetaert, J. Czerny, K. G. Schulz, T. Boxhammer, U. Riebesell, J. J. Middelburg |
| 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. 3 ; Nr. 10, no. 3 (2013-03-01), S.1425-1440 |
| Datensatznummer |
250018133
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| Publikation (Nr.) |
 copernicus.org/bg-10-1425-2013.pdf |
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| Zusammenfassung |
| The effect of CO2 on carbon fluxes (production, consumption, and export)
in Arctic plankton communities was investigated during the 2010 EPOCA (European project on Ocean Acidification)
mesocosm study off Ny Ålesund, Svalbard. 13C labelled bicarbonate
was added to nine mesocosms with a range in pCO2 (185 to
1420 μatm) to follow the transfer of carbon from dissolved
inorganic carbon (DIC) into phytoplankton, bacterial and zooplankton
consumers, and export. A nutrient–phytoplankton–zooplankton–detritus model
amended with 13C dynamics was constructed and fitted to the data to
quantify uptake rates and carbon fluxes in the plankton community. The
plankton community structure was characteristic for a post-bloom situation
and retention food web and showed high bacterial production (∼31%
of primary production), high abundance of mixotrophic phytoplankton, low
mesozooplankton grazing (∼6% of primary production) and low
export (∼7% of primary production). Zooplankton grazing and
export of detritus were sensitive to CO2: grazing decreased and export
increased with increasing pCO2. Nutrient addition halfway through the
experiment increased the export, but not the production rates. Although
mixotrophs showed initially higher production rates with increasing CO2,
the overall production of POC (particulate organic carbon) after nutrient addition decreased with
increasing CO2. Interestingly, and contrary to the low nutrient
situation, much more material settled down in the sediment traps at low
CO2. The observed CO2 related effects potentially alter future
organic carbon flows and export, with possible consequences for the
efficiency of the biological pump. |
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