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| Titel |
C : N : P stoichiometry at the Bermuda Atlantic Time-series Study station in the North Atlantic Ocean |
| VerfasserIn |
A. Singh, S. E. Baer, U. Riebesell, A. C. Martiny, M. W. Lomas |
| 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 ; 12, no. 21 ; Nr. 12, no. 21 (2015-11-09), S.6389-6403 |
| Datensatznummer |
250118157
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| Publikation (Nr.) |
 copernicus.org/bg-12-6389-2015.pdf |
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| Zusammenfassung |
| Nitrogen (N) and phosphorus (P)
availability, in addition to other macro- and micronutrients, determine the
strength of the ocean's carbon (C) uptake, and variation in the N : P ratio
of inorganic nutrient pools is key to phytoplankton growth. A similarity
between C : N : P ratios in the plankton biomass and deep-water nutrients
was observed by Alfred C. Redfield around 80 years ago and suggested that
biological processes in the surface ocean controlled deep-ocean chemistry.
Recent studies have emphasized the role of inorganic N : P ratios in
governing biogeochemical processes, particularly the C : N : P ratio in
suspended particulate organic matter (POM), with somewhat less attention
given to exported POM and dissolved organic matter (DOM). Herein, we extend
the discussion on ecosystem C : N : P stoichiometry but also examine
temporal variation in stoichiometric relationships. We have analyzed
elemental stoichiometry in the suspended POM and total (POM + DOM) organic-matter (TOM) pools in the upper 100 m and in the exported POM and
subeuphotic zone (100–500 m) inorganic nutrient pools from the monthly
data collected at the Bermuda Atlantic Time-series Study (BATS) site located
in the western part of the North Atlantic Ocean. C : N and N : P ratios
in TOM were at least twice those in the POM, while C : P ratios were up
to 5 times higher in TOM compared to those in the POM. Observed C : N
ratios in suspended POM were approximately equal to the canonical Redfield ratio (C : N : P = 106 : 16 : 1), while N : P and C : P
ratios in the same pool were more than twice the Redfield ratio. Average
N : P ratios in the subsurface inorganic nutrient pool were ~ 26 : 1,
squarely between the suspended POM ratio and the Redfield ratio. We have
further linked variation in elemental stoichiometry to that of
phytoplankton cell abundance observed at the BATS site. Findings from this
study suggest that elemental ratios vary with depth in the euphotic zone,
mainly due to different growth rates of cyanobacterial cells. We have also
examined the role of the Arctic Oscillation on temporal patterns in C : N : P
stoichiometry. This study strengthens our understanding of the variability in elemental stoichiometry in different organic-matter pools and should improve
biogeochemical models by constraining the range of non-Redfield stoichiometry
and the net relative flow of elements between pools. |
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