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Titel |
Distinct bacterial-production–DOC–primary-production relationships and implications for biogenic C cycling in the South China Sea shelf |
VerfasserIn |
C.-C. Lai, Y.-W. Fu, H.-B. Liu, H.-Y. Kuo, K.-W. Wang, C.-H. Lin, J.-H. Tai, G. T. F. Wong, K.-Y. Lee, T.-Y. Chen, Y. Yamamoto, M.-F. Chow, Y. Kobayashi, C.-Y. Ko, F.-K. Shiah |
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 ; 11, no. 1 ; Nr. 11, no. 1 (2014-01-09), S.147-156 |
Datensatznummer |
250117110
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Publikation (Nr.) |
copernicus.org/bg-11-147-2014.pdf |
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Zusammenfassung |
Based on two summer spatio-temporal data sets obtained from the northern
South China Sea shelf and basin, this study reveals contrasting relationships
among bacterial production (BP), dissolved organic (DOC) and primary
production (PP) in the transition zone from the neritic to the oceanic
regions. Inside the mid-shelf (bottom depth <100 m), where inorganic
nutrient supplies from river discharge and internal waves were potentially
abundant, BP, DOC and PP were positively intercorrelated, whereas these
three measurements became uncorrelated in the oligotrophic outer shelf and
slope. We suggest that the availability of limiting minerals could affect the
couplings/decouplings between the source (i.e. phytoplankton) and sink (i.e.
bacteria) of organic carbon, and thus DOC dynamics. DOC turnover times were
homogeneously low (37–60 days) inside the mid-shelf area and then increased
significantly to values >100 days in the outer shelf, indicating that
riverine (Pearl River) DOC might be more labile. The actual mechanism for
this is unknown, but might relate to higher inorganic nutrient supply from
river/terrestrial sources. The positive correlation of the BP / PP ratios
vs. phosphate (and nitrate) concentrations in the inner shelf implies that if
anthropogenic mineral loading keeps increasing in the foreseeable future, the
near-shore zone may become more heterotrophic, rendering the system a stronger
source of CO2. |
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