Publications des scientifiques de l'IRD

Lu Y. Y., Wen Z. Z., Shi D. L., Lin W. F., Bonnet Sophie, Dai M. H., Kao S. J. (2019). Biogeography of N-2 fixation influenced by the western boundary current intrusion in the South China Sea. Journal of Geophysical Research : Oceans, 124 (10), p. 6983-6996. ISSN 2169-9275.

Titre du document
Biogeography of N-2 fixation influenced by the western boundary current intrusion in the South China Sea
Année de publication
2019
Type de document
Article référencé dans le Web of Science WOS:000491809800001
Auteurs
Lu Y. Y., Wen Z. Z., Shi D. L., Lin W. F., Bonnet Sophie, Dai M. H., Kao S. J.
Source
Journal of Geophysical Research : Oceans, 2019, 124 (10), p. 6983-6996 ISSN 2169-9275
The N-2 fixation and primary production rates were measured simultaneously using N-15(2) and C-13 incubation assays in the northern South China Sea influenced by the Kuroshio intrusion (KI) seasonally. The degree of KI (KI index, range from 0 to 1) was assessed by applying an isopycnal mixing model. The water column integrated N-2 fixation and primary production for stations with KI index larger than 0.5 were 463 +/- 260 mu mol N center dot m(-2)center dot day(-1) and 62 +/- 19 mmol C center dot m(-2)center dot day(-1), respectively, significantly higher than those for stations with KI index lower than 0.5 (50 +/- 10 mu mol N center dot m(-2)center dot day(-1) and 28 +/- 10 mmol C center dot m(-2)center dot day(-1), respectively). Trichodesmium was the dominant diazotroph at stations with KI index larger than 0.5, with 2 orders of magnitude higher nifH gene abundance than that at stations with KI index lower than 0.5. However, the highest N-2 fixation rates were found in waters with moderate KI index around 0.6, suggesting that frontal zone mixing might stimulate N-2 fixation. Our results demonstrated that diazotrophs (mainly Trichodesmium) were tightly associated with the KI, which modulated the biogeographic distribution of N-2 fixers. In summary, we found the transportation of Trichodesmium by KI, then, we quantified the fraction of KI and N-2 fixation rates in the northern South China Sea. The results suggested that KI generated a new biogeographic regime which could significantly influence the carbon and nitrogen cycles far away from the main stream.
Plan de classement
Limnologie physique / Océanographie physique [032] ; Limnologie biologique / Océanographie biologique [034]
Description Géographique
MER DE CHINE
Localisation
Fonds IRD [F B010077125]
Identifiant IRD
fdi:010077125
Contact
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    Horizon Pleins textes
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