| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
The effects of nutrient additions on particulate and dissolved primary production and metabolic state in surface waters of three Mediterranean eddies
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| Autores: |
Lagaria, A.
Psarra, S.
Lefevre, D.
Van Wambeke, France
Courties, C.
Pujo-pay, M.
Oriol, L.
Tanaka, T.
Christaki, U.
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| Data: |
2011
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| Ano: |
2011
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| Resumo: |
We examined the effects of nutrient additions on rates of (14)C-based particulate and dissolved primary production as well as O(2)-based metabolic rates in surface waters (8 m) of three anticyclonic eddies, located in the Western, Central and Eastern Mediterranean. Ship-board microcosm experiments employing additions of inorganic nitrogen (+N) and phosphorus (+P), alone and in combination (+NP), were conducted in June/July 2008 during the BOUM (Biogeochemistry from the Oligotrophic to the Ultra-oligotrophic Mediterranean) cruise. In all three experiments, particulate primary production was significantly stimulated by the additions of nitrogen (+N, +NP) while no effect was observed with the addition of phosphorus alone (+P). Percent extracellular release of photosynthate (PER) displayed the lowest values (4-8%) in the +NP treatment. Among the three treatments (+N, +P, +NP), the +NP had the strongest effect on oxygen metabolic rates, leading to positive values of net community production (NCP>0). These changes of NCP were mainly due to enhanced gross primary production (GPP) rather than reduced dark community respiration rates (DCR). In all three sites, in +NP treatment autotrophic production (whether expressed as GPP or PP(total)) was sufficient to fulfil the estimated carbon requirements of heterotrophic prokaryotes, while addition of nitrogen alone (+N) had a weaker effect on GPP, resulting in metabolically balanced systems. At the three sites, in treatments with N (+N, +NP), phytoplankton and heterotrophic prokaryote production were positively correlated. Heterotrophic conditions were observed in the Control and +P treatment at the central and eastern sites, and autotrophic production was not sufficient to supply estimated bacterial carbon demand, evidence of a decoupling of phytoplankton production and consumption by heterotrophic prokaryotes.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/00133/24401/22418.pdf
DOI:10.5194/bg-8-2595-2011
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| Editor: |
Copernicus Gesellschaft Mbh
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| Relação: |
http://archimer.ifremer.fr/doc/00133/24401/
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| Formato: |
application/pdf
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| Fonte: |
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2011 , Vol. 8 , N. 9 , P. 2595-2607
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| Direitos: |
Author(s) 2011. CC Attribution 3.0 License.
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