Data/hora: 01/06/2024 09:53:57

Provedor de dados: | 5
País: | France

Título:

Rôle de l’apport atmosphérique sur les processus de biodégradation et la stoechiométrie de la matière organique dissoute en mer Méditerranée

Role of atmospheric deposition on biodegradation processes and stoichiometry of dissolved organic matter in the Mediterranean sea

Autores: | Djaoudi, Kahina.
Data: | 2018-03-09
Ano: | 2018
Palavras-chave: | Dépôt atmosphérique; Matière organique dissoute; Rapports C:N:P; Nutriments; Mer Méditerranée; Biodisponibilité.; Atmospheric deposition; Dissolved organic matter; C:N:P ratios; Nutrients; Mediterranean Sea; Bioavailability.
Resumo: | Establishing a link between atmospheric deposition and the dissolved organic matter (DOM) pool in the Mediterranean Sea is currently hampered by: (1) a poor knowledge on the surface dissolved phosphate (P) pool, mainly due to low concentrations of dissolved inorganic phosphate (DIP), (2) a critical lack of data on atmospheric fluxes of organic C, N and P and (3) the lack of information on their bioavailability. This PhD thesis aimed at filling these gaps. (1) Relying upon a sensitive determination of DIP, the coverage of the valid dissolved organic phosphate data was enhanced up to 70%, revealing a vertical pattern in the dissolved phosphate biogeochemistry in surface waters. (2) Atmospheric fluxes of soluble organic C, N and P were quantified and were 59 mmol C m-2 yr-1, 16.4 mmol N m-2 yr-1 and 23.6 μmol P m-2 yr-1, respectively. The contribution of the organic fraction to the total atmospheric fluxes of N and P was of 40% and 25%, respectively. The labile fraction of atmospheric deposition of organic phosphate was also quantified during the study period and showed a wide variability, ranging from 0 to 97%. (3) The bioavailability of atmospheric organic matter was experimentally assessed. DOM contained in a Saharan rainwater could support the activity of marine heterotrophic bacteria, with an amount of labile carbon of 29%. The labile fraction of carbon contained in desert dust and anthropogenic aerosols was also substantial, 26 ± 2% and 15 ± 5%, respectively. The results obtained from this PhD thesis emphasize the non-negligible character of atmospheric deposition and highlight the key role that this external source could have on the oceanic DOM cycle.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00677/78944/81332.pdf

https://archimer.ifremer.fr/doc/00677/78944/

Editor: | Université Aix Marseille
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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