Data/hora: 06/06/2024 01:04:37

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	NH4+ turnover in intertidal sediments of Marennes-Oleron Bay (France): effect of sediment temperature	
Autores: 	Vouve, Florence; Guiraud, Gérard; Marol, Christine; Girard, Marine; Richard, Pierre; Laima, Mario.	
Data: 	2000-09	
Ano: 	2000	
Palavras-chave: 	N 15; Intertidal sediments; Sediment temperature; NH4+ turnover; 15N; Sédiments intertidaux; Température du sédiment; Régénération du NH4 +.	
Resumo: 	NH4+ turnover plays an important role in benthic compartment as source of nutrient for primary production. The intertidal mudflats of the Marennes-Oleron Bay are characterized by high fluctuations of sediment temperature that generally ranges from 10 to 30 degreesC during emersion periods. Influence of sediment temperature on NH4+ processes was investigated. Grass ammonification and NH4+ incorporation kinetics were studied using the N-15 isotope dilution method. The method was first adapted to these very fine sediments and applied to 2 upper sediment layers (0-2 and 2-4 cm) at different incubation times of up to 120 h. The effect of sediment temperature on gross ammonification and NH4+ incorporation rates was investigated at 10, 20 and 30 degreesC. There was a strong increase of both rates as a function of temperature, gross ammonification rates ranged from 0 to 17 mug NH4+-N.g(-1) dw.d(-1) and NH4+ incorporation rates from 2 to 13 mug N.g(-1) dw.d(-1) between 10 and 30 degreesC. This study showed that short-term temperature variations during the emersion period should be taken into account in quantifying NH4+ turnover in intertidal sediments and that benthic regeneration of NH4+ significantly supports benthic and planktonic primary production in Marennes-Oleron Bay. It suggests also that there is no N-limitation for benthic primary production in this bay and that there is up to 44 % of NH4+ produced in surface sediments, which can diffuse to the water column and become available to phytoplankton.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2000/publication-530.pdf

DOI:10.1016/S0399-1784(00)01104-X	
Editor: 	Elsevier	
Relação: 	http://archimer.ifremer.fr/doc/00000/530/	
Formato: 	application/pdf	
Fonte: 	Oceanologica Acta (0399-1784) (Elsevier), 2000-09 , Vol. 23 , N. 5 , P. 575-584	
Fonte: 	2000 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS