Leopold A. auteur aut IRD Marchand Cyril auteur aut IRD Deborde J. auteur aut IRD Allenbach M. auteur aut IRD text journalArticle eng text/pdf born digital access Carbon budgets in mangrove forests are uncertain mainly due to the lack of data concerning carbon export in dissolved and gaseous forms. Temporal variability of in situ CO2 fluxes was investigated at the sediment-air interface in different seasons in different mangrove stands in a semi-arid climate. Fluxes were measured using dynamic closed incubation chambers (transparent and opaque) connected to an infra-red gas analyzer. Microdimatic conditions and chl-a contents of surface sediments were determined. Over all mangrove stands, CO2 fluxes on intact sediments were relatively low, ranging from -3.93 to 835 mmolCO(2).m(-2).h(-1) in the light and in the dark, respectively. Changes in the fluxes over time appeared to depend to a great extent on the development of the biofilm at the sediment surface. We suggest that in intact sediments and in the dark, CO2 fluxes measured at the sediment-air interface rather reflect the metabolism of benthic organisms than sediment respiration (heterotrophic and autotrophic). However, without the biofilm, sediment water content and air temperature were main drivers of seasonal differences in CO2 fluxes, and their influence differed depending on the intertidal location of the stand. After removal of the biofilm, Q(10) values in the Avicennia and the Rhizophora stands were 1.84 and 2.1, respectively, revealing the sensitivity of mangrove sediments to an increase in temperature. This study provides evidence that, if the influence of the biofilm is not taken into account, the in situ CO2 emission data currently used to calculate the budget will lead to underestimation of CO (2) production linked to heterotrophic respiration fueled by organic matter detritus from the mangrove. specialized In situ sediment CO2 fluxes Seasonal variation Biofilm Mangrove New Caledonia NOUVELLE CALEDONIE 082 036 502 617-626 2015 0048-9697 https://www.documentation.ird.fr/hor/fdi:010063124 10.1016/j.scitotenv.2014.09.066 0048-9697 [F B010063124] https://www.documentation.ird.fr/hor/fdi:010063124 https://www.documentation.ird.fr/intranet/publi/2015/01/010063124.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-02-02 2017-08-23 fdi:010063124 fre