Concentrations and Fractionation of Carbon, Iron, Sulfur, Nitrogen and Phosphorus in Mangrove Sediments Along an Intertidal Gradient (Semi-Arid Climate, New Caledonia)

Journal of Marine Science and Engineering

Jonathan Deborde²  Cyril Marchand²  Nathalie Molnar²  Luc Della Patrona¹  Tarik Meziane⁴  Joseph M. Smoak³ 

[1] Département Lagons, Ecosystèmes et Aquaculture Durable (LEAD/NC), Ifremer, 101, Promenade Roger Laroque, Center IRD, BP 2059–98846 Nouméa Cedex, Nouvelle-Calédonie; E-Mail:;Institut de Recherche pour le Développement (IRD), UR 206, UMR 7590—IMPMC, F-98848 New Caledonia, France; E-Mails:Institut de Recherche pour le Développement (IRD), UR 206, UMR 7590—IMPMC, F-98848 New Caledonia, France;;UMR BOREA 7208 CNRS-MNHN-UPMC-IRD-UCBN, Muséum National Histoire Naturelle, CP 53, 61 rue Buffon, 75231 Paris cedex 05, France; E-Mail:

关键词: mangrove;    zonation;    biogeochemistry;    New Caledonia;   

DOI  :  10.3390/jmse3010052

来源: mdpi

【 摘 要 】

In mangrove ecosystems, strong reciprocal interactions exist between plant and substrate. Under semi-arid climate, Rhizophora spp. are usually predominant, colonizing the seashore, and Avicennia marina develops at the edge of salt-flats, which is the highest zone in the intertidal range. Along this zonation, distribution and speciation of C, Fe, S, N, and P in sediments and pore-waters were investigated. From the land-side to the sea-side of the mangrove, sediments were characterized by I/ increase in: (i) water content; (ii) TOC; (iii) mangrove-derived OM; II/ and decrease in: (i) salinity; (ii) redox; (iii) pH; (iv) solid Fe and solid P. Beneath Avicennia and Rhizophora, TS accumulated at depth, probably as a result of reduction of iron oxides and sulfate. The loss of total Fe observed towards the sea-side may be related to sulfur oxidation and to more intense tidal flushing of dissolved components. Except the organic forms, dissolved N and P concentrations were very low beneath Avicennia and Rhizophora stands, probably as a result of their uptake by the root systems. However, in the unvegetated salt-flat, NH₄⁺ can accumulate in organic rich and anoxic layers. This study shows: (i) the evolution of mangrove sediment biogeochemistry along the intertidal zone as a result of the different duration of tidal inundation and organic enrichment; and (ii) the strong links between the distribution and speciation of the different elements.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.