Variability in the origin of carbon substrates for bacterial communities in mangrove sediments
Bouillon, S.; Moens, T.; Koedam, N.; Dahdouh-Guebas, F.; Baeyens, W.; Dehairs, F. (2004). Variability in the origin of carbon substrates for bacterial communities in mangrove sediments. FEMS Microbiol. Ecol. 49(2): 171-179. dx.doi.org/10.1016/j.femsec.2004.03.004
In: FEMS Microbiology Ecology. Federation of European Microbiological Societies: Amsterdam. ISSN 0168-6496; e-ISSN 1574-6941, more
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| Keywords |
Mineralization
Marine/Coastal |
| Abstract |
Organic carbon in mangrove sediments originates from both local sources (mangroves, microphytobenthos) and tidal inputs (e.g. phytoplankton, seagrass-derived material). The relative inputs of these sources may vary strongly, both within and between different mangrove sites. We combined elemental (TOC/TN) and bulk d13C analysis on sediment cores from various mangrove sites with d13C data of bacteria-specific phospholipid fatty acids (PLFA) in order to identify the dominant carbon substrates used by in situ bacterial communities. ?13C values of each of these markers showed a range of 10‰ or more across the different sites and sampling depths, but generally followed the d13C trend observed in bulk organic carbon. Several sediment cores show a strong vertical gradient in PLFA d13C, suggesting a selectivity for algal-derived carbon in the surface layers. Our data demonstrate that the origin of bacterial carbon substrates varies widely across different mangrove sites, and imply that data on mineralization of organic matter cannot be directly incorporated in ecosystem carbon budgets without an estimation of the contribution of various sources. |
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