Bouillon Steven, Moens Tom, Koedam Nico, Dahdouh-Guebas Farid, Baeyens Willy, Dehairs Frank
Department of Analytical and Environmental Chemistry, Mangrove Management Group, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
FEMS Microbiol Ecol. 2004 Aug 1;49(2):171-9. doi: 10.1016/j.femsec.2004.03.004.
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 delta13C analysis on sediment cores from various mangrove sites with delta13C data of bacteria-specific phospholipid fatty acids (PLFA) in order to identify the dominant carbon substrates used by in situ bacterial communities. delta13C values of each of these markers showed a range of 10% or more across the different sites and sampling depths, but generally followed the delta13C trend observed in bulk organic carbon. Several sediment cores show a strong vertical gradient in PLFA delta13C, 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.
红树林沉积物中的有机碳来源于本地来源（红树林、微型底栖植物）和潮汐输入（如浮游植物、海草衍生物质）。这些来源的相对输入量在不同红树林地点内部和之间可能有很大差异。我们将来自不同红树林地点的沉积物岩芯的元素（总有机碳/总氮）和整体δ13C分析与细菌特异性磷脂脂肪酸（PLFA）的δ13C数据相结合，以确定原位细菌群落使用的主要碳底物。这些标记物中每一个的δ13C值在不同地点和采样深度范围内显示出10%或更多的变化，但总体上遵循在整体有机碳中观察到的δ13C趋势。几个沉积物岩芯显示出PLFA δ13C的强烈垂直梯度，表明表层对藻类衍生碳有选择性。我们的数据表明，细菌碳底物的来源在不同红树林地点之间差异很大，这意味着在没有估计各种来源的贡献的情况下，关于有机物质矿化的数据不能直接纳入生态系统碳预算。
