| 摘要: |
| 为了解红树林与光滩磷、铁地球化学行为的差异，借助薄膜扩散梯度技术（ZrO-Chelex DGT），对厦门同安湾红树林及临近光滩孔隙水中溶解活性磷（DRP）、Fe2+浓度进行了原位测量，并采集了相应沉积物柱状样进行理化参数的测定分析。结果表明：（1）Fe2+与DRP呈现较好的线性正相关，说明磷的吸附/解吸与铁氧化还原循环有关；（2）在不同深度，光滩孔隙水中DRP浓度均高于对应深度红树林。在浅层，由于溪水的补给造成光滩的磷富集；在深层，红树植物根部吸收导致磷浓度下降，光滩有机质含量较多，矿化释放DRP使其浓度较高；（3）孔隙水中的Fe2+浓度分布表明，红树林区域随着深度的增加，逐渐由好氧环境进入厌氧环境；而光滩沉积物氧化还原环境可能受到红树林的影响，孔隙水Fe2+在垂向上波动分布。 |
| 关键词: 磷、铁分布特征 DGT取样技术 泥质潮滩 红树林 孔隙水 |
| DOI： |
| 分类号: |
| 基金项目: |
|
| The Difference of Dissolved Reactive Phosphorus and Ferrous Iron distribution in porewater between mangrove wetland and bare mudflat in Tongan Bay |
|
CAI Yu,GUO Zhan-rong,PAN Feng,LIU Hua-tai,WANG Bo,LI Zhi-wei,ZHUANG Zhen-jie
|
|
1.College of Ocean and Earth Sciences,Xiamen University;2.College of The Environment and Ecology,Xiamen University
|
| Abstract: |
| To better understand the geochemical behavior of phosphorus and iron in mangrove wetland and bare mudflat, we conducted a in situ measurement of phosphorus and iron in porewater in Tongan Bay, Xiamen, using The technique of Diffusive Gradients in Thin films (DGT). For measuring the content of TOC, salinity, Total iron and particle size, we sampled the sediment beside DGT device. The result demonstrates that:(1)The positive correlation between dissolved reactive phosphorus(DRP) and ferrous iron(Fe2+) concentration verified the key role of iron-redox cycling in controlling DRP variation..(2)The concentration of DRP in bare mudflat is higher than mangrove wetland, which could attributed to river contamination, mangrove plant adsorption and decomposition of Organic Matter(OM) .(3)The distribution of Fe2+ concentration in mangrove pore water indicate that the oxic condition in shallow wetland converted into anoxic zone with depth increasing, the variation of Fe2+ imply that the OM flushed from mangrove affecting redox environment in bare mudflat nearby and thus influence iron-redox cycling. |
| Key words: Distribution of phosphorus and iron Diffusive Gradients in Thin film technique(DGT) Tidal mudflat mangrove Pore water |