Lignin phenols used to infer organic matter sources to Sepetiba Bay – RJ, Brasil
Lignin phenols used to infer organic matter sources to Sepetiba Bay – RJ, Brasil
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DOI：
10.1016/j.ecss.2010.02.008
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发表时间：
2010-04
影响因子：
2.8
通讯作者：
C. Rezende;W. Pfeiffer;L. Martinelli;Elizabeth Tsamakis;J. Hedges;R. Keil
中科院分区：
文献类型：
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作者：
C. Rezende;W. Pfeiffer;L. Martinelli;Elizabeth Tsamakis;J. Hedges;R. Keil
在巴西里约热内卢的Sepitiba湾的沉积物中以及在该湾的四个主要河流输入的推移质沉积物和悬浮沉积物中测量了木质素酚; São弗朗西斯科和Guandu通道以及Guarda和Cação河。河流悬浮木质素产量（3.5-14.6mgC10gdw−1）在雨季和旱季之间变化很小，与河流叶绿素浓度（0.8-50.2μgCL−1）相关性很差。尽管目前的土地利用实践，有利于草地农业或工业用途，河流木质素成分占主导地位的降解叶源材料。例外的是瓜尔达河，它有轻微的影响，从草。木质素酚植被指数，再加上酸/醛和3.5Db/V的比率，表明降解叶衍生的酚类也是主要保存在海湾的木质素成分。边缘香蒲属和米草属的存在。草床周围的海湾部分没有反映在木质素签名。相反，进入海湾的木质素似乎反映了土壤的侵蚀，土壤中含有来自曾经主导分水岭的前大西洋雨林的退化签名，而不是含有来自当前农业用途的显著签名。使用LPVI、原子N：C比和稳定碳同位素（范围在-26.8 ‰和-21.8‰之间）的三组分混合模型支持以下假设：流入海湾的河流输入主要是木质素（占输入的78%），木质素主要是叶（占输入的14%），而不是草（6%）。沉积物由大约50-50的本地物质和陆源物质的混合物组成，其中木质素主要来自叶子。
Lignin phenols were measured in the sediments of Sepitiba Bay, Rio de Janeiro, Brazil and in bedload sediments and suspended sediments of the four major fluvial inputs to the bay; São Francisco and Guandu Channels and the Guarda and Cação Rivers. Fluvial suspended lignin yields (Σ8 3.5–14.6mgC10gdw−1) vary little between the wet and dry seasons and are poorly correlated with fluvial chlorophyll concentrations (0.8–50.2μgCL−1). Despite current land use practices that favor grassland agriculture or industrial uses, fluvial lignin compositions are dominated by a degraded leaf-sourced material. The exception is the Guarda River, which has a slight influence from grasses. The Lignin Phenol Vegetation Index, coupled with acid/aldehyde and 3.5Db/V ratios, indicate that degraded leaf-derived phenols are also the primary preserved lignin component in the bay. The presence of fringe Typha sp. and Spartina sp. grass beds surrounding portions of the Bay are not reflected in the lignin signature. Instead, lignin entering the bay appears to reflect the erosion of soils containing a degraded signature from the former Atlantic rain forest that once dominated the watershed, instead of containing a significant signature derived from current agricultural uses. A three-component mixing model using the LPVI, atomic N:C ratios, and stable carbon isotopes (which range between –26.8 and –21.8‰) supports the hypothesis that fluvial inputs to the bay are dominated by planktonic matter (78% of the input), with lignin dominated by leaf (14% of the input) over grass (6%). Sediments are composed of a roughly 50–50 mixture of autochthonous material and terrigenous material, with lignin being primarily sourced from leaf.