| 典型水库型湖泊中CDOM吸收及荧光光谱变化特征:基于沿岸生态系统分析 |
| 摘要点击 2691 全文点击 1044 投稿时间：2016-05-08 修订日期：2016-06-03 |
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| 中文关键词 溶解性有机质 长寿湖 紫外-可见光谱 三维荧光光谱 生态系统 三峡库区 |
| 英文关键词 dissolved organic matter Changshou Lake UV-Vis spectroscopy three-dimensional fluorescence spectroscopy ecosystem Three Gorges Reservoir area |
| 作者 | 单位 | E-mail | | 陈雪霜 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | 401602312@qq.com | | 江韬 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå
SE-90183, Sweden | Jiangtower666@163.com | | 卢松 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 白薇扬 | 重庆理工大学化学化工学院, 重庆 400054 | | | 张成 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 王定勇 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 魏世强 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | |
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| 中文摘要 |
| 为进一步了解水库型湖泊溶解性有机质（DOM）的地球化学特征，本文以三峡库区典型内陆水库型湖泊——长寿湖为研究对象，利用紫外-可见和三维荧光光谱，并结合湖区周边生态系统分析，讨论了长寿湖水体中CDOM的组成、来源和空间分布特征.结果表明，长寿湖不同采样点DOM浓度（DOC和CDOM）存在一定程度的空间分布差异，但各点FDOM分布较为稳定.回水区出现DOM累积，由于受陆源输入影响有限，水体内源活动主导，具有较明显"内源控制"特征，芳香性和分子量相对较低；而周边陆地以人工林兼旅游开发为主的采样点，陆源输入在带入较多腐殖化（高芳香性）组分的同时，人为活动排放也是导致其类蛋白组分丰富的重要原因；入湖区尽管周边果林和居民生活对水体DOM有一定影响，但上游河流输入的影响也不容忽视.另外，各采样点也出现了不受周边生态系统影响的独立的相关性特征，例如芳香性特征常数（SUVA280）和光谱斜率[S（275~295）]显著负相关、CDOM和FDOM极显著正相关、CDOM和S（275~295）负相关等.同时，长寿湖水体中CDOM的生色团主要由具有芳香性结构的大分子组分构成；至少51%的CDOM波动可以通过FDOM变化来进行解释，其中回水区荧光组分对CDOM变动的影响最为明显.在采用传统FI值无法区分DOM来源差异性时，结合采样点沿岸生态系统，综合紫外-可见和荧光光谱特征，有助于对DOM组成及来源进行解析. |
| 英文摘要 |
| For further understanding the geochemical characteristics of dissolved organic matter (DOM) in "reservoir-type" lake, in this study a typical "reservoir-type" lake, Changshou Lake located in inlands of Three Gorges Reservoir areas, was selected to investigate the composition, sources and spatial distributions of chromophoric DOM (CDOM) in this lake, through UV-Vis and three-dimensional fluorescence spectroscopy combined within analysis of riparian eco-system differences. The results showed that DOM concentrations including dissolved organic carbon (DOC) and CDOM abundance in different sampling sites varied spatially to a certain degree, in contrast to fluorescence component of DOM showing a constant level. In backwater zone (also called stagnant zone alternatively), due to accumulation of DOM and limited impact of terrestrial contribution, the endogenesis (autochthonous production) was the predominant geochemical process showing an obvious "authigenic-control" characteristic, and relatively lower aromaticity and molecular weight. In comparison, sampling sites surrounding artificial forests and tourism development, the highly humic (highly aromatic) substances resulted from terrestrial inputs were the main source, but discharge due to human activities was also responsible for highly protein-like component observed in DOM. Additionally, in the entry zones of lake from upstream river, DOM was affected by fruit plantations and residences, contribution from upstream river could also be neglected. From the other aspects, some significant correlations were also observed, which were independent of riparian eco-system differences, for example, the SUVA280 versus S(275-295) (negative), CDOM versus FDOM (positive), and CDOM and S(275-295) (negative), indicating the correlation was an intrinsic property of DOM that could not be affected by the surrounding environment. Meanwhile, the main chromophoric component of CDOM in Changshou Lake was high molecular weight (HMW) components within highly aromatic structures. At least, 51% of CDOM dynamic could be explained by changes of FDOM, especially in backwater zone the co-variance was more obvious. Furthermore, when the traditional fluorescence index (FI) could not comprehensively explain the differences of DOM sources due to very similar (statistically insignificant) values, integration of UV-Vis and fluorescence spectral characteristics and detailed discussion of riparian eco-system differences, might be an important way to help further resolution of DOM composition and sources in aquatic environments, such as lake, river and watershed. |
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