河口区DOM生物可利用性的时空演变及其调控机制

项目名称： 河口区DOM生物可利用性的时空演变及其调控机制

项目编号： No.41276064

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 郭卫东

作者单位： 厦门大学

项目金额： 82万元

中文摘要： 溶解态有机物（DOM）的生物可利用性是全球碳循环研究的关键科学问题之一。在河口临界带，由于DOM来源多样，各种界面过程复杂，陆-海相互作用中从源到汇的DOM 生物可利用性的时空演变及其关键控制过程尚不清晰。本研究选取暴雨频发、与流域高度耦合的九龙江河口为研究对象，综合运用光谱学及稳定同位素、色谱分析等多种表征手段，研究输入到该河口区的陆地河流、大气干湿沉降、地下水及自生源DOM的化学特征和生物可利用性，探讨来源和化学组成差异对DOM生物可利用性影响的化学机理，估算各种来源的DOM通量及其中活泼与惰性组分的相对贡献，并对比常态和暴风雨条件下流域-河口-近海系统DOM化学组成与生物可利用性的变化。通过上述研究，为评价外部自然及人为扰动对陆源DOM 生物可利用性的影响提供科学依据，揭示河口与近海的微生物对DOM 的利用与转化，评估陆源DOM 入海后的环境生态效应及其长期储存潜力。

中文关键词： 溶解有机物；生物可利用性；河口；光谱分析；碳循环

英文摘要： The biolability of dissolved organic matter (DOM) is a key scientific issue in global carbon cycle. In the estuarine critical zone, the spatial and temporal variations of the biolability of DOM and their major biogeochemical controlling factors are still unclear. This is due to the quite different properties of multiple allochthonous and autochthonous sources of DOM discharging into this dynamic system, and the complex biogeochemical processes between river-sea, sea-atmosphere interfaces and the submarine groundwater-seawater reaction zone. The Jiulong River Estuary is a suitable place for studying such issues as it is highly coupled with its watershed and is also strongly influenced by rainstorm events. In this project, the chemical properties and the biolability of DOM from different sources (terrestrial river discharge, atmospheric deposition, submarine groundwater discharge and in situ biological production) into this estuary will be characterized comprehensively by spectroscopy, stable isotopic analysis and chromatography. The effect of differences in sources and chemical compositions on the lability of DOM will be analyzed and the fluxes of DOC, labile DOC (LDOC) and refractory DOC (RDOC) into the estuary will be estimated based on long-term monitoring data. The DOM properties and its biolability between n

英文关键词： Biobility；DOM；estuary；spectral analysis；Carbon cycle