浅水湖泊草源型有色可溶有机物（CDOM）的生消过程特征分析

有色可溶有机物（CDOM）是水生生态系统溶解有机碳储库的主要组分，在湖泊生态系统结构、初级生产力以及物质交换等方面都发挥着重要作用。CDOM的来源决定了其具有不同的光学和化学特性，目前对于大型水生植物残体腐解产生CDOM的生消过程并不清楚。本项目拟以浅水湖泊草型湖区大型水生植物为研究对象，通过野外原位观测及室内模拟实验，运用三维荧光光谱、傅里叶变换离子回旋共振质谱等分析技术，联合高通量测序等现代生物学技术，明确浅水湖泊草型区CDOM时空变化特征；研究植物残体不同分解阶段产生CDOM的过程特征，构建CDOM产生的动力学过程，及其与环境因子的关联性；探究影响CDOM消亡的主导途径，以及CDOM消亡对微生物群落的响应，最终揭示草源型CDOM的生消过程特征。本项目为进一步研究湖泊中CDOM的迁移转化及循环机制提供科学的理论指导依据。

Chromophoric Dissolved Organic Matter (CDOM), a main component of dissolved organic carbon sources in aquatic ecosystem, plays an important role in lake ecosystem structure, primary productivity and nutrients exchange. CDOM sources determine its optical and chemical properties. Currently, generation and degradation of CDOM derived from decayed macrophytes are not well understood. This proposal aims to demonstrate temporal and spatial variations in aquatic plants-derived CDOM in grass-type zones in freshwater lakes, to characterize CDOMs in different decomposition phases of aquatic plant residues, to elucidate the dynamics of CDOM production, and to establish the correlation of CDOM with environmental parameters. Additionally, main CDOM mineralization pathway and the corresponding responsive variations in microbial communities will also be investigated. To these ends, field investigations and indoor simulation experiments will be conducted by using, advanced analysis methods including Three-Dimensional Excitation Emission matrix Fluorescence Spectrophotometer (EEMs), Fourier transform ion cyclotron resonance-Mass Spectrometry (FT-ICR-MS) and microbial High-throughput sequencing technology. The expected results will add new insights about the production of plant-derived CDOM, and provide theory basis for further studies of CDOM migration, transformation, and circulation mechanism in lakes.