大型丝状绿藻生长过程中有色溶解有机质光谱特征的变化

通过室外模拟实验研究崇明岛北湖滩涂大型丝状绿藻常见种-刚毛藻在生长过程中有色溶解有机质(CDOM)的光谱特征变化。利用三维荧光光谱(EEMS)检出的类蛋白和类腐殖酸荧光峰在对照实验中变化不大，而在培养实验中明显增加。采用平行因子模型(PARAFAC)结合三维荧光激发-发射矩阵数据分析得到的CDOM的4个组分: C₁, C₂, C₃, C₄，分别与类腐殖酸荧光峰A(C)，M和类蛋白荧光峰B和T有关。培养实验中，4组分分别增加了211.5%，255.8%，75.3%和129.3%;对照实验中除C₁降低34.3%外，其他组分无明显变化。吸收系数a(355)在培养实验中增加了92.9%，并且与4组分显著正相关(P<0.01);对照实验中a(355)降低了59.8%，仅与C₁显著相关(P<0.05)。此外对表征分子量和组成的M值和S值进行比较发现，培养实验中M值和S值均低于对照实验。这说明在刚毛藻生长过程中可能有大分子和较强芳香性的CDOM产生。所有结果表明，刚毛藻的生长过程能够引起CDOM含量和组成结构的变化。

Spectral Characteristics Variations of Chromophoric Dissolved Organic Matter During Growth of Filamentous Green Macroalgae

As an important component of dissolved organic matter (DOM), chromophoric dissolved organic matter (CDOM) plays a central role in the global biogeochemical carbon cycle. Macroalgae are essential producers in aquatic ecosystems. They can release a considerable part of photosynthetic products as CDOM. So changes in optical properties of CDOM are studied on filamentous green macroalgae-Chadophorasle found in tidal flats of a brackish Lake Beihu in natural field condition by using spectrometry. Humic-like fluorescence peaks and protein-like fluorescence peaks detected by fluorescence excitation-emission matrix spectrum (EEMS) change little in control experiment but increase dramatically in incubation experiment. Applying parallel factor analysis (PARAFAC) together with fluorescence excitation-emission matrix can get four components of CDOM (C₁, C₂, C₃ and C₄) which are relative to humic-like fluorescence peak A(C), M and protein-like fluorescence peak B, T respectively. In incubation experiment four components increase by 211.5%, 255.8%, 75.3% and 129.3% respectively while in control experiment components have little changes except C₁ decreasing by 34.3%. Absorption coefficient a(355) increases by 92.9% and has positive significant correlation(P<0.01) with the four components in incubation experiment while a(355) decreases by 59.8% and only has correlation (P<0.05) with C₁ in control experiment. As the parameters representing CDOM molecular weight and composition, M and S values in incubation experiment are smaller than in control experiment, which illustrate that aromatic and macromolecular CDOM is produced in growth of Chadophorasle. All results indicate that growth of Chadophorasle can change the content and composition of CDOM.