%0 Journal Article %T 太湖梅梁湾藻华暴发消退-周期表层水体溶解性有机质分子特征 %T Molecular characteristics of surface dissolved organic matter in Meiliang Bay of Lake Taihu over the algal blooming-disappearance cycle %A 庞佳丽,许燕红,何毓新,史权,何丁,孙永革 %A PANG,Jiali %A XU,Yanhong %A HE,Yuxin %A SHI,Quan %A HE,Ding %A SUN,Yongge %J 湖泊科学 %J Journal of Lake Sciences %@ 1003-5427 %V 32 %N 6 %D 2020 %P 1599-1609 %K 富营养化;太湖;梅梁湾;溶解性有机质;分子组成;傅立叶变换离子回旋共振质谱;碳循环 %K Eutrophication;Lake Taihu;Meiliang Bay;dissolved organic matter (DOM);molecular characterization;FT-ICR MS;carbon cycle %X 人类活动引起的富营养化对太湖的碳循环模式可能产生严重影响,精细描述太湖藻华暴发-消退周期的溶解性有机质分子是了解太湖碳库动态变化的关键.本研究利用傅立叶变换离子回旋共振质谱技术,以太湖北部梅梁湾2017年5月至2018年5月的表层水体为研究对象,解析藻华暴发-消退周期溶解性有机质的来源和分子组成特征,进而理解浮游藻类异常增殖对水体溶解性有机质的影响及其在区域碳循环中的角色.研究结果表明,藻华暴发期浮游藻类生产力显著增加,使得表层水体的溶解性有机质从含量到分子组成均发生剧烈改变.含量上表现为溶解性有机碳浓度升高,分子组成上表现为CHO类化合物和以脂肪族类化合物为代表的活性组分占比增加,特征化合物以相对高饱和度和高含氧的小质量数分子为主.而在藻华消退期,随着藻类有机质贡献的减少和有机质降解过程的持续进行,含量上表现为溶解性有机碳浓度下降,分子组成上表现为CHOS、CHONS类化合物和富羧酸脂环类化合物等惰性分子占比增加,特征化合物以大质量数分子和相对低饱和度和低含氧的小质量数分子为主.研究结果表明,太湖水体的溶解性有机质分子组成在藻华暴发期受藻类有机质输入控制,在消退期受藻类有机质降解的影响. %X Eutrophication induced by human activities may has a critical impact on the carbon cycle of Lake Taihu. Assisted by the technique of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), we investigated the molecular characteristics of dissolved organic matter in Meiliang Bay of Lake Taihu over the algal blooming-disappearance cycle at 2017-2018 to better understand the influence of algae blooming to the dissolved organic matter pool. The results show that during the algal-blooming period, the massively increasing productivity from algae have changed the amount and the molecular characteristics of dissolved organic matter in water from Lake Taihu. Basically, the concentration of dissolved organic carbon as well as the proportion of the relatively labile components (CHO-compounds, aliphatic compounds, and low-molecular-mass compounds with higher H/C and O/C values) increased during the algal-blooming period. While in the algal-disappearance period, due to both the low input of algal biomass and the continuous degradative progress of dissolved organic matter in the water column, the concentration of dissolved organic carbon decreased. Synchronously, the proportion of the relatively refractory components (CHOS-compounds, CHONS-compounds, CRAM compounds, high-molecular-mass compounds, and low-molecular-mass compounds with lower H/C and O/C values) increased. The dynamics of the molecular characteristics of dissolved organic matter in Meiliang Bay of Lake Taihu indeed propose the critical impact of eutrophication on the regional carbon cycle, asking for further research. %R 10.18307/2020.0603 %U http://www.jlakes.org/ch/reader/view_abstract.aspx %1 JIS Version 3.0.0