摘要：Dissolved organic matter (DOM), a heterogeneous mixture of diverse compounds with different molecular weights, is crucial for the lake carbon cycle. The properties and concentration of DOM in lakes are closely related to anthropogenic activities, terrigenous input, and phytoplankton growth. Thus, the lake's trophic state, along with the above factors, has an important effect on DOM. We determined the DOM sources and molecular composition in six lakes along a trophic gradient during and after phytoplankton bloom by combining optical techniques and the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). CDOM pools in eutrophic lakes may be more biologically refractory than in oligotrophic and mesotrophic lakes. Molecular formulas of DOM were positively correlated with the TSI (trophic state index) value (R-2 = 0.73), with the nitrogen-containing compounds (CHON) being the most abundant formulas in all studied lakes. Eutrophication modified the molecular formulas of DOM to have less CHO% and more heteroatom S-containing compounds (CHOS% and CHNOS%), and this was the synactic result of the anthropogenic perturbation and phytoplankton proliferation. In eutrophic lakes, summer DOM showed higher molecular lability than in autumn, which was related to the seasonal phytoplankton community succession. Although the phytoplankton-derived DOM is highly bioavailable, we detected a simpler and more fragile phytoplankton community ecosystem in autumn, which may be accompanied by a lower phytoplankton production and metabolic activity. Therefore, we concluded that the lake eutrophication increased the allochthonous DOM accumulation along with sewage and nutrient input, and subsequently increased its release with phytoplankton bloom. Eutrophication and phytoplankton growth are accompanied by more highly unsaturated compounds, O3S+O5S compounds, and carboxylic-rich alicyclic compounds (CRAMs), which are the biotransformation product of phytoplankton-derived DOM. Eutrophication may be a potential source of refractory DOM compounds for biodegradation and photodegradation. Our results can clarify the potential role of water organic matter in the future global carbon cycle processes, considering the increasing worldwide eutrophication of inland waters.

关键字：Dissolved organic matter; Eutrophication; Trophic state; Phytoplankton; Lakes; Fourier transform ion cyclotron resonance mass; spectrometry

ISSN号：0043-1354

卷、期、页：卷: 224

发表日期：2022-10-01

影响因子：11.236000

期刊分区（SCI为中科院分区）：一区

收录情况：SCIE（科学引文索引网络版）

发表期刊名称：WATER RESEARCH

参与作者：温志丹,尚盈鑫,宋开山,刘阁,侯俊彬,吕丽丽,陶慧,李思佳,何丁

第一作者：何晨,史权

论文类型：期刊论文

论文概要：温志丹,尚盈鑫,宋开山,刘阁,侯俊彬,吕丽丽,陶慧,李思佳,何晨,史权,何丁，Composition of dissolved organic matter (DOM) in lakes responds to the trophic state and phytoplankton community succession，WATER RESEARCH，2022，卷: 224

论文题目：Composition of dissolved organic matter (DOM) in lakes responds to the trophic state and phytoplankton community succession