作者：Sang, D., Zhang, C., Yao, X., Lü, W., Sun, Z., Wang, S., Zhang, J., Sun, X. & Liu, J.

Dissolved organic matter (DOM), characterized by its high vulnerability to degradation, is integral to riverine ecosystems and has a substantial impact on carbon emissions. However, the impacts of DOM and its degradation on carbon emissions remain unclear. This study employed a combination of meta-analysis, field sampling, and laboratory experiments to examine the effects of DOM concentration, composition, and degradation transformation on carbon emissions. Meta-analysis of literature data revealed that elevated dissolved organic carbon (DOC) concentrations in water bodies significantly increased dissolved CO2 concentrations (cCO2), CO2 diffusion fluxes (FCO2), and dissolved CH4 concentrations (cCH4). Field investigations in the inflow rivers of Lake Taihu, utilizing stable isotope and multi-spectral techniques, demonstrated that protein-like substances dominated the DOM composition, accounting for 74.98 +/- 11.10 % of the overall fluorescence intensity. The delta 13C-CH4 values (-31.18 %o +/- 3.79 %o) indicated that acetoclastic methanogenesis was the dominant pathway. Further analysis suggested that an increase in terrestrial humic-like substances in the study area may promote carbon emissions. The DOM degradation experiment further showed that DOM degradation promoted the production of CH4. The amount of CH4 released through light combined with biodegradation (L-Biodegradation) exceeds that from biodegradation. In addition, the consumption of humic-like substances during DOM degradation is a crucial factor in promoting CH4 production. This research enhances the comprehension of the relationship between DOM degradation and greenhouse gas emissions. Furthermore, it offers potential strategies for the control and mitigation of greenhouse gas emissions from riverine environments.

溶解有机质（DOM）因其易降解特性而成为河流生态系统的核心组分，并对碳排放产生重大影响。然而，DOM及其降解过程对碳排放的影响尚不明确。本研究结合荟萃分析、野外采样与室内实验，系统考察了DOM的浓度、组成及降解转化对碳排放的作用。文献数据的荟萃分析表明，水体中溶解有机碳（DOC）浓度升高会显著增加溶解态CO₂浓度、CO₂扩散通量以及溶解态CH₄浓度。在太湖入湖河流的野外调查中，稳定同位素与多光谱技术分析表明，类蛋白质物质主导了DOM的组成，占荧光总强度的74.98% ± 11.10%。δ¹³C-CH₄值（−31.18‰ ± 3.79‰）指示乙酸发酵产甲烷途径占据主导。进一步分析揭示，研究区内陆源类腐殖质物质的增加可能促进了碳排放。DOM降解实验进一步证实，DOM降解会促进CH₄的生成，其中光-生物联合降解释放的CH₄量超过了单一生物降解。此外，DOM降解过程中类腐殖质物质的消耗是促进CH₄产生的关键因素。本研究深化了对DOM降解与温室气体排放关系的理解，并为河流环境中温室气体的控制与减排提供了潜在策略。

（来源：Journal of Hydrology 2026  DOI: 10.1016/j.jhydrol.2025.134067）