气候变化领域集成服务门户(CCPortal): Spatial variations of DOM in a diverse range of lakes across various frozen ground zones in China: Insights into molecular composition

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DOI	10.1016/j.watres.2024.121204
	Spatial variations of DOM in a diverse range of lakes across various frozen ground zones in China: Insights into molecular composition
	Wen, Zhidan; Han, Jiarui; Shang, Yingxin; Tao, Hui; Fang, Chong; Lyu, Lili; Li, Sijia; Hou, Junbin; Liu, Ge; Song, Kaishan
发表日期	2024
ISSN	0043-1354
EISSN	1879-2448
起始页码	252
卷号	252
英文摘要	Dissolved organic matter (DOM) plays a significant role in aquatic biogeochemical processes and the carbon cycle. As global climate warming continues, it is anticipated that the composition of DOM in lakes will be altered. This could have significant ecological and environmental implications, particularly in frozen ground zones. However, there is limited knowledge regarding the spatial variations and molecular composition of DOM in lakes within various frozen ground zones. In this study, we examined the spatial variations of in -lake DOM both quantitatively, focusing on dissolved organic carbon (DOC), and qualitatively, by evaluating optical properties and conducting molecular characterization using Fourier -transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Lakes in cold regions retained more organic carbon compared to those in warmer regions, the comparison of the mean value of DOC concentration of all sampling sites in the same frozen ground zone showed that the highest mean lake DOC concentration found in the permafrost zone at 21.4 +/- 19.3 mg/L. We observed decreasing trends in E2:E3 and MLBL, along with increasing trends in SUVA254 and AImod, along the gradually warming ground. These trends suggest lower molecular weight, reduced aromaticity, and increased molecular lability of in -lake DOM in the permafrost zone compared to other frozen ground zones. Further FT-ICR MS characterization revealed significant molecular -level heterogeneity of DOM, with the lowest abundance of assigned DOM molecular formulas found in lakes within permafrost zones. In all studied zones, the predominant molecular formulas in -lake DOM were compounds consisted by CHO elements, accounting for 40.1 % to 63.1 % of the total. Interestingly, the percentage of CHO exhibited a gradual decline along the warming ground, while there was an increasing trend in nitrogen -containing compounds (CHON%). Meanwhile, a substantial number of polyphenols were identified, likely due to the higher rates of DOM mineralization and the transport of terrestrial DOM derived from vascular plants under the elevated temperature and precipitation conditions in the warming region. In addition, sulfur -containing compounds (CHOS and CHNOS) associated with synthetic surfactants and agal derivatives were consistently detected, and their relative abundances exhibited higher values in seasonal and short -frozen ground zones. This aligns with the increased anthropogenic disturbances to the lake's ecological environment in these two zones. This study reported the first description of in -lake DOM at the molecular level in different frozen ground zones. These findings underline that lakes in the permafrost zone serve as significant hubs for carbon processing. Investigating them may expand our understanding of carbon cycling in inland waters.
英文关键词	Dissolved organic matter; Frozen ground; Permafrost; Molecular composition; FT-ICR MS; Chinese lakes
语种	英语
WOS研究方向	Engineering ; Environmental Sciences & Ecology ; Water Resources
WOS类目	Engineering, Environmental ; Environmental Sciences ; Water Resources
WOS记录号	WOS:001174134800001
来源期刊	WATER RESEARCH
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/306551
作者单位	Chinese Academy of Sciences; Northeast Institute of Geography & Agroecology, CAS; Liaocheng University; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
推荐引用方式 GB/T 7714	Wen, Zhidan,Han, Jiarui,Shang, Yingxin,et al. Spatial variations of DOM in a diverse range of lakes across various frozen ground zones in China: Insights into molecular composition[J],2024,252.
APA	Wen, Zhidan.,Han, Jiarui.,Shang, Yingxin.,Tao, Hui.,Fang, Chong.,...&Song, Kaishan.(2024).Spatial variations of DOM in a diverse range of lakes across various frozen ground zones in China: Insights into molecular composition.WATER RESEARCH,252.
MLA	Wen, Zhidan,et al."Spatial variations of DOM in a diverse range of lakes across various frozen ground zones in China: Insights into molecular composition".WATER RESEARCH 252(2024).