期刊
WATER RESEARCH
卷 150, 期 -, 页码 403-417出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.watres.2018.12.004
关键词
Absorption; CDOM; EEMs; Freshwater; Saline water
资金
- National Natural Science Foundation of China [41871234, 41730104]
- hundred-talent program from Chinese Academy of Sciences
- Strategic Priority Research Program of the Chinese Academy of Sciences [XDA19070501]
Colored dissolved organic matter (CDOM) is a major component of DOM in waters, and plays a vital role in carbon cycling in inland waters. In this study, the light absorption and three-dimensional excitation emission matrix spectra (EEMs) of CDOM of 936 water samples collected in 2014-2017 from 234 lakes in five regions across China were examined to determine relationships between lake water sources (fresh versus saline) and their fluorescence/absorption characteristics. Results indicated significant differences regarding DOC concentration and a(CDOM)(254) between freshwater (6.68 mg C L-1, 19.55 m(-1)) and saline lakes (27.4 mg C L-1, 41.17 m(-1)). While humic-like (F-5) and fulvic-like (F-3) compounds contributed to CDOM fluorescence in all lake waters significantly, their contribution to total fluorescence intensity (F-T) differed between saline and freshwater lakes. Significant negative relationships were also observed between lake altitude with either F-5 (R-2 = 0.63, N = 306) or F-T (R-2 = 0.64, N = 306), suggesting that the abundance of humic-like materials in CDOM tends to decrease with increased in lakes altitude. In high altitude lakes, strong solar irradiance and UV exposure may have induced photo-oxidation reactions resulting in decreased abundance of humic-like substances and the formation of low molecular weight compounds. These findings have important implications regarding our understanding of C dynamics in lacustrine systems and the contribution of these ecosystems to the global C cycle. (C) 2018 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据