Dynamic changes in size-fractionated dissolved organic matter composition in a seasonally ice-covered Arctic River

	Dynamic changes in size-fractionated dissolved organic matter composition in a seasonally ice-covered Arctic River
	Lin, Hui; Xu, Huacheng; Cai, Yihua; Belzile, Claude; Macdonald, Robie W.; Guo, Laodong
刊名	LIMNOLOGY AND OCEANOGRAPHY
	2021
卷号	66 期号:8 页码:3085-3099
英文摘要	Arctic rivers are sensitive to climate and environmental change, but the biogeochemical response remains poorly understood. Monthly size-fractionated dissolved organic matter (DOM) samples from the lower Yukon River were characterized using UV-visible, fluorescence, and Fourier transform-infrared (FT-IR) spectroscopy techniques. The EEM-PARAFAC analysis revealed three major fluorescent DOM components, including two humic-like components (C-480 and C-400) and one protein-like component (C-310), with their relative importance following the order of C-480 >= C-400 > C-310 in the high-molecular-weight DOM (1 kDa-0.4 mu m) and C-400 > C-480 > C-310 in the low-molecular-weight DOM pool (< 1 kDa). Transformation in DOM and change in sources were manifested in major fluorescent components and optical properties, including biological index (BIX), humification index (HIX), spectral slope (S275-295) and specific UV absorbance at 254 nm (SUVA(254)). These changes occurred within different DOM size-fractions and among ice-covered, spring freshet, and open seasons. Joint analysis of EEM and FT-IR spectra using a data fusion technique showed that humic-like DOM is mostly associated with CH, CC, and CO bonds, while protein-like DOM is correlated more with CN and NH related structures. DOM aromaticity and the ratios of HIX to BIX and protein-like to humic-like components may be used as a compelling proxy to measure change in source waters and to infer permafrost dynamics. Our results provide insight into the seasonal variation in DOM composition for different size-fractions in the lower Yukon River, and a baseline dataset against which future changes can be understood in the context of arctic basin biogeochemical cycling.
内容类型	期刊论文
源URL	[http://159.226.73.51/handle/332005/20494]
专题	中国科学院南京地理与湖泊研究所
推荐引用方式 GB/T 7714	Lin, Hui,Xu, Huacheng,Cai, Yihua,et al. Dynamic changes in size-fractionated dissolved organic matter composition in a seasonally ice-covered Arctic River[J]. LIMNOLOGY AND OCEANOGRAPHY,2021,66(8):3085-3099.
APA	Lin, Hui,Xu, Huacheng,Cai, Yihua,Belzile, Claude,Macdonald, Robie W.,&Guo, Laodong.(2021).Dynamic changes in size-fractionated dissolved organic matter composition in a seasonally ice-covered Arctic River.LIMNOLOGY AND OCEANOGRAPHY,66(8),3085-3099.
MLA	Lin, Hui,et al."Dynamic changes in size-fractionated dissolved organic matter composition in a seasonally ice-covered Arctic River".LIMNOLOGY AND OCEANOGRAPHY 66.8(2021):3085-3099.