气候变化领域集成服务门户(CCPortal): Dissolved organic matter composition and reactivity in Lake Victoria, the world’s largest tropical lake

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DOI	10.1007/s10533-020-00687-2
	Dissolved organic matter composition and reactivity in Lake Victoria, the world’s largest tropical lake
	Deirmendjian L.; Lambert T.; Morana C.; Bouillon S.; Descy J.-P.; Okello W.; Borges A.V.
发表日期	2020
ISSN	0168-2563
起始页码	61
结束页码	83
卷号	150 期号:1
英文摘要	We report a data set of dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition (stable carbon isotope signatures, absorption and fluorescence properties) obtained from samples collected in Lake Victoria, a large lake in East Africa. Samples were collected in 2018–2019 along a bathymetric gradient (bays to open waters), during three contrasting seasons: long rainy, short rainy and dry, which corresponded to distinctly water column mixing regimes, respectively, stratified, semi-stratified and mixed regimes. Eight DOM components from parallel factor analysis (PARAFAC) were identified based on three-dimensional excitation–emission matrices (EEMs), which were aggregated into three main groups of components (microbial humic-like, terrestrial humic-like, protein-like). Spatially, the more productive bays were characterized by higher DOM concentration than deeper more offshore waters (fluorescence intensity and DOC were ~ 80% and ~ 30% higher in bays, respectively). Seasonally, the DOM pool shifted from protein-like components during the mixed regime to microbial humic-like components during the semi-stratified regime and to terrestrial humic-like components during the stratified regime. This indicates that pulses of autochthonous DOM derived from phytoplankton occurred when the lake was mixing, which increased the availability of dissolved inorganic nutrients. Subsequently, this freshly produced autochthonous DOM was microbially processed during the following semi-stratified regime. In the open waters, during the stratified regime, only terrestrial refractory DOM components remained because the labile and fresh stock of DOM created during the preceding mixed season was consumed. In the bays, the high terrestrial refractory DOM during the stratified regime may be additionally due to the allochthonous DOM input from the runoff. At the scale of the whole lake, the background refractory DOM probably comes mainly from precipitation and followed by river inputs. © 2020, Springer Nature Switzerland AG.
英文关键词	Carbon cycle; Colored dissolved organic matter; Dissolved organic carbon; Fluorescent dissolved organic matter; Lake Victoria; Tropical lake
语种	英语
scopus关键词	bathymetry; carbon isotope; concentration (composition); dissolved organic matter; factor analysis; lake water; phytoplankton; reaction kinetics; water column; East African Lakes; factor analysis; Lake Victoria
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153117
作者单位	Chemical Oceanography Unit, University of Liège, Liège, Belgium; Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland; Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium; National Fisheries Resource Research Institute, Jinja, Uganda; Geosciences Environnement Toulouse UMR 5563 & UR 234 IRD, Université Paul-Sabatier, Avenue Edouard Belin 14, Toulouse, 31400, France
推荐引用方式 GB/T 7714	Deirmendjian L.,Lambert T.,Morana C.,等. Dissolved organic matter composition and reactivity in Lake Victoria, the world’s largest tropical lake[J],2020,150(1).
APA	Deirmendjian L..,Lambert T..,Morana C..,Bouillon S..,Descy J.-P..,...&Borges A.V..(2020).Dissolved organic matter composition and reactivity in Lake Victoria, the world’s largest tropical lake.Biogeochemistry,150(1).
MLA	Deirmendjian L.,et al."Dissolved organic matter composition and reactivity in Lake Victoria, the world’s largest tropical lake".Biogeochemistry 150.1(2020).