Characteristics and sources of chromophoric dissolved organic matter in lakes of the Yungui Plateau, China, differing in trophic state and altitude
Characteristics and sources of chromophoric dissolved organic matter in lakes of the Yungui Plateau, China, differing in trophic state and altitude
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DOI：
10.4319/lo.2010.55.6.2645
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发表时间：
2010-11-01
影响因子：
4.5
通讯作者：
Qin, Boqiang
中科院分区：
文献类型：
--
作者：
Zhang, Yunlin;Zhang, Enlou;Qin, Boqiang
云贵高原高山湖泊受高强度紫外线照射，含有低浓度的有色溶解有机物（CDOM）。对云贵高原海拔1516 ~ 4591 m的38个湖泊中CDOM的吸收、荧光、组成和来源进行了测定。总氮（TN）、总磷（TP）和叶绿素a（Chl a）浓度随营养状态的增加而显著增加，随海拔的升高而降低。CDOM吸收系数a（CDOM）（280）随营养状态的增加而显著增加，但不随海拔的升高而增加。海拔高度与TN、TP、Chl a浓度和a（CDOM）（280）呈显著负相关。平行因子分析确定了两个腐殖类和两个蛋白质类荧光成分。类腐殖酸组分1是terrestrially衍生和CDOM吸收呈正相关。成分2类似于海洋腐殖类物质，源于浮游植物的生物降解。组分3和组分4为内源性类酪氨酸荧光团和类色氨酸荧光团。因此，CDOM是集水区物质和湖中生物群产生的本地物质的混合物。贫营养型和中营养型湖泊的CDOM荧光特征以类蛋白质组分为主，而富营养型湖泊以海洋和陆地类腐殖酸组分为主。荧光指数FI 255、FI 310和FI 370可用于云贵高原湖泊沃茨CDOM特征的定性和分类。
The high-mountain lakes on the Yungui Plateau in China are exposed to high-intensity ultraviolet radiation, and contain low concentrations of chromophoric dissolved organic matter (CDOM). We determined CDOM absorption, fluorescence, composition, and source in 38 lakes on the Yungui Plateau at altitudes of 1516 to 4591 m above sea level. Total nitrogen (TN), total phosphorus (TP), and chlorophyll a (Chl a) concentrations significantly increased with increasing trophic state, and decreased with altitude. The CDOM absorption coefficient a(CDOM)(280) significantly increased with increasing trophic state, but not with altitude. There were significant and negative correlations between altitude and TN, TP, Chl a concentrations, and a(CDOM)(280). Parallel factor analysis identified two humic-like and two protein-like fluorescent components. Humic-like component 1 was terrestrially derived and positively correlated to CDOM absorption. Component 2 was similar to a marine humic-like substance originating from biological degradation of phytoplankton. Components 3 and 4 were autochthonous tryptophan-like and tyrosine-like fluorophores. CDOM was, thus, a mixture of material from the catchment and autochthonous material produced by biota in the lake. CDOM fluorescence characteristics of oligotrophic and mesotrophic lakes were dominated by the spectral signatures of protein-like components, but marine and terrestrial humic-like components dominated in eutrophic lakes. The fluorescence indices FI255, FI310, and FI370 were useful tools for readily defining and classifying CDOM characteristics in the Yungui Plateau lake waters.