Feedback of threshold via estimating sources and composition of sedimentary organic matter across trophic gradients in freshwater lakes

Xiaoguang Xu, Wei Li, Megumu Fujibayashi, Munehiro Nomura, Takashi Sakamaki, Osamu Nishimura, Xianning Li

研究成果: ジャーナルへの寄稿学術誌査読

16 被引用数 (Scopus)


The quantity and quality of sedimentary organic matter (SOM) in relation to material and energy flows are crucial for understanding the current state and future development of lake systems, yet, characterization of organic matter sources and assessment of their relative contributions in different trophic-state lakes caused by anthropogenic impacts are scarcely known. In this study, for obtaining information concerning the source of SOM and its compositional diversity along different trophic gradients, a total of thirty-one sampling sites from four freshwater lakes located in China and Japan were performed by the molecular level analysis using source-specific fatty acid biomarkers. Results indicated that SOM in these lakes was composed of microalgae-, aquatic plant-, terrestrial plant- and bacteria-derived organic matters based on their fatty acid profiles. The scatter plot matrix exhibited correlations between these sources, however, only terrestrial plant-derived organic carbon was a well predictor for sediment TOC with strong, spatiotemporal dynamics. The source and composition of SOM were evidently influenced by lake trophic state with redundancy analysis. Moreover, increase of lake trophic state led to the relatively higher contribution of aquatic organic matter sources to SOM pool compared with terrigenous sources, as evidenced by significant correlations between the trophic state index [TSI (TP)] and the ratio of terrigenous to aquatic fatty acids (TARFA ratio). Yet, this changing trend became more gradual with higher trophic state and prevented the occurrence of regime shift from allochthonous to autochthonous dominant state by a threshold (0.683) of TARFA ratio. Together, a conceptual diagram was proposed, which highlighted the prevailing state of allochthonous source and implicated sedimentary organics in biogeochemistry cycle within freshwater lakes.

ジャーナルScience of the Total Environment
出版ステータス出版済み - 12月 1 2014

!!!All Science Journal Classification (ASJC) codes

  • 環境工学
  • 環境化学
  • 廃棄物管理と処理
  • 汚染


「Feedback of threshold via estimating sources and composition of sedimentary organic matter across trophic gradients in freshwater lakes」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。