Han Xiu-Xiu, Huang Xiao-Hu, Yu Li-Yan, Yang Hao, Huang Chang-Chun, Huang Tao, Yu Yan-Hong, Luo Yu
Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China.
Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing 210023, China.
Huan Jing Ke Xue. 2017 Jan 8;38(1):78-86. doi: 10.13227/j.hjkx.201606051.
Sediment columns in the southeast and east of Dianchi Lake were taken as the object of the study to determine ages by Pb dating method.The contents and sediment fluxes of total organic carbon (TOC) and -alkanes of the sediments were investigated,and organic sources were tracked according to the relevant indexes of -alkanes.The results indicated that TOC contents and sediment fluxes of two sampling sediments both presented an increasing trend on the whole;Sediment fluxes of -alkanes varied as three stages:increasing period,decreasing period and re-increasing period.When the sediment fluxes of -alkanes and TOC both went up,it showed that they had the same sources:sediments in the lake and carried by the rivers;From 1980s to the end of 20 century,sediment fluxes of -alkanes were going down while those of TOC were going up.This result means there was a big difference in the sources of -alkanes and TOC.The bacteria and algae in the lake made a great contribution to -alkanes while TOC was mainly influenced by sediments in the lake and carried by the rivers.-alkanes of the two sampling sites both ranged from C to C.Based on the basic features and relevant indexes of -alkanes,we proposed that emergent plants made big contributions to the sources of organic matter in the sediments of Dianchi Lake,simultaneously,bacteria and algae had significant contributions to the sources of organic matter in shallow depth of Dianchi Lake.
以滇池东南部和东部的沉积物柱为研究对象，采用铅测年法测定年代。研究了沉积物中总有机碳（TOC）和正构烷烃的含量及沉积通量，并根据正构烷烃的相关指标追踪有机来源。结果表明，两个采样沉积物的TOC含量和沉积通量总体上均呈上升趋势；正构烷烃的沉积通量变化分为三个阶段：上升期、下降期和再上升期。当正构烷烃和TOC的沉积通量均上升时，表明它们具有相同的来源：湖泊沉积物和河流携带的沉积物；从20世纪80年代到20世纪末，正构烷烃的沉积通量下降而TOC的沉积通量上升。这一结果意味着正构烷烃和TOC的来源存在很大差异。湖泊中的细菌和藻类对正构烷烃贡献很大，而TOC主要受湖泊沉积物和河流携带的沉积物影响。两个采样点的正构烷烃均在C至C范围内。基于正构烷烃的基本特征和相关指标，我们提出挺水植物对滇池沉积物中有机质来源贡献很大，同时，细菌和藻类对滇池浅水区有机质来源有显著贡献。
