滇池近代富营养化加剧过程的沉积记录  

Sedimentary Records of Accelerated Eutrophication in Dianchi Lake over the Recent Decades

作　　者：刘勇[1,2] 朱元荣[2,3] 弓晓峰[1] 谢发之[2] 廖海清[2] 吴代赦[1] 吴丰昌[2] 

机构地区：[1]南昌大学环境与化学工程学院,江西南昌330031 [2]中国环境科学研究院,环境基准与风险评估国家重点实验室,北京100012 [3]北京师范大学水科学研究院,北京100875

出　　处：《环境科学研究》2012年第11期1236-1242,共7页Research of Environmental Sciences

基　　金：国家重点基础研究发展计划(973)项目(2008CB418200);中央级公益性科研院所基本科研业务专项(2010KYYW04);国家自然科学基金项目(U0833603)

摘　　要：为认识滇池内源污染特性在湖泊环境演变过程中的变化,采集滇池北部和中心2根柱状沉积物样品,分析了TOC(总有机碳)、TN(总氮)、BSi(生物硅)及磷形态含量剖面变化规律,并探讨了其与滇池富营养化历史的关系.结果表明,滇池沉积物中w(TOC)与w(TN)自20世纪50年代后增加显著.n(TOC)/n(TN)介于7.0～13.5之间,表明滇池内源藻类和细菌等对沉积物中有机质贡献大.滇池沉积物中w(TP)剖面变化规律反映了滇池由中营养化向富营养化过渡的过程.沉积物中w(TP)与w(TOC)呈显著相关(R=0.91,P<0.01),表明滇池外源磷的输入与生物量的增长以及蓝藻水华暴发的一致性和外源磷污染控制的必要性.滇池不同区域w(BSi)剖面变化及其与w(TOC)、w(TP)的关系表明,滇池在长期演变中,生态系统结构发生了变化.滇池北部近年来富营养化加剧,蓝藻大量繁殖成为优势种群而导致生物群落结构单一化;而中部等地区硅藻仍保持大量增长趋势,表明藻类在该区域处于大量增长的过程中.In order to investigate the changes in pollution characteristics and lake environment evolutionary processes in Dianchi Lake, samples from two sediment cores from the northern and central parts of the lake werecollected, and the vertical distributions of total organic carbon （TOC）, total nitrogen （TN）, biogenie silica （BSi） and phosphorus fractions were investigated. The relationship between the changes of these parameters and the eutrophication history of the lake was also discussed. The results showed that the concentrations of TOC and TN had been clearly increasing since the 1950s. The atomic ratios of TOC/TN were from 7.0 to 13.5, which suggested that organic matter in the sediments were probably mainly the endogenous blue algae and bacteria. The change of TP concentration along with depth of the sediments showed a transition process from mesotrophication to eutrophication of the lake. Concentration of TP was strongly and positively correlated with TOC concentration （R =0.91, P 〈0.01）, which suggested the co-occurrence of phosphorus input, growth of biomass and algae blooming, and indicated the importance of the controlling exogenous phosphorus. Vertical variation of BSi concentrations and its correlation with TOC and TP concentrations showed that during the long-term evolution of Dianchi Lake, the structure of the ecosystem changed. Eutrophication in Dianchi Lake has become more severe in recent years, and the blue algae has spread greatly. In the central part of the lake, the community of diatoms was increasing, which indicated an increase of algae in this area.

关 键 词：沉积物 碳 氮 磷形态 生物硅(BSi) 滇池 

分 类 号：X524[环境科学与工程—环境工程]