龙感湖地区近3000年来的气候环境变迁  

The Palaeoenvironmental and Palaeoclimatic Changes of Longgan Lake since the Past 3000 Years

作　　者：瞿文川[1] 吴瑞金[1] 羊向东[1] 王苏民[1] 吴艳宏[1] 薛滨[1] 童国榜[2] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊沉积与环境开放实验室,南京210008 [2]地质矿产部水文地质工程研究所,正定050803

出　　处：《湖泊科学》1998年第2期37-43,共7页Journal of Lake Sciences

基　　金：中国科学院湖沼专项和国家九五攀登资助

摘　　要：本文通过分析龙感湖沉积物中的色素、孢粉、硅藻研究结果，探讨该区近3000年来环境气候波动特点．结果表明：3200一2400aBP，色素含量较高，与温度条件较好有关．该带孢粉浓度也最高，阔叶乔木树种花粉丰富，湿生及水生植物经常出现．总体上为相对暖湿阶段，其中仍有凉湿波动．2400－1600aBP，具体分为两个阶段，前期约2400－2000aBP．CD、TC、Myx含量明显较低，水生、湿生草本减少，气候偏凉干；后期各种色素含量均升高，与暧性木本属种增多相对应．表明气温有升高趋势．这一时期色素总体含量较上一阶段略低，与孢粉组合反映的气候温凉略湿特征一致．1600－1500aBP，该段CD、TC、Osc、Mry均为谷值．反映湖泊生物量减少，富营养化程度低，对比孢粉曲线其木本为谷值段，以禾本科为主，气候上反映为明显的降温事件．1500－1100aBP，CD、NC、TC、Osc及Myx含量均明显增大．湖泊生产力有所提高，反映了此时期气候好转，这也与孢粉资料吻合．1100－100aBP，整个阶段色素含量低，达到整个剖面的最低段．湖泊富营养化程度低，水质好转．而孢粉资料表明此阶段孢粉浓度低，针叶花粉增多，反映气温低，植被不发育，与色素结果对比较好．时段上相当小冰期．100aBP至今，各项色素含量明显增高，一方面反映湖泊的水体?According to the contents and assemblages of pigments. diatom and sporex-pollen from the sediments core of Longgan lake, Anhui Province. this paper mainly deals with the climatic and environmental changes during the last 3000 years in Longgan Lake. The environment of this region changed as follows:During 3200- 2400aBP, the contents of CD, NC, TC were high, reflecting higher like productivity. The higher pigment value of Osc and Myx were relative to the temperature condition. moreover the abundance of vegetation, higher water temperature and lower turbidity could strengthen the competition of blue algae. Pollen concentration had the highest point comparing other stages, decious tree pollen was very abundant and also often occur other pollen of water and wet plants representing a relative warm and wet period with a cool - dry oscillation.During 2400 - 1600aBP, this period may be divided into two stages. In early period (about 2400- 2070aBP), the contents of CD,TC,Myx decreased obviously. some herbs such as Artemisia. Palygonum increased while other water and wet herbs decreased. indicating a cool-dry climate ; lately all the pigment percentages increased , indicating a higher temperature tend. Compared to first stages, the content of pigment at the stage was lower.inferring a tame cool and little wet climate.During 1600 - 1500 aBP, the lower pigment value of CD, TC,Osc and Myx showed that lake biomass reduced and the lake was extremely trophic. Meanwhile arboreal was in its valley period.During 1500- 1100 aBP, the contents of CD, TC. Myx increased obvlously. reflecting higher producidivity and a higher temperature tendency.1100 - 100 aBP, pigment percentage and pollen concentration decreased to its lowest point of the whole section. It indicate a cool and dry climate reflecting as Little Ice Age.100 aBP-present. the higher value of pigment of surface sediment may be related to the eutrophic status of the lake which maybe caused by the human activity.

关 键 词：色素 龙感湖 沉积物 硅藻 古环境 古气候 

分 类 号：P532[天文地球—古生物学与地层学] P531[天文地球—地质学]