| 引用本文: | 刘桂民,陈非洲,刘正文.太湖枝角类微化石的初步研究.湖泊科学,2008,20(4):470-476. DOI:10.18307/2008.0410 |
| LIU Gui-min,CHEN Fei-zhou,LIU Zheng-wen.Preliminar study on cladoceran microfossils in the sediments of Lake Taihu. J. Lake Sci.2008,20(4):470-476. DOI:10.18307/2008.0410 |
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| 摘要: |
| 湖泊沉积物中的枝角类微化石能够在一定程度上反映历史时期水体中的枝角类种群动态,从而具有重要的环境指示意义.通过对太湖(马山附近)沉积物中枝角类微化石的初步研究,尝试反演了所研究湖区近百年来水体环境的演化过程,并对枝角类种群动态的驱动因素进行了分析.从沉积物中共鉴定出10属14种枝角类,其中象鼻溞属占绝对优势,相对丰度平均值高达95.4%,尖额溞属次之,为4.2%;盘肠溞属以及其他枝角类不到1%.研究结果显示,随沉积深度自下而上变化,喜好富营养水体环境的B.longirostriscornuta和A.rectangula的丰度逐渐增加,而偏贫-中营养环境的A.intermedia的丰度则逐渐下降,表明水体营养水平处于逐渐上升的过程,其中表层3cm以上枝角类绝对丰度的急剧下降和A.intermedia的完全消失表明,20世纪80年代末期以来水体急剧富营养化;另外枝角类敞水区种类与沿岸带种类的数量比(P/L)随沉积深度的变化也在一定程度上反映了太湖水深/水面积的变化以及20世纪80年代末期以来的水体富营养化状况.研究结果同时也表明,20世纪60年代以前,自然环境条件为影响枝角类种群动态的主控因素,此后人类活动的影响越来越明显并最终成为枝角类种群动态的决定性因素. |
| 关键词: 太湖 枝角类 微化石 古湖沼学 |
| DOI：10.18307/2008.0410 |
| 分类号: |
| 基金项目:中国科学院知识创新项目(KZCX2-YW-419)资助 |
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| Preliminar study on cladoceran microfossils in the sediments of Lake Taihu |
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LIU Gui-min1,2, CHEN Fei-zhou1, LIU Zheng-wen1
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1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P.R.China;2.Graduate School of Chinese Academy of Sciences, Beijing 100049, P.R.China
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| Abstract: |
| Cladoceran microfossils can reflect the historical population dynamics and are an important indicator of paleoenvironments. The present study was aimed to analyze the historical variation of cladoceran assemblage and abundance, and its driving factors by examining cladoceran microfossil of the sediments in western Lake Taihu (near Mashan). A total of 14 cladoceran species belonging to 10 genera were identified. The most abundant species were planktonic Bosmina spp. with an average relative abundance of 95.4%; the second were Alona spp., with average abundance of 4.2%; Chydorus spp. and all the other species were less than 1%. The increasing tendency of nutrient levels of Lake Taihu was showed by the vertical changes of cladocera assemblage and abundance of the sediments. B. longirostris cornuta and A. rectangular, which prefer eutrophic conditions, showed an increasing tendency from bottom to upper layer, while A. intermedia, which commonly appearred in lower trophy, showed a decreasing tendency. The dramatic decrease of cladocera absolute abundance and the disappearance of A. intermedia at the surface 3cm sediments probably indicated the rapid nutrients loading since late the 1980s. In addition, the historically changes of water level/area and the increasing trophic states after the late the 1980s were represented by the ratio of plankontic to littoral species (P/L). Our results showed that natural conditions were the major factors which affected the population dynamics of cladocera before the 1960s, the human activities strengthened since the 1960s, and finally played the determinant role in the population dynamics of cladocera in Lake Taihu. |
| Key words: Lake Taihu cladoceran microfossils paleolimnology |
