Diatom community succession in the recent history of a eutrophic Yunnan Plateau lake, Lake Dianchi, in subtropical China
Diatom community succession in the recent history of a eutrophic Yunnan Plateau lake, Lake Dianchi, in subtropical China
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中国亚热带云南高原富营养化湖泊滇池近代史上硅藻群落演替
DOI：
10.1007/s10201-009-0282-8
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发表时间：
2009-12-01
期刊：
影响因子：
1.6
通讯作者：
Xie, Ping
中科院分区：
文献类型：
--
作者：
Gong, Zhi-jun;Li, Yan-ling;Xie, Ping
鱼类的引入、水体的富营养化和水生植被的消失是水生态系统的重要干扰，尤其是在被普遍认为是非常脆弱的高原湖泊。在20世纪50年代末和70年代，鱼类被引入中国西南部富营养化的高原湖泊滇池。引进后，入侵鱼类成为优势种，鱼类总产量增加。同时，由于流域内人类活动的增加，滇池的营养水平在过去的几十年里有上升的趋势。此外，从20世纪50年代到2000年，水生植被面积从湖泊面积的90%以上减少到1.8%。通过对滇池硅藻微体化石组合和丰度的变化研究，探讨了鱼类引入、富营养化和水生植被对滇池硅藻群落的影响。结果表明，引入鱼类后，硅藻绝对丰度和组合发生了变化。1958年后，随着鱼类的引入和营养水平的提高，特有种椭圆小环藻逐渐消失; 1958年后，随着鱼类的引入，巴豆脆杆藻进入湖中，并逐渐在湖中繁殖。硅藻种类也从过去的21种逐渐减少到现在的9种。1985年以后，随着水生植被的减少，附生硅藻逐渐消失。研究表明，富营养化是决定硅藻丰度的最重要的过程，鱼类的引入是决定硅藻丰度的次要过程，而水生植被对该富营养化高原湖泊硅藻群落结构的形成起着更为重要的作用。
Fish introduction, eutrophication and disappearance of aquatic vegetation are important disturbances of aquatic ecosystems, especially in plateau lakes, which are generally considered to be very vulnerable. Fish were introduced to Lake Dianchi, a eutrophic plateau lake in southwest China, in the late 1950s and 1970s. After the introduction, invasive fish became the dominant species, and the total fish yield increased. Meanwhile, the trophic level of Lake Dianchi had a tendency to increase in the past decades because of the increases in human activities in the watershed area. In addition, the area of aquatic vegetation decreased from more than 90 to 1.8% of the lake area from the 1950s to 2000. This study investigated the effects of fish introduction, eutrophication and aquatic vegetation on the diatom community of Lake Dianchi by examining the changes of microfossil diatom assemblage and abundance. Results showed that the absolute abundance and diatom assemblages changed after fish were introduced. The endemic species,Cyclotella rohomboideo-elliptica, disappeared with the introduction of fish and increasing trophic levels after 1958.Fragilaria crotonensisentered into the lake with the introduction of fish and gradually thrived in the lake after 1958. Diatom species numbers also decreased gradually from 21 to 9 from the past to present. Epiphytic diatoms disappeared with the decrease of aquatic vegetation after 1985. Our study indicated that eutrophication was the most important process determining diatom abundance, and fish introduction was a secondary process determining diatom abundance, while aquatic vegetation had a more important role in structuring the diatom community in this eutrophic plateau lake.