【作者】 吴竹臣；

【导师】 陈立婧；

【作者基本信息】 上海海洋大学 ， 水生生物学， 2011， 硕士

【摘要】 明珠湖地处崇明岛西部绿华镇境内,面积为3km2,是崇明最大的天然淡水湖泊。其原是长江南支的一条支流,由上个世纪70年代经人工筑堤围造而成的潟湖,现建有二个进出水闸门,属通江湖泊。作为世博会的配套工程,同时作为崇明县计划开发的西部水上游乐度假区和西部生态农业观光旅游区的主要区域,对明珠湖的水质状况的监测就显得十分必要了。本次研究于2007年至2009年对明珠湖浮游植物的群落结构及物种多样性进行了调查,分析了浮游植物群落结构变化与环境因子的相关性,并对3年明珠湖的水质进行了生态学评价,以了解该水体中浮游植物的群落结构特征的变化规律,为明珠湖水质的监测与水体生态环境的保护提供了基础生物学依据。1、2007年至2009年明珠湖共鉴定浮游植物8门88属168种。其中,绿藻门最多,为38属78种,占总数的47%;其次为蓝藻门20属38种,占总数的23%;硅藻门17属25种,占总数的23%;其余分别为裸藻门4属9种,黄藻门4属6种,甲藻门2属6种,金藻门1属4种。2、明珠湖浮游植物3年平均生物密度为4650.24×104cell·L-1,3年平均生物量为6.06 mg·L-1。明珠湖3年生物密度主要是蓝藻门占优势,其次为绿藻门,硅藻门第三。浮游植物生物量也主要以蓝藻门为主,占到各年的50%以上。其次为硅藻门,绿藻门第三。其余浮游植物门类的生物密度和生物量在总量中所占比例均较少,变化不大。生物密度与生物量周年变化趋势均表现为单峰型,各月间差异明显,但站点间无显著差异。3、明珠湖2007-2009年3年浮游植物优势种共5种,包括小席藻(Phormidium tenue)、微小平裂藻(Meismopedia tenuissima)、宽松螺旋藻(Spirulina laxissima)、旋折平裂藻(M. convolute)、肘状针杆藻(Synedra ulna)。3年优势种的演替规律均基本符合PEG模型所述:浮游植物冬春以硅藻为主,转变为夏季的绿藻,到夏末秋初则以蓝藻占优势。4、本次的实验表明影响明珠湖浮游植物群落结构最主要的环境因子为水温。从3年的CCA可看出,明珠湖浮游植物的现存量和各环境因子的相关性都非常好。运用SPSS软件分析3年数据发现,明珠湖2007年至2009年生物密度、生物密度与水温以及pH呈显著正相关关系,与透明度、总氮呈显著负相关关系,与总磷、溶氧呈负相关关系。5、2007-2009年浮游植物的Shannon-Wiener多样性指数三年均值为2.14±0.45。Margalef多样性指数2007到2009年3年均值为2.52±0.69。Pielou均匀度指数2007到2009年3年平均值为0.58±0.16。明珠湖2007年至2009年修正的卡尔森指数3年平均值为53.03±7.96。Shannon-Wiener多样性指数和Pielou均匀度指数表现为冬春低,夏秋高的变化趋势;而Margalef多样性指数和修正的卡尔森指数的变化趋势则相反。6、综合多种评价方法的评价结果可见,明珠湖2007年、2008年处于中富营养,α-中污染型;2009年属于中营养型,α-中污染型。水体富营养化正在逐步减轻,水质逐年变好。更多还原

【Abstract】 Mingzhu Lake is located in the western Lvhua town of Chongming Islaand. It has an area of 3km2, and is the largest natural freshwater lake in Chongming Island. It was a tributary of the Yangtze River of south branch and an artificial embankment in seventies of last century. Now the Mingzhu Lake has two sluice gates for inletting and draining water. As the auxiliary project of Shanghai Word Expo and master region of westen water entertainment and ecological agriculture tourist area of the Chongming Island, monitoring water quality of this lake is much more necessary. The study on the community structure and species diversity of Phytoplankton based on the monitor of physical and chemical index and biology index,analyze and discuss the relativity between water quality of Mingzhu Lake and environmental factor lasted 3 years from January 2007 to December 2009.It offered the ecological assessment of Mingzhu Lake and the evolution of community structure of phytoplankton, and also prouvde the basic ecology date for monitoring the water quality and protecting the ecology environment of Mingzhu Lake.1、The phytoplankton community structure and the annual variation of species multiplicity in Mingzhu Lake, Chongming Island were primarily studied from January 2007 to December 2009. A total of 168 species of phytoplankton belonging to 8 phyla, 88 genera were observed in the Lake. The dominant species ascribing to Chlorphyta accounted for 47 percent and the quality is 78 species belonging to 25 Genera; Secondly the percentage of Cyanophyta is 23 percent and the quality was 38 species which belonging 20 Genera; The third was Bacillariophyta accounted for 23 percent and the quality was 25 species belonging to 17 Genera; The others were Euglenophyta、Xanthophyta、Pyrrophyta、Chrysophyta. 2、The annual average densities and biomass of phytoplankton were 4650.24×104cell·L-1 and 6.06 mg·L-1, respectively. On the issue of phytoplankton densities, it appears that Cyanophyta was the dominant kind. Chlorphyta、Bacillariophyta were also important to the construction of densities. The Cyanophyta also was the dominant kind of phytoplankton biomass. The Bacillariophyta was the secondly dominant kind and the Chlorphyta was the Third one. The rest of the phytoplankton densities and biomass were rare. The density and biomass in Mingzhu Lake have the seasonal variation, and it was lower in winter and spring, and higher in summer and autumn. However, there was no obviously differences between sites.3、There were 5 kinds of dominant species from 2007 to 2009, including Phormidium tenue、Meismopedia tenuissima、Spirulina laxissima、M. convolute、Synedra ulna. The law of succession of phytoplankton was consistent with PEG (Plankton Ecology Group) model, except the Chlorophyta : The Bacillariophyta is the dominant species in winter and spring, in summer the dominant species changed from Bacillariophyta to Chlorphyta, and till to autumn the dominant species would be the Cyanophyta.4、The result showed that the water temperature was the main factors affecting the phytoplankton distribution. We can see from the result of CCA, it had a great relationship between environmental factor and the standing crop of phytoplankton. The result by SPSS showed that the relationship between the density and biomass of phytoplankton and the physical and chemical factors were the density and biomass has a significant positive correlation between water temperature and pH, but a significant correlation between transparency and total nitrogen, and a negative correlation between total phosphorus and dissolved oxygen.5、The average value of Shannon-Wiener diversity of phytoplankton in Mingzhu Lake from 2007 to 2009 was 2.14±0.45, the average value of Margalef species richness index was 2.52±0.69, the average value of Pielou evenness index was 0.58±0.16. the average value of trophic state index(TSI) was 53.03±7.96. The Shannon-Wiener diversity and Pielou evenness index has the same law: The numerical value in spring and winter were higher than those in the other two seasons. On the contrary, the Margalef species richness index and TSI were higer in summer and autumn.6、Utilizing all kinds of methods of evaculations, the water quality of Mingzhu Lake in 2007、2008 lies in the status of semi-eutrophication. And in 2009, the Mingzhu Lake was moderately pollution. The water quality has trend of gradually changing.更多还原