【作者】 许夏玲；

【导师】 王全喜；

【作者基本信息】 上海师范大学 ， 水生生物学， 2008， 硕士

【摘要】 滴水湖是在海滩滩涂上修建的大型湖泊,目前是国内最大的城市景观人工湖,湖水通过大治河引自黄浦江。我们于2007年1月至12月对滴水湖及农场中心河进行12次采样调查,共设置9个采样点,其中滴水湖8个采样点,农场中心河1个采样点。我们对滴水湖及农场中心河水体的理化指标、浮游植物群落结构组成及变化规律作了较细致的调查研究,利用多样性指数分析了浮游植物的多样性,分析浮游植物与环境因子之间的相互关系,并对水体的营养程度进行评价,为今后该水体环境保护工作提供本底资料,也为滩涂湖泊(水库)的研究提供基础资料。本研究得出如下结果:1.滴水湖年平均水温为18.25℃,变化幅度在6.1~28.8℃;湖区各点之间透明度差异不大,平均值为50.6cm,而农场中心河略高为56.5cm;pH值为碱性,平均值9.00;盐度平均值为2.81g/1000g,比一般湖泊高,主要受滩涂底泥的影响;湖区溶解氧(平均值9.98mg/L)、COD(平均值12.38 mg/L)、TN(平均值1.12mg/L)、TP(平均值0.10 mg/L)变化不大,根据TN/TP的结果,滴水湖为氮限制型湖泊。2.浮游植物共鉴定到55属86种,大部分是淡水藻类,隶属于8个门;优势藻类是绿藻门,23属43种,占总数的50.0%;其次是蓝藻门,9属17种,占总数的30.4%;硅藻门12属14种;占总数的16.3%。优势种:湖区主要有单鞭金藻属Chromulina、衣藻Chlamydomonas、纤维藻Ankistrodesmus、颤藻Oscillatoria、卵形藻Cocconeis;农场中心河主要有金藻门的单鞭金藻Chromulina、绿藻门的衣藻Chlamydomonas sp和尖头藻Raphidiopsis硅藻门的角毛藻Chaetoceros和小环藻Cylotella、隐藻门的隐藻Cryptomonas。在种类的季节变化上,种类与属的变化趋于一致,在2月份最少,5月份鉴定到种类最多;湖区种类最多的绿藻对整体变化趋势影响最大。浮游植物群落表现出小型化,数量大的特点。个体数量最大值出现在5月份,最小值出现在7月份。滴水湖生物量的季节变化受单鞭金藻的影响最大。叶绿素a的年平均浓度是29.35mg/m3,其水平及季节分布情况同浮游植物生物量一致。3.对滴水湖理化指标和生物指标进行相关分析。结果是:浮游植物的数量生物量与盐度、DO、SD相关性强;盐度与浮游植物数量生物量、单鞭金藻、DO、SD相关性较强;可见盐度是连接浮游植物和理化指标的桥梁。4.运用各理化指标、浮游植物指标及修正后的卡尔森营养状态指数等指标对滴水湖营养状态进行评价,结果为理化指标、叶绿素a和优势藻类均为中富营养状态;生物量、总TSI为富营养状态。各指标的评价结果存在差异,表明以单因子评价滴水湖的富营养化程度存在一定的局限性。综合分析认为滴水湖的水质整体处于中度富营养化水平。更多还原

【Abstract】 Dishui Lake is a large newly-bulit lake on beach, so far it is the largest man-made landscape lake in our country. This research on Dishui Lake and its around waters has 9 sample sites (8 sites in Dishui Lake), sample every month from January to October in 2007. The delicate research of the community structure and distribution of phytoplankton is based on the monitor of physichemical index , analyze the diversity of phytoplankton using diversity index, analyze and discuss the relationship of phytoplankton and physichemical index in the meanwhile using these factors to value water quality. All these work can provide most basic data for the protection of environment and the material for the research on river or reservoir. Here are the results:1. The yearly average temperature of Dishui Lake is 18.25 degrees, the variable span is from 6.1 degrees to 28.8 degrees; there is no difference on transprancy between differents sites, the average is 50.6 centimetres, but the around waters, is higher than the lake, It is 56.5 centimetres; the average PH is 9.00, which showed the quality took on alkaline; the average salinity affected by the beach is 2.81g/1000g, higher than the other lakes; there is no big change on averages of OD(9.98mg/L), COD(12.38mg/L), TN(1.12mg/L), TP(0.10mg/L), according to the ratio of TN/TP, Dishui Lake is P-limited lake.2. There are 86 species of phytoplankton, which belonged to 55 genera of 8 phyla.Most of them are freshwater species; dominant species ascribing to Chlorophyta accounted for 50 percents and the quantity is 43 species belonging to 23 Genera; secondly the percentage of Cyanophyta is 30.4. Chromulina, Chlamydomonas, Ankistrodesmus, Oscillatoria, Cocconeis are dominant species in Dishui Lake, but the dominant species of its around waters are Chromulina, Chlamydomonas, Raphidiopsis, Chaetoceros, Cylotella and Cryptomomas. The same change occurred between species and generas on the seasonal change, the minority in January and the majority in May; the Chla which accounted for the most propotion can influence the entire change trendency of phytoplankton.Phytoplankton community structure takes on a trait of little-shape and large number . The largest number of the spceies appeared in May. The seasonal change of phytoplankton biomass could be influenced mostly by Chromulina in Dishui Lake. The yearly average concentration of Chla is 29.35mg/m3, and its horizontal and seasonal distribution just coincidenced with biomass of phytoplankton.3.The correlation analysis on the physichemical index and biological index of Dishui Lake: There is strong correlation between the quantity and salinity、DO、SD. And the strong correlation also lies in the relationship of salinity and quantity of phytoplankton、Chromulina、DO、SD. So we can conclude that sanlinity is the bridge of phytoplankton and physichemical index.4.Evaluation about eutrophication of Dishui Lake using physichemical index、phytoplankton index and corrected Carlson Trophic State indexes.All results showed different, some factors included physichemical index, Chromulina and the dominant species showed that the lake was in a status of semi-eutrophication, but using the biomass and TSI showed the result was eutrophication. All this showed that to value the status of eutrophication has some restrictions using signal index. So that the water quality of Dishui Lake lies in the status of semi-eutrophication.更多还原