沙湖浮游动物群落结构及其与水质因子关系的研究

宁夏大学硕士学位论文沙湖浮游动物群落结构及其与水质因子关系的研究姓名：孙晓雪申请学位级别：硕士专业：动物学指导教师：邱小琮2011-04摘要于2008年4月（春）、7月（夏）、10月（秋）、2009年1月（冬）对沙湖进行了4次取样调查，设置样点5个，调查分析沙湖主要水质因子的季节变化与时空分布，以及沙湖浮游动物的种类组成、密度、生物量、季节变化、优势种组成。

运用综合营养状态指数和评分法，结合浮游动物的生态学指标，评价沙湖的富营养状况；运用多样性指数分析沙湖浮游动物的多样性，运用聚类分析（Cluster analysis）和多维分析（Multidimensional scaling, MDS）分析沙湖浮游动物群落结构的分布格局；运用相关分析、多元逐步回归分析、通径分析和典范对应分析等多元分析方法研究沙湖浮游动物密度、生物量、种类数与水质因子之间的相互关系。

研究结果可为沙湖生态系统结构的研究提供本底资料，为沙湖富营养化治理、合理养殖、水环境评价及保护提供生物学依据和基础数据，本研究得到如下结果。

1、沙湖共鉴定出浮游动物35种，其中轮虫23种、枝角类8种、桡足类4种，年平均密度427ind./L，年平均生物量0.901mg/L。

浮游动物种类数时空变化明显，轮虫占绝对优势，各季节及采样点的种类组成均以轮虫为主。

沙湖浮游动物的常见种8种，优势种9种，均为轮虫，优势种半数为富营养湖泊的典型指示种。

各采样点Shannon-Wieaver物种多样性指数、Margalef物种丰富度指数、均匀度指数的年平均值差异很小，但季节变化较明显。

Shannon-Wieaver物种多样性指数冬季（2.855）最高，春季（1.696）最低。

Margalef物种丰富度指数春季（2.016）最高，秋季（1.686）最低。

均匀度的季节变化较为明显，由高到低依次为冬季、夏季、秋季、春季，冬季约为春季的2倍。

老渔场与十一队、进水口与湖中心的群落结构相似性较高，鸟岛与前两个类群间的浮游动物群落结构差异较大，主要表现为种类数量、密度及生物量上的差异。

2、利用综合富营养状态指数和评分法、各浮游动物类群的相对比例、浮游动物生物量、多样性指数及指示种对沙湖进行营养状态评价，沙湖已处于中度富营养状态。

3、沙湖浮游动物密度、生物量与叶绿素a含量、水温、总氮、总磷、高锰酸盐指数呈显著正相关，与透明度呈显著负相关，影响浮游动物密度的主要水质因子依次为叶绿素a含量、总氮、总磷，影响浮游动物生物量的主要水质因子依次为叶绿素a含量、总氮、透明度、高锰酸盐指数。

浮游动物的种类数与总氮呈显著正相关，影响浮游动物种类数的主要水质因子依次为高锰酸盐指数、总氮、叶绿素a含量、总磷、水温。

CCA排序结果将四个季节的5个采样点按季节划分为4组，透明度、水温和叶绿素、高锰酸盐指数、氮磷比分别为四个季节影响浮游动物的主要水质因子。

浮游动物与水质因子的CCA 排序结果将16种浮游动物分为3组，沙湖的多数优势种被分为一组，对有机物污染有较强的耐受力，主要受高锰酸盐指数、叶绿素a含量和水温的影响。

CCA排序还反映了沙湖不同浮游动物的生态分化现象，表现出它们在生态适应上的相似性。

关键词：沙湖，浮游动物，群落结构，水质因子，富营养化，多元分析AbstractThe five sample sites of Shahu Lake were surveyed in April 2008 (spring), July (summer), October (autumn), January 2009 (winter). The main water quality factors in spatial distribution and seasonal variation were analyzed, and the zooplankton species composition, density, biomass, seasonal variation, the dominant species composition were studied. The water eutrophication status of Shahu Lake was evaluated comprehensively by using integrated trophic status indices, graded approach and indicators of zooplankton ecology. The diversity indexs were used to analyze the diversity of zooplankton in Shahu Lake.Cluster analysis (Cluster analysis) and multidimensional analysis (Multidimensional scaling, MDS) were used to analysis the distribution pattern of zooplankton community structure in Shahu Lake. Multivariate analysis methods which included Correlation analysis, Multiple regression analysis, Path analysis and Canonical Correspondence Analysis were used to study the relationship between zooplankton density, biomass, species number and the water quality factors in Shahu Lake. The results could provide the background information for the study of the ecosystem structure in Shahu Lake, and provide biological references and basic data for the Shahu Lake eutrophication control, rational aquaculture, environmental assessment and protection. The results of this study are as follows.1.35 species of zooplankton were identified in Shahu, including 23 species of Rotifera, 8 species of Cladocera and 4 species of copepods .The year’s average density was 427ind./L and the year’s average biomass was 0.901mg/L. Spatial and temporal changes in the species composition of zooplankton were obvious. Rotifers was dominant in the species composition and was mainly species in each sampling points and the four seasons. There were 8 Common species and 9 dominant species of zooplankton in Shahu Lake, all of which were rotifers. Half of the dominant species were typical indicator species of eutrophic lakes.The annual average of Shannon-Wieaver species diversity index, Margalef species richness index and evenness index had little differences in each sampling point but had obvious differences in seasonal variation. Shannon-Wieaver species diversity index was the highest in winter (2.855) and the lowest in spring (1.696). Margalef species richness index in spring was the highest in spring (2.016) and the lowest in autumn (1.686). The seasonal variation of evenness index ranged as the order: winter, summer, fall, spring. The evenness index in spring was about 2 times more than in winter.Laoyuchang sample site and Shiyidui sample site were highly similar in the community structure of zooplankton and Jinshuikou sample site and Huzhongxin sample site were highly similar in the community structure of zooplankton. Niaodao sample site was quite different between the first and the second groups in the community structure and the differences were mainly about the number of species, density and biomass.2. The water eutrophication status of Shahu Lake was evaluate by integrated trophic status indices, graded approach, the relative proportions of each zooplankton groups, zooplankton biomass, diversity indices and indicator species. The result was that Shahu Lake has been moderate eutrophication.3.Chlorophyll a content, temperature, total nitrogen, total phosphorus, permanganate index were significant positive correlation with zooplankton density and biomass in Shahu Lake but the transparency was significant negative correlation with zooplankton density and biomass. The major water quality impact factors of zooplankton density were chlorophyll a concentration, total nitrogen, total phosphorus. The major water quality impact factors of zooplankton biomass were chlorophyll a content, total nitrogen, transparency and permanganate index. Total nitrogen was significant positive correlation with the number of species of zooplankton in Shahu. The major water quality impact factors of the number of zooplankton species were permanganate index, total nitrogen, chlorophyll a concentration, total phosphorus, water temperature.5 sample sites of the four seasons were divided into 4 groups by CCA. The major water quality impact factors of zooplankton were transparency, water temperature, chlorophyll, potassium permanganate index, nitrogen and phosphorus in four seasons.16 species of zooplankton were divided into 3 groups by CCA which adapted to different water quality factors. Having strong organic pollution tolerance, the most dominant species of Shahu Lake were divided into a group which were affected by potassium permanganate index, Chlorophyll a content and water temperature. The CCA results also reflected the polarization of zooplankton ecology and their similar in ecological adaptation.Keywords: Shahu Lake, zooplankton, community structure, water quality factors, eutrophication, multivariate analysis独创性声明本人声明所呈交的论文是我个人在导师指导下进行的研究工作及取得的研究成果。