滴水湖浮游植物时空分布动态及其影响因子

为探究滴水湖水系浮游植物群落状况及其与环境因子的关系，在滴水湖出海闸、湖心及与外河相通处共设置8处样点，于2011年1~12月，逐月对滴水湖浮游植物群落和水质状况进行调查。期间共鉴定浮游植物6门61属128种，绿藻门和硅藻门种数之和达检出种总数的70%，全湖以隐藻门的尖尾蓝隐藻、绿藻门的小球藻、斯诺衣藻为全年主要优势种。优势种类以3月、4月和11月份最多且优势种间数量差别不大，显示春秋季较夏冬季群落结构复杂。浮游植物Shannon Wiener、Margalef和Pielou指数分别为123±046、397±066、083±029。多样性指数显示湖区水体位于轻污-中污水平，3种指数均表现夏冬季较春秋季低。单因素方差分析显示，浮游植物种类数和个体数在月间差异极显著，而空间上均无显著差异。浮游植物平均密度为742×106 ind./L，与水温呈极显著相关，对浮游植物与环境因子的典范对应分析（CCA）表明，除温度外，总磷浓度是影响湖区常见浮游植物数量的重要因素

DYNAMICS OF SPATIAL AND TEMPORAL DISTRIBUTION OF PHYTOPLANKTON AND RELATED AFFECTING FACTORS IN THE DISHUI LAKE

In order to understand the status of phytoplankton community in the Dishui Lake and its relationship with water quality,8 sampling sites were investigated monthly from January to December in 2011,including the lake’s center,sea sluice and water inlets.A total of 61 genera and 128 species of phytoplankton were identified,among which,above 70% are Bacillariophyta and Chlorophyta.The dominant species of the year were Chroomonas acuta,Chlorella vulgaris,and Chamydomonas snowiae.There were most dominant species in March,April and Novermber,which indicated that the community structure might be more complicated in spring and autumn than that in the other 2 seasons.Shannon Wiener Index(H’),Margalef index (d) and Pielou Evenness Index(J) were 123±046,397±066,083±029 respectively.The diversity index showed that most of the samplings were in the status of light and moderate pollution.All of the 3 index were higher in spring and autumn.One way analysis of variance demonstrated that both of phytoplankton species and quantities had an extremely significant difference among months,while no significant difference among the sampling sites.The total phytoplankton density was 742×106 ind./L, and had a strong relevance with water temperature.Canonical correspondence analysis (CCA) showed that,the densities of main phytoplankton species of the Dishui Lake were greatly affected by TP and pH,besides water temperature