长江干流安庆段浮游植物群落结构特征

为了解长江干流安庆段浮游植物群落结构特征,分别于2015年4月(春季)、7月(夏季)和9月(秋季)对长江干流安庆段浮游植物进行了调查。结果显示:本次调查共检出浮游植物5门22科33属54种(含变种)。以硅藻门种类最多,占总种数的46.30%;其次是蓝藻门和绿藻门,分别占24.07%和22.22%;黄藻门和甲藻门的种类相对较少,占5.56%和1.85%。优势种为蓝藻门的小颤藻(Oscillatoria tenuis)、极大螺旋藻(Spirulina maxima)、湖沼色球藻(Chroococcus minutus),绿藻门的小球藻(Chlorella vulgaris)、集星藻(Actinastrum hantzschii)以及硅藻门的尖针杆藻(Synedra acus)。浮游植物密度为1.228×10~4~33.002×10~4ind./L,均值为9.453×10~4ind./L;生物量为0.005~0.512 mg/L,均值为0.157 mg/L。密度和生物量最高值均出现在皖河口采样断面(7月)、最低值均出现在杨家套采样断面(4月)。研究结果表明:浮游植物密度和生物量在空间分布上差异均不显著,季节变化上则均表现出显著性差异。利用Shannon-Wiener指数和Pielou均匀度指数分析浮游植物群落结构特征,Shannon-Wiener指数变化范围为0.918~3.147,均值为2.539;Pielou均匀度指数变化范围为0.796~1.000,均值为0.893。Shannon-Wiener指数在空间分布和季节间均无显著性差异;Pielou均匀度指数在空间分布上无显著性差异,但在季节间变化上则表现出显著性差异。浮游植物多样性指数结果表明长江干流安庆段水质状况介于清洁型/β-中污型。

The characteristic of phytoplankton community structure in Anqing section of the Yangtze River

The phytoplankton survey was carried out in Anqing section of the Yangtze River in April、July and September 2015 in order to understand the characteristic of phytoplankton community structure.The results showed that the obtained phytoplankton belonged to 5 phyla,22 families,33 genuses and 54 species (including varieties).Bacillariophyta was the main compositions of phytoplankton community,which accounted for 46.30% of the total number of algae species.Secondly,Cyanophyta and Chlorophyta accounted for 24.07% and 22.22%,respectively.The species of Xanthophyta and Pyrrhophyta were less,which accounted for 5.56% and 1.85%,respectively.Dominant species mainly included Oscillatoria tenuis、Chlorella vulgaris、Spirulina maxima、Chroococcus minutus、Actinastrum hantzschiiand Synedra acus.Phytoplankton density ranged from 1.228×104 ind./L to 33.002×104 ind./L,with an average of 9.453×104 ind./L;biomass was 0.005~0.512 mg/L,with an average of 0.157 mg/L.The highest and lowest sampling were pointed(July) and (April).Result showed that both Phytoplankton density and biomass did not change significantly in spatial distribution,but showed extremely significant difference between the seasons.The Shannon-Wiener index and Pielou evenness index were used to analyze the characteristic of phytoplankton community structure.Shannon-Wiener index ranged from 0.918 to 3.147,with an average of 2.539;Pielou evenness index ranged from 0.796 to 1.000,with an average of 0.893.Shannon-Wiener index did not change significantly both in spatial distribution and between the seasons;Pielou evenness index did not change significantly in spatial distribution,but extremely significant difference between the seasons.It was found that the water body of Anqing section of the Yangtze River belonged to clean/-ms type compared the phytoplankton biodiversity index.