防城港海域浮游植物群落结构及其环境适应性

于2014年9月~2015年8月按季度对防城港海域浮游植物进行4个航次的综合调查,结果显示,该海域共鉴定出浮游植物130种,其中硅藻门106种、甲藻门19种、金藻门2种、蓝藻门2种和绿藻门1种。浮游植物各站位的丰度为1.50×10~6~797.18×10~6个·m~(-3),均值为122.91×10~6个·m~(-3),且季节差异极显著(P0.01),呈秋季夏季冬季春季的特征。群落Shannon-Wiener多样性指数为0.37~4.00,均值为2.60,处于轻度污染水平。该海域浮游植物依种类组成的相似性可划分为10 m以浅和10~20 m水深的2个类群(P=0.001)。冗余分析表明,4个季度中,所调查的8个环境因子共解释了57.51%~72.65%浮游植物丰度的空间变化;水深、水温、溶解氧(DO)和磷酸盐浓度是影响防城港海域浮游植物群落格局的主要环境因子且各因子影响程度存在季节差异。

Phytoplankton community structure and its environmental adaptation in Fangcheng coastal waters

The seasonal surveys on phytoplankton community and their environmental variables were conducted in Fangcheng coastal waters from September 2014 to August 2015.A total of 130 species of phytoplankton were identified (106 species of Bacillariophyta,19 species of Pyrrhophyta,2 species of Chrysophyta,2 species of Cyanophyta and 1 species of Chlorophyta).The abundance of phytoplankton ranged from 1.50×106 cells·m-3 to 797.18×106 cells·m-3 (average:122.91×106 cells·m-3) and had significant difference among seasons(P<0.01)in a descending order of autumn>summer >winter >spring.The Shannon-Wiener diversity index ranged from 0.37 to 4.00 with an average of 2.60,indicating slight environmental pollution.The cluster analysis of species similarity between sites has found a coastal group with water depth of less than 10 m and a middle group with water depth between 10 m and 20 m (P=0.001).The result of redundancy analysis (RDA) shows that the eight environmental factors explained 57.51%~72.65% spatial variation of phytoplankton abundance.Depth,water temperature,dissolved oxygen and concentrations of phosphates were the dominant factors affecting the phytoplankton community in Fangcheng coastal waters and their importance varied with seasons.