湖光岩玛珥湖的浮游植物

THE PHYTOPLANKTON OF THE HUGUANGYAN MAAR LAKE

本文对广东省湛江市湖光岩玛珥湖的浮游植物进行了周年的调查和分析,结果共检出浮游植物99属260种(包括变种和变型):春季119种,夏季121种,秋季150种,冬季122种,其中蓝藻门20属43种,占种类数的16.5%;硅藻门20属79种,占种类数的30.4%;绿藻门49属117种,占种类数的45%;甲藻门2属8种,占种类数的3.1%;裸藻门2属2种,占种类数的0.8%;金藻门2属6种,占种类数的2.3%;黄藻门3属4种,占种类数的1.5%;红藻门1属1种,占种类数的0.4%。全年广布种有40种:蓝藻门15种,硅藻门6种,绿藻门14种,甲藻门3种,金藻门和黄藻门各1种。各两季节间的共有种数在57—78种,Jaccard种类相似性指数范围在0.28—0.42。优势种(Y>0.02)共有29种:春季8种、夏季16种、秋季13种、冬季11种,分别隶属于蓝藻门13种,绿藻门8种,硅藻门8种,其中Chroococcus m inor、M icrocystis flos-aquae、Pleurocapsa fuliginosa、Chlorella vulgaris为全年广布优势种。在春、夏、秋3季以蓝藻的优势种类居多,而在冬季则以硅藻的优势种类居多。细胞丰度在6.3×104—56.1×104ind/L,春季最高,冬季次之,夏季最低。多样性指数平均为4.53,均匀度平均为0.65,其排序都为冬季>秋季>夏季>春季,物种非常丰富。浮游植物群落中存在着os、βm、αm的优势种群,其群落结构具有典型的亚热带特征。从浮游植物吸收N、P的配比分析,P成为全年唯一的营养限制因子,但从N、P的绝对值看,N和P都是全年的营养限制因子。综合分析结果,湖光岩玛珥湖水质营养类型属于亚热带贫营养型。

Annual investigations on the community of phytoplankton and physicochemical factors were carried out in the Huguangyan Maar Lake,Zhanjiang,Guangdong Province of China.The results showed that a total of 260 species of the phytoplankton（including variety and form） belonged to 99 genus were found,with 119 species emerging in spring,121 species in summer,150 species in autumn and 122 species in winter.Among which,20 genus including 43 species belonged to Cyanophyta,accounting for 16.5% of all species,20 genus including 79 species were Bacillariophyta,accounting for 30.4%,49 genus including 117 species were Chlorophyta,accounting for 45%,2 genus including 8 species were Pyrrophyta,accounting for 3.1%,2 genus including 2 species were Euglenophyta,accounting for 0.8%,2 genus including 6 species were Chrysophyta,accounting for 2.3%,3 genus including 4 species were Xanthophyta,accounting for 1.5%,and 1 genus including 1 species was Rhodophyta,accounting for 0.4%.There were 40 widespread species in all year,with 15 species being Cyanophyta,6 species being Bacillariophyta,14 species being Chlorophyta,3 species being Pyrrophyta,and both species being Chrysophyta and Xanthophyta respectively.There were mutual 57—78 species in each assembly of both seasons while Jaccard index was 0.28—0.42 dominant species（Y〉0.02） presented through the year and belonged to Cyanophyta（13 species）,Chlorophyta（8 species） and Bacillariophyta（8 species） respectively,with 8 species in spring,16 species in summer,13 species in autumn and 11 species in winter,in which Chroococcus minor,Microcystis flos-aquae,Pleurocapsa fuliginosa and Chlorella vulgaris were annually widespread species.The most dominant species were Cyanophyta in spring,summer and autumn,but the most ones were Bacillariophyta in winter.The average cell abundance of phytoplankton ranged from 6.3×104ind/L to 56.1×104ind/L,with the maximum in spring,the second in winter and the minimum in summer.The averages of Shannon-weaver index and evenness were 4.53 and 0.65 respectively,with the maximum in winter,followed by autumn,summer and spring;the species were very abundant.There were the dominant populations of os,βm and αm in the community of phytoplankton,accompanied by typically subtropical character.The element P was the only limiting factor of nutrition in whole year according to the ratio of N/P,but both N and P were limiting factors of nutrition based on the absolute value of N and P.The comprehensive analysis indicated that the nutritional types of water quality belonged to subtropical oligotrophic types in this lake.