嘉陵江出口段三类水体蓝绿硅藻优势种变化机理  

The changes and mechanisms in dominant algae of Cyanophyta, Chlorophyta and Bacillariophyta during the eutrophication vulnerable period in the outlet area of Jialing River in China

作　　者：郭蔚华[1] 李楠[1] 张智[1] 曾晓岚[1] 

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,重庆400045

出　　处：《生态环境学报》2009年第1期51-56,共6页Ecology and Environmental Sciences

基　　金：国家"十一五"科技支撑计划(2006BAJ01A06-3)

摘　　要：三峡水库的河流型、过渡型、湖泊型水体中后两者为富营养化敏感水体,为认识富营养化敏感时期嘉陵江出口段三类水体蓝藻（Cyanophyta）、绿藻（Chlorophyta）、硅藻（Bacillariophyta）优势种变化及机理,2007年9月至2008年8月进行了三种藻类的现场调查分析。结果表明,在3-7月份,总藻种数为52种,占全年种数的66.5%,平均密度43.76×104个·L-1,为全年中最高,因此3-7月为富营养化敏感期;优势藻种类变化为河流型蓝、绿、硅藻分别为6、4、9种,过渡型的蓝、绿、硅藻分别为4、5、4种,湖泊型的蓝、绿、硅藻分别为6、5、3种;蓝、绿、硅各优势藻的平均优势度在2.5m·s-1为0.11,2.0m·s-1为0.11,1.5m·s-1为0.10,0.05~0.2m·s-1为0.07,〈0.05m·s-1为0.06。分析认为,蓝、绿、硅优藻种数变化与流速有关,优势硅藻种数与流速正相关,优势蓝、绿藻数与流速反相关;具有硅壳的硅藻需要借助流速浮动进行光合作用,适宜0.05~2.5m·s-1水体;大型硅藻可能通过进化中的硅壳薄化来适应一定流速的水体;蓝藻、绿藻沉降系数小,有的具有气囊或鞭毛,因而易浮动进行光合作用,适宜0.2m·s-1以下的水体;优势蓝、绿、硅藻的平均优势度与优势藻多样性负相关。随着嘉陵江出口段采样点的流速逐渐减小,优势蓝、绿、硅藻的平均优势度逐渐变小,而优势藻多样性逐渐增大。The Three Gorges Reservoir （TGR） created by the damming of the Yangtze River. It is a complex of three water body types： river type, river-lake type and lake type. The first two types are sensitive to eutrophic water environments. In order to recognize the changes and mechanisms in the dominant algae composition of Cyanophyta, Chlorophyta and Bacillariophyta in the outlet of Three Gorges reservoir during the vulnerable period, this research was carried out in the outlet area of Jialing River from September 2007 to August 2008. The results indicated that, from March to July, there were totally 52 algae representing 66.5% of total species in one year and at the same time the average density was up to 43.76×104 cells·L-1, which reached the maximum of one year, therefore, the time segment from March to July was the eutrophication vulnerable period. The changes of the dominant algae composition of Cyanophyta, Chlorophyta and Bacillariophyta were as follows： in the river type water,there were 6 kinds of Cyanophyta, 4 kinds of Chlorophyta and 9 kinds of Bacillariophyta, respectively,in the river-lake type water, the composition was 4 Cyanophyta, 5 Chlorophyta and 4 Bacillariophyta, respectively,in the lake type water, the composition was 6 Cyanophyta, 5 Chlorophyta and 3 Bacillariophyta and the mean dominances of the three algae were：0.11 at a velocity of 2.5 m·s-1, 0.11 at a velocity of 2.0 m·s-1, 0.10 at a velocity of 1.5 m·s-1, 0.07 at a velocity of 0.05～0.2 m·s-1 and 0.06 below the velocity of 0.05 m·s-1. By the analysis, the changes in dominant species of Cyanophyta, Chlorophyta and Bacillariophyta were related to the velocity of water with the positive correlation between the dominant species of Bacillariophyta and the velocity the negative correlation between the dominant species of Cyanophyta, Chlorophyta and the velocity. The mechanisms showed the floating with a certain velocity might be beneficial to the photosynthesis process of the Bacillariophyta with silica shell and the appropriate vel

关 键 词：变化机理 优势藻种 蓝藻 绿藻 硅藻 嘉陵江 

分 类 号：Q948[生物学—植物学]