苏州平原河网区浅水湖泊冬夏季浮游植物群落与环境因子的典范对应分析

2005年12月和2006年6月对苏州平原河网区57个浅水湖泊的浮游植物群落进行了调查，共检出浮游植物8门62属73种，浮游植物主要由绿藻、硅藻和蓝藻组成.冬季浮游植物平均丰度为254.88×10⁴cells·L^-1，硅藻门丰度占总丰度的62.3％；夏季浮游植物平均丰度为2 704.28×10⁴cells·L^-1，蓝藻门丰度达93.5％.运用典范对应分析(canonical correspondence analysis, CCA)对调查范围内的57个样点62属浮游植物与11个环境因子关系进行研究.结果表明，水温、高锰酸盐指数、NO^-₃-N和TN是影响苏州平原河网区浅水湖泊浮游植物群落分布的主要环境因子，在冬季，pH、NH⁺₄-N及TP也是主要的影响因子；浮游植物中硅藻对环境变化具有较强的适应性，绿藻能耐受较高的高锰酸盐指数、氮磷营养盐和TOC浓度，而蓝藻对环境因子的响应有待进一步的研究.

Canonical Correspondence Analysis Between Phytoplankton Community and Environmental Factors in Winter and Summer in Shallow Lakes of Plain River Network Areas, Suzhou

Field investigations on the phytoplankton community were carried out in December 2005 and June 2006 in shallow lakes of plain river network areas, Suzhou City. Results show that there are 73 species, 62 genus, 8 phylum phytoplankton, which is mainly composed of the Chlorophyta, Bacillariophyta and Cyanophyta. In winter, the average phytoplankton abundance is 254.88×10⁴cells·L^-1, and the Bacillariophyta abundance accounts for 62.3% of the total. While in summer, the average phytoplankton abundance is 2 704.28×10⁴cells·L^-1, and the Cyanophyta abundance accounts for 93.5%. The relationship between 62 genus of phytoplankton and 11 environmental factors from 57 sampling sites in research area was studied by Canonical Correspondence Analysis. It suggests that water temperature, permanganate indexes, nitrate nitrogen and total nitrogen are the main environmental factors correlated with the distribution of phytoplankton community. And in winter, pH, ammonia nitrogen and total phosphorus are also the main environmental factors. Furthermore, the Bacillariophyta has higher adaptability to the changeable environment. The Chlorophyta can tolerate higher concentration of permanganate indexes, phosphorus nutrients, nitrogen nutrients and total organic carbon, whereas the response of Cyanophyta to environmental factors needs further research.