| Phytoplankton assemblages were sampled in September, 2010, November, April and July, 2011 in main rivers of Jiangyin city of Taihu basin.141 species / genera belonging to 7 phyla were identified.The results indicated higher species richness and standing crop of phytoplankton during summer and autumn than during winter and spring.The dominant algal group during winter and spring were centric diatom (Cyclotella meneghiniana, Aulacoseira granulata), Cryptophyta (Cryptomonas erosa), Euglenophyta (Euglena spp.) and Chlorophyta (Chlamydomonas spp.and Oocystis spp.).The community during summer and autumn was dominated by Cyanobacteria (Oscillatoria princes, Planktothrix agardhii) and diatom (C.meneghiniana).The seasonal variation among north-south rivers (Xicheng river, Baiqugang river and Zhangjiagang river) was much severer than that among east-west rivers (Yingtian river, Xiheng river and Dongheng river). It indicated that main rivers were in α, β- type moderate pollution by saprobic indicator. |
