摘要：The study deals with water quality parameters affecting the composition, seasonal abundance and dominanceof phytoplankton in a wetland, Thol Bird Sanctuary, Central Gujarat, India. Hydrochemical parameters ofwater samples were analysed during September 2007 to August 2009. Monthly variation of water qualityparameters like temperature, pH, dissolved oxygen, total dissolved solids, total alkalinity, total hardness,chloride, phosphate, sulphate and nitrate were investigated during the study period. Nutrients like chloride,phosphate, sulphate and nitrate were found higher during summer and lower during monsoon months inboth the years. 102 phytoplankton taxa were identified of which Cyanophyta represented by 44 species,constituted the largest group, followed by Bacillariophyta by 25 species, Chlorophyta by 23 species andEuglenophyta by 10 species. Remarkable seasonal variation in mean density of Chlorophyta andBacillariophyta was observed during the study period. Chlorophyta members were present in reasonablenumbers throughout the study period, being most abundant in post monsoon and winters. Cyanophyta andEuglenophyta populations showed less seasonal variations except a noticeable increased in density ofEuglenophyta in summer 2009. The interrelationship between the hydrochemical properties and phytoplanktonassemblages and influence of water quality parameters were investigated by adopting statistical correlationcoefficient analysis and linear curves. The hierarchical cluster analysis was used to define biologically distinctregions within the wetland based on the composition of phytoplankton.
