Phytoplankton Community Composition and Biodiversity Variation in Laohutan Reservoir
Laohutan Reservoir locates in Huzhou,Zhejiang.Phytoplankton community structure was investigated and analyzed to explain the ecological characters of Laohutan Reservior from June,2011 to May,2012.In the period,a toal of 8 phylum 60 families 96 species were identified,in which,there were 46 species of Chlorophyta,21 species of Bacillariophyta,16 species of Cyanophyta,4 species of Pyrrhophyta,3 species of Cryptophyta,3 species of Euglenophyta,3 species of Xanthophyta.Green algae was dominance in the species composition.Seasonal succession of the dominate species of phytoplank ton was significant different.In spring,the dominate species present to be the Diatom-Blue algae type,and the most species was Achnanthes exigua;and in summer it present to be the Diatom type,the most species was Synedra acusvar;then in autumn,the dominate species present to be the Green-Blue algae type,the most species was Anabaenopsis sp.;fanally in winter the algae type was return to Diatom type,the most dominate species was Melosira granulate.The analysis of biodiversity index showed that,the annual average of Shannon-Wiener Index was 1.87,which indicate the nutrition type of Laohutan Re servior was Mesotropher.