Results
Almost one third taxa (28.95%) occurred at 50% of all sites or more in the HRB (Table 4). five species (Cryptomonas erosa, Chroomonas acuta , Cyclotella meneghiniana , Scenedesmus quadricauda ,Navicula cryptocephala ) occurred at more than 70% of the sites. Two Euglenophytes, two Chrysophytes and Pandorina morum occurred at less than 10% sites. Eighteen of 23 taxa were present in Dishui Lake during more than half of the sample dates (Table 4). Only five taxa had less than 50% occurrence (e.g. Carteria sp.,Amiphiprora sp., Cryptomonas ovata , Cyclotella sp.,Melosira varians ).