Abstract: The distribution patterns of Cyanophyta in two subtropical reservoirs,Xinfengjiang Reservoir and Qieyeshi Reservoir, in Guangdong Province were investigated bimonthly in 2004. A total of 18 genera were identified, and most of them were filamentous and colonial. The most common genera were Pseudanabaena, Limnothrix, Microcystis and Dactylococcopsis, and the Cyanophyta abundance was 4-249 cells·ml^-1 in Xinfengjiang Reservoir and 1911-114228 cells·ml^-1 in Qieyeshi Reservoir. In eutrophic reservoir, Qiyeshi Reservoir, the abundance of Cyanophyta was several orders higher than that in oligotrophic reservoir, Xinfengjiang Reservoir. In both of the reservoirs, the maximum abundance occurred in summer, and temperature was the possible factor controlling the seasonal variation of Cyanophyta abundance. In Xinfengjiang Reservoir, Microcystis was one of the dominant Cyanophyta species, which contributed 35%-97% of the total abundance, and its maximum abundance was found in summer. In Qiyeshi Reservoir,Microcystis abundance was one order higher than that in Xinfengjiang Reservoir, but its relative abundance was lower than 3%.Pseudanabaena and Limnothrix were the dominant Cyanophyta species, and contributed more than 50% of the total Cyanophyta abundance most of the time. The stability of water body and the underwater light condition driven by water transparence seemed to be the key factors inducing Cyanophyta dominated by different ecotypes of species in the two reservoirs.

Key words: Erythroneura sudra, Erigonidum graminicola, Three-dimentional distribution pattern, Time series dynamics