Correlations between the volume of dominant periphytic algae species and the water quality parameters in Gufu River

Changes in volume of periphytic algae dominant species in Gufu River of Three Gorges Reservoir Area were studied and the main parameters of water quality influencing the change were explored, in order to provide an evidence for the quality assessment of river water. Periphytic algae and water quality samples were collected eleven times from December 2010 to February, 2012. A total of 197 species were identified from the periphytic algae samples, and ten water quality factors were measured. The species of which Mcnaughton dominance-index(Y) was large than 0.02 were chosen as the dominant species and their volumes were calculated. The analysis of the volume changes of these dominant species(thirty species) during various months by using the Principal Component Analysis(PCA) showed that Bacillariophyta were more sensitive to the seasonal variations. The analysis of the relationship between the water quality parameters and the volume of dominant species by Canonical Correlation Analysis(CCA) demonstrated that the sequencing of the correlations between the water quality and algae volumes were: DO NH4+-N chlorophyll a p H NO3--N TP Tem. TN TOC COD. Monte Carlo significance test showed that the volume of dominant species was most influenced by COD and, and less by chlorophyll a, p H and. The results suggest that the variations of the volume of Bacillariophyta could partly reflect the variation of the concentrations of COD, chlorophyll a, p H and in Gufu River.