Predicting phytoplankton assemblages growth and estimating critical N: P ratios with experimental nutrient additions in a drinking water reservoir of central China

The purpose of this study was to evaluate the effects limiting nutrients and N: P ratios on growth phytoplankton. In study, we used nutrient enrichment bioassays (NEB), Multivariate analysis variance, regression analysis. results showed that affected change phytoplankton assemblages concentrations nitrogen phosphorous. During same period, response time input external similar. rates were not persistent. This is related differences in environmental conditions, dominant species composition, strategies. Different also had different mechanisms addition. effect preliminary experiment laboratory more significant than field experiment. Water temperature light important factors affecting variance phosphorus addition alone a stimulation nitrogen, especially for Synedra. But both most stimulating Cyanophyta Chlorophyta. maximum TN: TP = 19.87, promoted with 0.9 ∼ 13.59 mg/L TN 0.02 0.684 TP. When total summer greater 0.04 mg/L, possibility algal bloom will be greater. linear fitted chlorophyll well, equation as follows: Log10(Chl.a) 2.154 + 0.5103 × Log10(TP). binary Chl.a 33.84 1.769TN 123.9TP.