Abstract

Effects of temperature on phytoplankton recruitment and variations in phytoplankton community were studied by using hiemal sediment from Taihu Lake and performing a simulation experiment. Sediment samples were cultured in filtered lake water with elevated temperatures. Recruitment patterns and photosynthetic capacity of cyanobacteria, chlorophytes and diatoms were recorded, respectively. Results showed that recruitment of chlorophytes and diatoms was observed above 9°C, but recruitment of cyanobacteria was not evidently detected until 12.5°C. Chlorophytes dominated the phytoplankton community at 12.5 and 16°C, subsequently cyanobacteria established dominance above 19.5°C. In this study, algal cells remained weak photochemical vitality at lower temperatures before recruitment, which reactivated and increased gradually with elevated temperatures.

Key words: Recruitment, temperature threshold, cyanobacteria, blooms, Taihu Lake, phytoplankton community.