| Abstract: | Fertilization experiments in mesocosms of 1 … 2,000 1 containing up to 0.32 mg/l P and 1.7 mg/l N in summer and in winter did not show any significant changes of the hydrochemical conditions and in the bacterio-plankton. CO2-assimilation (14-C method) is reduced by circa 10= by nutrient doses, whereas the chlorophyll concentration increases significantly due to addition of P and N at the same time in summer, a decrease taking place in winter. The different courses of development are connected with different reactions of individual species of phytoplankton. |
