INTERACTION BETWEEN GLOBAL CLIMATE-CHANGE AND THE PHYSIOLOGICAL-RESPONSES OF ALGAE

The radiation climate as one essential factor influencing phytoplankto n primary production will likely change in near future due to the incr ease of UV-A/B radiation and to stronger vertical mixing. The emission of dimethylsulphide (DMS) from dimethylsulphonium propionate (DMSP) i nfluences the radiation climate due to its impact on cloud formation T he diatom Phaeodactylum tricornutum had a high acclimation ability to radiation stress resulting in a rapid recovery from stress induced los ses in photosynthetic efficiency. In this case the primary production was not strongly impaired, and UV-B impaired photosynthesis by a mecha nism different from that under excess PAR. The DMSP content of Prymnes ium parvum was independent of irradiance and nitrogen supply. Total DM SP production of Prymnesium, however, was closely related to the age o f the cells which was reduced under high irradiance.