Physiological responses of phytoplankton to natural light regimes

Physiological responses to changes in light intensity and quality are known to occur on many time scales. The mechanisms controlling the responses on short time scales (such as the ‘flicker’ effect and state transitions), medium rime scales (did changes and light-shade adaptation), and long time scales (species succession) are poorly understood. On the basis of present information, however, it is suggested that models of the effects of vertical mising on primary production could be improved by incorporating more basic information about some of the shorter time-scale responses.