Problems in Modelling the Photosynthesis-Light Relationship for Phytoplankton

Abstract

Is there a best model for the algal photosynthesis-light relationship? Jassby and Platt''s (1976) verdict favoring the hyperbolic tangent model is reassessed, the theoretical basis of model fitting is discussed and a warning is given against equating model parameters with real physiological efficiencies or rates. To avoid bias, models should be fitted without transforming data and parameters estimated simultaneously and independently. Use of such a method shows that the fit of several models cannot be distinguished from that of the hyperbolic tangent. One of these models is that of Smith (1936) and Talling (1957) and the continued use of this model when there is no photoinhibition is commended on the grounds of relative computational simplicity and wide usage.