THE EFFECT OF IRRADIANCE ON THE GROWTH OF DIFFERENT FORMS OF FRESHWATER DIATOMS: IMPLICATIONS FOR SUCCESSION IN ATTACHED DIATOM COMMUNITIES

Abstract

The growth rates of 12 strains of attached freshwater diatoms were examined as a function of irradiance. The results were used to determine physiological parameters in the growth-irradiance relationships. Values of G_max (maximum growth rate) and I _k (irradiance at half of G_max ) correlated with successional phase. The development of attached diatom communities appears to proceed from high irradiance species to low irradiance species that appear later in the successional sequence. Thus, efficiency of light use is linked to successional strategy, as has been documented for terrestrial plants.