Transient photosynthetic responses of nitrogen limited macroalgae to nitrogen addition

Abstract

The effect on photosynthesis of nitrogen addition to nitrogen limited phytoplankton was investigated in several species of algae. Addition of a nitrogen source induced suppression of carbon fixation in some species but not in others. The photosynthetic suppression response upon limiting nutrient addition is taxonomically widespread but appears to be species or strain specific. Discrepancies in previous reports are ascribed to differential phytoplankton responses and not to methodological differences. The physiological and ecological significances of the suppression phenomenon are considered.