Photosynthetic enhancement at high light intensities.

Enhancement of photosynthetic oxygen evolution by Chlorella pyrenoidosa (211-8b) decreased almost linearly as the rate of photosynthesis was increased. The observed decrease was predicted most accurately by a model assuming exponential rate versus intensity curves as opposed to a model assuming hyperbolic light curves. The decrease in enhancement was not changed significantly upon changing from 0.03% to 5% carbon dioxide.