The Effects of Light Intensity on the Growth Rates of Green Algae.

Abstract

The growth characteristics of Chlorella pyrenoidosa, van Niel strain, Chlorella pyrenoidosa, high-temperature strain 7-11-05, Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardti were studied under light intensities up to 10,000 foot candles. Saturating and injurious light intensities and growth rates in light-dependent and light-independent regions of the light-intensity curves were determined. Changes in the slopes of the growth rate curves in the light-dependent range, with increase in light intensity, were described in all studied strains and were found to be consistant with the observations of earlier investigators. The validity of comparisons of the data with those of other workers was discussed, particularly with regard to differences in source and geometry of illumination.