In this paper, the amount of photosynthesis accomplished by a canopy of leaves is predicted from the properties of individual leaves. Theories are developed for the penetration of direct and diffuse sunlight through a foliage composed of many layers of leaves, each having known orientation, area, reflection and transmission characteristics. From this, the illumination of each leaf at a particular time of day (sun elevation) and thus its photosynthesis, is determined. Hourly observations are summed for estimates of daily photosynthesis by plant communities.
