Abstract
The relation between the leaf area index (L.A.I.) of artificial communities of cotton plants and their rates of dark respiration and of net photosynthesis at three light intensities was examined. The L.A.I. was varied by the removal of successive layers of leaves, working from the base of the canopy upwards. Experiments were carried out at 20, 30, and 40°0 to vary the relative magnitudes of respiration and photosynthesis.