On the Establishment of the Vertical Distribution of Photosynthetic System in a Plant Community

1. Concerning the vertical light distribution and density-distribution of leaf or phytoplankton, theoretical equations have been formulated [Equations (5), (6) and their simplified forms, Equations (7), (8)], on an assumption that such density-distribution is formed proportionally to the productivity of leaves or phytoplankton. 2. Theoretical curves thus obtained are practically of the same type as the curves obtained in a phytoplankton community in stagnation period of waters and they also accord well with the characteristic of the lower part of leaf distribution in the land plant community. 3. In order experimentally to prove these theoretical equations, seven or twelve shallow glass dishes were piled up, each of which contained 200ml. of Chlorella ellipsoidea suspension in the same concentration. The development of vertical Chlorella distribution (Fig. 3) accorded considerably well with that calculated with Equation (8) (Fig. 2). 4. By referring to the common growth form of land plants (Fig. 4), theoretical Equation (6) or (8) has been revised as Equation (10), which well expresses the characteristics of the vertical leaf distribution of land plant community (Fig. 5). 5. Interrelationships between productive structure and productivity of plant community, and between 'action' and 'reaction' were interpreted, based upon the theoretical equations.