THREE-DIMENSIONAL DISTRIBUTION OF LIGHT INTENSITY IN A TROPICAL RAIN FOREST OF WEST MALAYSIA

Abstract

YODA, Kyoji (Dep. Biol., Fac. Sci., Osaka City Univ., Osaka) Three-dimensional distribution of light intensity in a tropical rain forest of West Malaysia. Jap. J. Ecol. 24,247-254 (1974) The frequency distribution of relative light intensity at various height levels in an undisturbed rain forest (Pasoh Forest Reserve, Negri Sembilan, West Malaysia) was closely approximated by the lognorinal distribution, proving that the geometric mean was more reasonable than the arithmetical mean as the representative value of relative light intensity received by a certain height level under the leaf canopy. The mean value tended to decrease exponentially with decreasing height in each of the four layers between 0 m and 4 m, 4 m and 32 m, 32 m and 48 m and over 48 m above the ground. This suggested that the leaf area density was more or less homogeneously distributed in the vertical direction within each of the four layers. A diagrammatic representation of the three-dimensional distribution of relative light intensity in the forest canopy was prepard.