COMPARISON OF DECOMPOSITION RATES OF SEVERAL TREE LEAF LITTER IN A TROPICAL FOREST IN THE NORTH-EAST THAILAND

Abstract

The decomposition of leaf litter of 7 tree species was studied over 6 months from March 1980 to September 1980 in a tropical forest in the north-east Thailand. Besides the decomposition study, the feeding activities and population densities of soil arthropods were studied in the same study area. Decomposition rates were expressed by a constant of a negative exponential model and varied from 0.0422 to 0.2308 month^-1 according to the species. The most rapid rate was that of Croton oblongifolium which lost about 60% of initial weight during the 6 months and the most slow rate was that of Diospyros castanea which lost only 22% of initial weight during the period. Decomposability was significantly correlated with the leaf thickness and field observations suggested that thicker and tougher leaves disappear most slowly. The decomposition rates estimated were compared with other similar studies in tropical forests and the decomposition rates of leaf litter were rather slower in this study area.