摘要：The effects of density on the growth rate and survival of individual plants as well as changes in population structure and self-thinning were experimentally evaluated in Melastoma malabathricum at five densities (19098, 76394, 152788, 229183 and 458365 seeds m-2). The biomass (dry weight) of root, stem and leaf was measured for seven times after drying from the 18 to 162th days after planting. It was applied at 20 day intervals. The relationship between the total dry matter weights per plant and plant densities of survivors for populations of Melastoma malabathricum showed that each population will start to thin along a line of slope from -3.7 to -1.2 until it reaches the maximum standing crop. Mortality during the phase of self-thinning is largely among individuals suppressed by the ensuing growth of neighbours, resulting in increased shading within the canopies of neighbouring plants. The total dry matter (m-2) was constant over a wide range of densities because individual plant displayed density-dependent reduction in growth rate and hence in individual plant size, in particular, because the reductions in mean plant weight compensated exactly for increase in density.
