摘 要 ：本文对勐腊县补蚌望天树(Parashorea chinensis Wang Hsie）群进行了从种于开始各龄级生长动态的分析。在自然状况下，望天树种群平均每3—4年出现一次旺盛生殖期。处于该期的望天树，胸径30—40厘米，年龄60—80年，每株可产生种子2000—6000颗。种于主要散布在离树体15—30米的环形地带内。种子萌发率68．9％，当年能发育成幼苗的种子占22.35%。幼苗中仅0.72%进入幼树阶段成为望天树种群的预备种群。能发展为稳定的上层构造种群植株的幼苗只有0.023%，大约需要种子20000颗。由于种子的集聚型散布以及各营养生长期中高的死亡率，望天树种群难于扩张。
Abstract:In Parashorea chinensis population there is a great breeding period at intervals of each 3-4 years. During this period the Parashorea can produce about 2000-6000 seeds per tree which is about 30-40 cm in bdh and about 60-80 years old. The seed dispersal range is very limited in a circle of 15-30 meters far from the mother tree. The germination capacity is 68.90 and seedling survival rate 22.35. There are about 0.72 of seedlings growing up, but less than 0.023 of seedlings entering the highest storey in population‘s vertical strata of the Parashorea. It means that 20 000 seeds are needed for one tree developing into the highest storey. The population of the Parashorea is very difficult to spread because of the seeds concen-trated on a limited range in high density and the high mortality existed in every developing stage of the age clases.