Niche differentiation of Dipterocarpaceae and Fagaceae-a study in Asian rain forest-

1. 在52 ha的样地上，分析了73种和9个亚种的分布，其中73%的种具有随地形变化的分布格局。这一事实表明，地形生态位的分化可能有助于双龙心科植物在样地的共存。对非双果分类单元也进行了同样的分析，得到了相同的结果。利用航拍资料和土地调查资料估算了林隙形成率和恢复率。有两种类型的裂缝：一种是由大雨引起的滑坡形成的，另一种是由树木倒下形成的。两种林隙形成的频率和恢复过程不同，通过两种林隙形成过程提供了不同的更新生态位。更新生态位的多样性对树种共存的贡献将在不久的将来进行分析。对两种旱蝗属植物进行了遗传分析。两种植物在52 ha的种群间表现出较高的遗传分化，表明该物种具有较高的遗传多样性。相反，两个同域物种之间的遗传距离很小，表明两个物种的生态位分化和物种形成是最近发生的。泰国山地雨林壳斗科植物研究建立了15 hapiot的研究样地，完成了7.5 ha的树木普查和3.0 ha的鉴定。还绘制了3.0 ha区域的缺口。初步资料分析表明，许多壳斗科植物具有与特殊地形或间隙有关的分布格局。壳斗科植物的生态位分化将在不久的将来进行定性分析。

1. Research on Dipterocarpaceae at a tropical lowland rainforest of SarawakDistribution of 73 species and 9 subspecies of dipterocarps were analyzed in a 52 ha plot, and 73% of the examined species had distribution pattern depending on the topography. The fact suggest tht the topographical niche differentiation might contribute to enable the coexistence of dipterocarps in the plot. This analysis was also made for non-dipterocarp taxon, and same results were achieved. Canopy gap formation rate and recovery rate were estimated by using aerial photographs and by the land survey. There werer two types of gaps : one type was formed by the land slide associated with heavy rain and the other was formed by the tree falls. Two types of gap formation differed the frequency and recovery process and the various regeneration niches for the tree species were provided through two gap formation process. The contribution of the diversity of regeneration niche to the coexistence of tree species will be analyzed near future. Genetic analyzes were made for two species of genus Dryobalanops. Both of the species showed high genetic differentiation among the local populations located in 52 ha, indicating the high genetic diversity of the species. On the contrary, genetic distance between two sympatric species was quite small indicating niche differentiation and speciation of the two species had occurred recently.2. Research on Fagaceae at a montane rainforest of ThailandA research plot of 15 hapiot was established and the tree census in 7.5 ha area and identification in 3.0 ha area were completed. Gaps in 3.0 ha area was also mapped. Preliminary data analysis clarified that many Fagaceae species showed the distribution pattern associated with special topography or gaps. The niche differentiation among Fagaceae species will be analyzed qualitatively near future.