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

1.沙捞越热带低地雨林龙脑香科植物的研究在52公顷的样地中，对龙脑香科植物73种和9亚种的分布进行了分析，其中73%的物种具有随地形而异的分布格局。这一事实表明，地形生态位的分化可能有助于在样地中实现龙须草的共存。对非双翅果分类群也进行了同样的分析，得到了相同的结果。通过航空摄影和土地调查估算了林隙形成率和恢复率。有两种类型的林隙：一种是由伴随暴雨的滑坡形成的，另一种是由树木倒塌形成的。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为树种提供了不同的更新生态位。更新生态位多样性对树种共存的贡献将在不久的将来得到分析。对鳞毛蕨属的两个种进行了遗传分析。这两个物种在52ha的当地种群中都表现出高度的遗传分化，表明该物种具有较高的遗传多样性。相反，两个共生物种之间的遗传距离很小，表明两个物种最近发生了生态位分化和物种形成。泰国山地雨林壳斗科植物调查建立了15公顷样地，完成了7.5公顷面积的树木普查和3.0公顷面积的鉴定。还绘制了3.0公顷面积的林隙图。初步数据分析表明，许多壳斗科植物表现出与特殊地形或林隙相关的分布格局。壳斗科植物之间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.