Structure and dynamics of riparian forests in the warm-temperate region

1.屋久岛低地河岸林的河岸组成通过与坡地森林植物群的比较，根据河流的特征，对河岸林的组成进行了分类：（1）地表过程类型（冲刷与沉积）;（2）集水区的空间尺度。低地河岸林干扰频率高的主要成分是冷温性森林中常见的落叶乔木。2.冲刷区河岸林的结构与动态研究了暖温带一级河谷的河岸林结构变化和干扰状况。地形通过1）光照和土壤水分状况的变化严重影响次生林的物种组成、树木大小分布和演替，3.沉积区河岸林的结构与动态对九州南部暖温带冲积扇上的天然林结构进行了调查，并与坡面上的森林结构进行了比较。坡地林分被总状假鹰爪占据。另一方面，在冲积扇中，Quercus gilva占主导地位，与大岩石沉积物上的Acer palmatum和Cornus controversa以及基质沉积物上的Ulmus Davidiana和Sapindus Mukoross相关。不同类型的干扰影响了林分结构的变化，提供了不同类型的更新生境。

1.Riparian component of the lowland riparian forests in Yakushima IslandThrough comparisons with the flora of slope forests, components of riparian forests were categorized according to the features of river : 1)type of earth surface process (scouring vs. sedimentation), 2)spatial scale of catchment area. Main components of lowland riparian forests with high frequency of disturbance were deciduous trees which are common in cool-temperate forests2.Structure and dynamics of riparian forest in scouring areaStructure variations and disturbance regimes were investigated in an 1-order valley in the warmtemperate region. Topography severely affected to the species composition, tree size distribution and succession of secondary forests through the variaion in 1)light and soil moisture regimes, and in 2)the type and frequency of distrurbance.3.Structure and dynamics of riparian forest in sedimentation areaStructure of a natural forest on an alluvial fan in the warm-temperate region in southern Kyushu was investigated and compared with the forest structure on a slope. The slope stand was occupied by Distylium racemosum. On the other hand, Quercus gilva dominated in the alluvial fan associated by Acer palmatum and Cornus controversa on sediments of large rocks and by Ulmus Davidiana and Sapindus Mukoross on sediments of matrix. These variation of forest structure was affected by various types of disturbance providing different kind of regeneration habitats.