関東周辺におけるブナ自然林の更新

抄録

Regeneration of beech (Fagus crenata Blume) forests was studied around the Kanto district to clarify the difference in regeneration between that on the Pacific side and that on the Japan Sea side. The patch-mosaic structure and the areas of the early, middle and late regeneration stages at the study sites on the Pacific side were similar to those at the study sites on the Japan Sea side. At every developmental stage, the number of beech individuals was lower at the study sites on the Pacific side than at those on the Japan Sea side. At the study sites on the Pacific side the number of other canopy trees was much higher than that of beech individuals. The ratio of beech juveniles (smaller than 10 cm in DBH) to canopy trees (larger than 30 cm in DBH) was much higher at study sites on the Japan Sea side than in those on the Pacific side. At the study sites on the Pacific side the number of beech juveniles was very small. On the Japan Sea side, the number of beech juveniles was higher than that of canopy trees. From these results it is concluded that at study sites on the Pacific side other tree species would replace F. crenata because they regererate constantly with a large number of juveniles, whereas F. crenata has only a small number of juveniles, although large-stemmed F. crenata trees may remain in the forests.