Abstract
The purpose of this study is to clarify regeneration patterns of the beech (Fagus crenatd) forest on flat and sloping sites in N.E. Nagano Prefecture. Two 80m x 80m quadrates were established : on flat surface (FS) and on slope surface (SS), respectively. In each quadrate, forest structure, the number of seedlings, saplings and fallen trees, and the diameter of fallen trees (at 1.3 m from their roots) were surveyed. The mean plant coverages of subcanopy and herb layer at SS were higher than those at FS. In contrast, the mean plant coverages of second shrub layer and dwarf bamboo were higher at FS. Total basal area of all tree species was higher at FS, but there were more trees at SS. Coexistence analysis of beech showed that middle and small DBH beech coexisted at FS, but large DBH beech rarely coexisted with middle and small beech at FS. At SS, there was no similar relation of coexistence. Regarding the structure of both forests, the patchy structure of FS was clearer than that of SS. Moreover, the number of fallen trees was greater at SS, but their size was smaller there. Tree fall may occur more frequently at SS. Successors of beech rarely grow at FS because of a thick dwarf bamboo layer. This fact indicates that the regeneration at FS is discontinuous. On the other hand, the regeneration at SS seems to occur continuously, because successors of beech grow well under a less thick dwarf bamboo layer. The regeneration patterns of two types of beech forest were clearly different on FS and SS sites.
