13 巻 (1996) 1 号 p. 51-57
A phytosociological survey was carried out in beech (Fagus crenata) and birch (Betula ermanii and B. platyphylla var. japonica) forests on the western side of Mt. Norikura in central Japan with the aim of deriving basic information on the effects of grazing on vegetation. Some observations on basic differences such as changes of architecture and floristic composition of forests were made in communities subjected to grazing and are herein presented along with general information regarding the vegetation of the area. Three types of plant communities were distinguished based on species composition in the area. The major type found in the grazed area was further divided into two communities : one was characterized by a dense shrub layer hindering the growth of the herb layer, and the other showed less dominance of the shrub layer and a luxuriant growth of the herb layer. This reduction of the shrub layer was induced as an initial result of cattle grazing ; nevertheless, the community was basically uniform in species composition. Invasion of new species resulting in a change in floral composition of the forest was found only at the sites with canopy disturbance.