車道による周辺植生への影響(III)

The purpose of the present note is to show how natural forests have been destructed by road construction in natural area. In the first reports the author discussed the methodology to analyse these problems, and the second reports he discussed the impact of road on various developmental stages of the vegetation on the lava flow. In this paper he tries to analyse the influence of roads among wilderness area. As the stand of the study, the special natural monument of Kasugayama virgin forest (Nara Prefecture) is selected. In the forest had been constructed sight-seeing road in 1930. The author investigated the floristic composition and made a vegetation map on a scale of 1 : 3,000. The difference of vegetation on the vegetation map show the difference of human impact which caused by road construction. The influenced zone are clearly drawn on the map (Fig. 3). The width of the belt influenced is 10-20m from the road, but some-times is more than 50m. The author supposes, that the difference of the width may be reduced to the location of the road and to the variance ofgeomorphological aspect along the road.Article信州大学農学部紀要 12(1): 1-18(1975)departmental bulletin pape