Abstract
Cutting of small areas (0.06-0.09 ha) was conducted at a suburban secondary forest in Kyoto city in order to change dominant species from Chamaecyparis obtusa to Pinus densiflora and/or deciduous broad-leaved trees. No species disappeared and more than or equal to 10 species increased at all three plots (upper, middle and lower) by the end of the third year after the cutting. The Fagetea crenatae species, which are main components of deciduous broad-leaved forest, increasedbysix at theupperand middleplots andbyfourat the lower plot. It is considered that the cutting of small areas was effective in increasing the number of deciduous broad-leaved tree species. As most advance seedlings died after the cutting, it was deemed that they made little contribution to change of species composition. C. obtusa, dispersed by wind, occupied high percentage in seed dispersal and seemed to have great influence on regeneration after the cutting. The fact that only two species newly appeared in the third year indicated that dispersal of new species from surrounding forests were limited because the present study site was located within the forest of C. obtusa which has generally low species diversity of woody plants. As for the upper plot (0.09 ha) , the intensive solar radiation, which was over 60% of relative solar radiation, reduced seed germination and seedling survival of C. obtusa, and the vegetation was shifting to the mixed forest of P. densiflora and C. obtusa. As for the middle and lower plots, the percentages of seedlings of C. obtusa were more than 50% in the third year after the cutting, suggesting that selective cutting will be needed for maintaining species diversity of woody plants
