Effects of different forest management systems on plant species diversity in a Fagus crenata forested landscape of central Japan

To clarify how different forest management systems affect the diversity of understory vascular plant species at the plot level and the forest-type level, we examined a forested landscape originally occupied by primary Japanese beech, Fagus crenata Blume, in central Japan. The landscape is currently composed of four types of forest: primary F. crenata forest, shelterwood logged F. crenata forest, abandoned coppice forest, and coniferous plantation. Species richness per plot (alpha diversity) and in each forest type (gamma diversity) and species turnover among plots in each forest type (beta diversity) reached their highest values in plantation forests. While the difference in species composition between primary and shelterwood logged forests was not significant, the other pairs of forest types showed significant differences. Ordination analysis revealed that variation in species composition within the plantations seemed to be related to the dominance of naturally regenerated tree species, which reflected the intensity of tending. Although the species composition of less intensively tended plantations was similar to that of abandoned coppice forests that had been repeatedly cut in the past, their species composition differed from that of the primary forests. This suggests that most of the plantation and coppice forests, which were clear-cut at least once, do not revert to primary forest conditions after management is abandoned.