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 (α diversity) and in each forest type (γ diversity) and species turnover among plots in each forest type (β 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.

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Summary 1We studied the effects of seed dispersal mode and seed mass on the migration patterns of woody and herbaceous forest species in an artificial pine forest band growing on a former sand dune. Seven sites in the artificial forest, at least 44 years old, were selected at different distances from an adjacent natural forest (0.1-17.4 km). 2 Both the species richness and the abundance of forest species decreased with increasing distance from the natural forest, indicating that the migration of forest species is limited by seed dispersal. Plants using different seed dispersal modes showed differences in migration rate. 3 Ingested and adhesive species migrated into the artificial forest with the most success. In contrast, almost all the species utilizing other dispersal mechanisms (wind, hoarding or no dispersal mechanism) migrated only into sites near to the natural forest. This is likely to be due to low dispersal capacities. Ant-dispersed species were not found at all in the artificial forest. 4 Migration distances were calculated for 43 species with a frequency of ≥ 5% in at least one site in the artificial forest. Distances were based on the occurrence of the individual of each species furthest from the natural forest, and on the maximum abundance of that species in the artificial forest. The migration distances of the species did not correlate with their seed mass. 5 The dispersal efficiency is an important factor in migration of forest species on a landscape scale, and the migration ability is affected by dispersal mode rather than seed mass.

Abstract. The effects of soil surface disturbance and light level on seedling emergence were examined by creating experimental conditions differing in soil surface treatment and light level in a temperate deciduous broadleaved secondary forest in central Japan. The results of MANOVA showed that soil surface disturbance exerted a favourable influence upon the seedling emergence of many species. Effect of soil disturbance on total density and number of emerged species was greater than that of a high light level. The interaction between soil surface disturbance and light level revealed significant positive effects for seedling emergence, especially for small‐seeded species. The relationship between the percentage of emerged seedlings and seed weight was significantly negative in the soil‐surface disturbed and high light level condition, suggesting that minute‐seeded species largely depend on both factors for seedling emergence. Both soil surface disturbance and high light level had a positive effect on the number of emerged species, suggesting that these factors contributed to species richness at the stage of seedling emergence.

We investigated the seasonal correspondence between the fruiting phenology of fleshy-fruited plants and the abundance of frugivorous birds, in a temperate forest, in central Japan. The majority of fleshy fruits ripened in the fall when frugivorous birds were most abundant. This correspondence occurred earlier than in a warm temperate forest, located in southern Japan; these relationships in East Asia coincide with those of the temperate regions of North America and Europe. We also examined whether the abundance of frugivorous birds led to profitable effects for seed dispersal among fleshy-fruited plants. The Brown-eared Bulbul Hypsipetes amaurotis was considered to be an important seed disperser for many fleshy-fruited plants because of its high frequency of occurrence throughout the fruiting season, and its large gape size, which allowed it to swallow all sizes of fruits found at the study site. Although numerous Brown-eared Bulbuls and other frugivorous birds were present in the fall, fruit removal rates in fall-fruiting species were not always higher than in summerfruiting species. The abundance of frugivorous birds alone could therefore not adequately explain the concentrated fruiting phenology among fleshy-fruited plants.