Janzen (1970) and Connell (1971) proposed that distance- and/or density- dependent juvenile mortality caused by species-specific natural enemies could generate tree species diversity. Although the hypothesis is supported by many studies in both tropical and temperate forests in the context of negative feedback between conspecific adults and the juveniles (but see Mangan et al. 2010), little is known in species replacements from conspecific to heterospecifics near the adults.

To examine whether the species replacement is occurred, we investigated density, size, age and leaf damage for juveniles of both conspecific (Cornus controversa) and heretosecifics (i.e. Quercus mongolica, three Prunus spp.) at three distances (i.e. beneath, near, far) of adults of Cornus in a deciduous broad-leaved forest. Amount of infected leaves were also investigated with the same manner.

Both the age and height of Cornus juveniles were smaller near the adults than far, whereas both were not different between the distance for the other species. Both the amount of infected leaves fallen from the canopy and leaf damage of juveniles caused by the pathogens and herbivores were higher near than far from the adults.

The results indicate that species replacement from conspecific to heterospecific near the adults is facilitated by species-specific natural enemies.