Effects of extending rotation period on plant species diversity in Larix kaempferi plantations in central Japan

We compared the plant species diversity of forest-floor vegetation in long-rotation Larix kaempferi plantations with standardrotation plantations and abandoned coppice forest in central Japan. Species diversity and richness did not differ between the standard-and longrotation plantations. However, the composition of tall-tree species, of different seed-dispersal types, in long-rotation plantations differed from that in standard-rotation plantations, but was similar to that in abandoned coppice forest. These results indicate that, in particular, long-rotation plantations contained more tall-tree species with animal-dispersed seeds, which in turn suggests that long-rotation plantations may be better for colonization of tall-tree species with this type of seed dispersal. The relatively long period since management in long-rotation plantations may play a significant role in the growth, reproduction, and seedfall of naturally regenerated tall-tree species with animal-dispersed seeds. Therefore, long-rotation plantations may maintain and restore species composition via recovering ecological function.