Differences in plant species diversity in Larix kaempferi plantations of different ages in central Japan

摘要

To clarify the relationships among stand age and species diversity, richness, and composition, we studied the effects of stand age on plant species diversity in Larix kaempferi plantations in central Japan. We also identified which species group, classified by seed-dispersal type and life form, was most affected by stand age. Young plantations (about 15-year-old) had the highest species diversity and richness and included many species not found in older plantations (about 60-year-old). Forty-year-old plantations contained fewer species with animal-dispersed seeds than did younger and older plantations. In older stands, we found both more woody species and more species with animal-dispersed seeds. Although certain species traits (i.e. woody species and species with animal-dispersed seeds) were positively affected, extending the rotation age of plantations did not contribute to meaningfully increased species richness or diversity. These results show some of the contributions of long-rotation plantations to the maintenance of ecological processes and function.