2024 Volume 106 Issue 10 Pages 279-284
Fraxinus mandshurica is a representative broad-leaved tree species for planted forest in Hokkaido. This study focused on a stand that was planted in 1924 and then largely abandoned until 56 years of age. We described the changes over 40 years (from 56 to 96 years of age) and clarified the factors that influenced the dbh growth of individuals. At the age of 96 years, the volume of F. mandshurica was 190 m3/ha with the average dbh 36.9 cm, indicating that the stand had reached a mature state for harvesting. Significant positive effects of basal area (individual size) and crown length ratio were consistently shown on the dbh growth during the 40 years. No competitive effect from neighboring tree individuals was observed in this period. To reach the mature state earlier, it was thought that early thinning was necessary to ensure crown length ratio of about two-thirds of the tree height. On the other hand, when aiming for a long rotation management, there was a concern that frost injuries would occur frequently in the stem, especially in large-diameter trees.
