Abstract
The tree height and breast height diameter (DBH) were measured in a 17-year-old stand to detect the hereditary characteristics of the growth of Cryptomeria japonica (CJ) and Chamaecyparis obtusa (CO). The tree height was measured from the 3rd to 17th year after planting. The mean annual height increment (MH) from the 3rd to 5th year was less than 0.2 m for both trees. Due to the error at the time of planting, the repeatability of clones (RC) fluctuated with the year (35-46% for CJ and 41-56% for CO). From the 6th to 10th year, the MH was 0.4m for both trees, and the variance of replication increased in CJ, but, the RC tended to be stabilized in both trees (37-41%, 53-58%). From the 11th to 17th year, the MH was 0.9m for CJ and 0.8m for CO. Accordingly, the variance of replication decreased in CJ and the RC increased year by year in both trees, being 53-58% for CJ and 56-68% for CO. The DBH was measured from the 9th to 17th year. The mean annual DBH increment was 1.3cm for both trees. At the 9th to 10th year, there was an effect of individual size especially in CO, and the variance of replication in CJ, the RC was low (26-32%, 32-33%). However, at the 11th to 17th year, the variance of replication decreased in CJ. The RC increased markedly for both trees being 42-61% for CJ and 37-78% for CO. Thus, the time lag until the appearance of the hereditary characteristics, especially tree height was greatly affected by the mean annual increment. In CJ, the tree height and DBH were affected by the variation of replication, while in CO, the DBH in the first few years of the survey was affected by the individual size .
