スギ,ヒノキ単木の成長経過

The author carried out this study with the past growth curves of Sugi (Cryptomeria japonica D. Don) and Hinoki (Chamaecyparis obtusa Endl) trees.
The method of stem analysis is an accurate and good method to determine the past ghowth of individual trees. For each sample tree, the growth in height, d. b. h basal area and volume are measured.
The results are shown in Table 1 - 2. Fig 1 shows the relation between current annual growth and mean annual growth in height, d. b. h and volume. Table 3 shows the growth percentage in height, d. b. h, basal area and volume.
There is a definite relationship between the curves of current annual and mean annual growth. The two curves cross at the crest of the mean annual growth.
The curves of current annual growth in height reached its crest and starts to fall in 15 years, and mean annual growth reached its crest and starts to fall in 20-30 years.
The curves of current annual growth in d. b. h reached its crest in 15-20 years, and mean annual growth reached its crest in 25 years.
The curves of current annual growth in volume reached its crest in 25-30 years, and mean annual growth will be reached its crest in 40-60 years.