Abstract
A control diagram of crown and stem form was attempted to construct based on the analysis of relationships among several stand characteristics. The data was collected from 32 young even-aged stands of Cryptomeria japonica. When stem length from top to a definite diameter (x) and that from top to DBH (D) were abbreviated as Lx and LB respectively, the correlation between Lx/x and LB/D became stronger with increase in x, although the data scattering was wide. Lower correlation at smaller x indicated that the stem shape above a certain diameter was similar despite difference in the LB/D ratio. A linear regression was established between both ratios for each x. Furthermore, the relationship between the reciprocal of mean tree height/mean DBH ratio and the relative-spacing index (SR) could be also approximated by a linear regression, resulting in a mathematical expression of mean DBH by both stand density and mean tree height. From these regressions, Lx could be expressed as a function of stand density and mean tree height. By combining a clear length model to these relationships, a diagram showing relationships among stand density, clear length, crown length ratio, and definite diameter height could be obtained for each tree height class.
