林木の材積生長率と年令との関係

The accuracy of growth percentage in volume is an important problem in forest management plan, and so we must investigate the property of growth percentage in volume.
This report deals with the relation between the growth percentage in volume and age.
The investigation was made by use of three conifers, Sugi(Cryptomeria japonica D. D0N.), Hinoki(Chamaecyparis obtusa ENDL.), and Akamatsu(Pinus densiflora SIEB. et ZUCC.).
The results of the experiments are summarized in Tables 1～3, and illustrated in Fig. 1～5.
On the relation between the growth percentage in volume and age, the plotted points are described straight lines on logarithmic cross-section graph or semi-logarithmic one.
This straight line is expressed by the following formulas.
P_v = K_e^<-nt> (Tree at 40 years of age)
P_v = K_t^<-n> (Stand at 80 years of age)
The method of growth percentage in volume has often been used to indicate the past growth of a stand, also this method will be used to predict future growth of a stand.
On the relation among the site quality, tree species and growth percentage in volulme, a definite tendency was hardly recognized.