NOTES ON THE ANALYTICAL INTERPRETATION OF GROWTH CURVES 



FOR SINGLE TREE AND STANDS AND ON APPLICATION 



FOR THE CONSTRUCTION OF YIELD TABLE 



FOR SUGI (Cryptomeria Japonica) 



By WATARU TERAZAKI, Forest Expert 



Introductory Remarks 



The following is a supplementary notes on three memoirs published 

 in Bulletin No. 4 of the Forest Experiment Station in 1907 and No. 

 11 in 1915. In 1907 I gave in Bulletin No. 4 of the Forest Experiment 

 Station an account of certain applications of analytical methods to data 

 collected from pure, normally stocked, even-aged stands of Karamatsu 

 (Larix leptorepis) planted near Mt. Asama in Nagano Prefecture, and of 

 Sugi (Cryptomeria) in the Yoshino district in Nara Prefecture. The object 

 of that report w^as to throw Mght upon investigations on equations of 

 curves, showing the mean trends of factors which represent the growth of 

 stand; and also to show the applications of the method of smoothing 

 curves for the construction of yield table from data collected simultaneously. 

 In the paper cited, the data are too few and the results obtained from 

 such an investigations could not be generalized without inquiry as to 

 whether they are applicable to species in general. 



Since then, I have investigated data given in the works on yield 

 tables, published in Germany, Switzerland and Sweden, and have shown 

 that the analytical interpretations cited in the report issued in 1907, 

 could be generalized as applicable to pure, normally stocked, even-aged 

 stands of any species. Furthermore, I have given a solution in first ap- 

 proximations for the relationships on the growth and yield of stand on 

 each quality, of site in different forms of density. 



Thei-e is not less doubt that a proper statistical and analytical study 

 on the growth of stand for the purpose of constructing a yield table 

 would be of very great value. Such a study is of the first importance 

 when we turn to the accurate discussions on the grouping and grading 

 simultaneously surveyed stands as members of the same chain of growth. 



