124 



Forest Club Annual 



The above data cannot be considered general because the 

 figures were based on the measurement of too few trees oc- 

 curing in a restricted locality. However, they may be taken 

 as average figures for similar sites. The data is rather sur- 

 prising in that it shows that on this site Jeffrey Pine between 

 eighteen and forty inches in diameter breast-high is taller than 

 White Fir of the same diameter. The height growth of the 

 Fir is more rapid than that of the Pine. The crown of the 

 Fir is narrow and cone-shaped while that of the Pine is broad 

 and oval. From this fact, since all subsequent cuttings in 

 this type have the nature of a thinning operation, the infer- 

 ence can be drawn that although the Fir is very tolerant and 

 the Pine is intolerant, an immense amount of Fir will be re- 

 quired before it will crowd out the Pine because of the relative 

 size of the crowns of the two species. This will be modified 

 by the policy of marking already described. 



The following table shows relative heights of the two 

 species for different age classes. This table was read from 

 a curve which related the ages and heights given in the above 

 table. 



TABLE 5. HEIGHT GROWTH. 



