16 



Table 13 gives tlie variation in diameter growth, for different types 

 of forest in Flathead and Missoula counties, Mont. As would be 

 inferred from the growth of seedlings (Table 11, p. 14) and relation 

 of height to diameter (Table 8, p. 12), the mixed slope type shows the 

 poorest diameter growth. The mixed flat with its denser stand has a 

 retarded diameter growth, but produces the tallest trees (Table S). 

 The pure stands on flat and slope have the best diameter growth, and 

 the slope type leads in height up to 18 inches (Table 8), but the 

 flat type leads in diameter growth. 



Table 13.— Diameter growth in various types. Flathead and Missoula counties. Mont. 



Ago. 



M 



.xed slope. 



Mixed fiat. 



P 



are slope. 



Pure fiat. 



Diam- 





Diam- 





Diam- 





Diani- 







eter | 

 breast > 



Basis. b * 



Basis. 



eter 

 breast- 



Basis eter 1 



breast-, 



Basis. 





high. 1 





high. 





high. 





high. 





Years. 



In. 





In. 





m. : 





In. 





20 







■ 0.7 

 •2.1 





' 0.9 



2.0 





0.9 \ 

 2.3 





30.... 



""'6."s~ 



40. . . . 



1.7 





3 2 





3.4 





3.9 





50.... 



2 7 





4.3 





5.0 





5. 5 





60.... 



3.9 





5.4 





6.4 





7.0 





70.... 



5.0 





6.3 





7.8 





S. 5 





SO. . . . 



90.... 

 100.... 

 110.... 

 120. . . . 

 130. . . . 

 140. . . . 



6.1 

 7 9 



Decade meas- 



7.4 



8.5 1 



9.6 . 

 10.6 « 

 11.8 

 12.8 

 13.9 



Decade meas- 



9.0 

 10.3 

 11.4 

 12. 4 

 13.4 

 14.1 

 14 S 



Decade meas- 



10.0 

 11.4 

 12.5 

 13.3 

 14.1 

 14.9 

 15. 5 , 



Decade meas- 



9.2 ; 



10.0 

 10.7 



11.5 



urements on 



urements on 



urements on 



urements on 



, 47 3-foot 

 stumps 

 107-475 

 years old. 



51 3-foot 

 stumps 

 143-470 



years old. 



, 121 3-foot 

 stumps 

 81-400 

 years old. I 



, 92 3-foot 

 stumps 

 103-269 

 years old. 



150.... 



12.1 





14.7 





15. 5 





1G 1 





160.... 



12.8 





15.6 : 





16.0 





16.6 





170. . . . 



13.4 





16.3 





16.5 





17.1 





180.... 



14.1 





17.1 





16.9 , 





17.5 





190.... 



14.6 





17.7 





17.1 





17.9 





200.... 



15.2 





I 18.3 





lH ..| 



! 



1-18t2 





VOLUME. 



VARIATIOX ACCOEDIXG TO EEGIOX 



With the great variation in form of western yellow pine as shown 

 by the relation of height to diameter (Table 7, p 11) , in diameter 

 growth (Table 12. p. 15), and in density of stand, as shown in the 

 stand tables (pp. 5 to 10), it is not surprising that there is a large 

 variation in volume. In considering volume this variation requires 

 that three general regions be distinguished: the Black Hills; Arizona, 

 Colorado, and open stands in the Rocky Mountain region and south- 

 ern California where there is a deficiency of moisture; and the west 

 slope of the Sierras in central and northern California and in Oregon, 

 and possibly the best stands in eastern Washington and western 

 Montana. 



[Cir. 127] 



