24 



BULLETIN 604, U. ' S. DEPARTMENT OF AGRICULTURE. 



continues for about 200 years, after which it drops off, slowly at 

 first, but more and more rapidly as old age approaches. The period 

 of maximum diameter growth follows closely the period of max- 

 imum height growth, beginning about the time height growth cul- 

 minates. The maximum rate is attained shortly after the periodic 

 annual height growth falls below the mean. 



Table 14 gives, for the sake of comparison, the average diameters 

 breasthigh at different ages for trees growing in different localities. 

 Considerable difference will be noted in the growth rate prevailing 

 in the localities represented, but it also will be found that the 

 period of rapid growth corresponds closely in every case. 



Table 14. — Diameter growth of incense cedar outside hark at breastheight. 



[CUKVED.] 



Locality. 



Eldo- 

 rado 



Na- 

 tional 

 Forest. 



Plumas 



Na- 

 tional 

 Forest 

 (T. 24 

 N.,R. 

 5E.). 



Shasta 

 Na- 

 tional 

 Forest. 



Modoc 

 Na- 

 tional 

 Forest. 



Kern 



Na- 

 tional 

 Forest. 



Tahoe 

 Na- 

 tional 

 Forest. 



Plumas 



Na- 

 tional 

 Forest 

 (T. 24 

 N.,R. 

 10 E.). 



Kla- 

 math 



Na- 

 tional 

 Forest. 



Diameter breasthigh outside bark. 



Aver- 



100. 

 120. 

 140. 

 160. 

 180. 

 200. 

 220. 

 240. 

 260. 

 280. 

 300. 

 320. 

 340. 

 360. 

 380. 

 400. 



Years. 



Inches. 

 1.6 

 3.8 

 8.7 

 13.9 

 19.2 

 23.6 

 27.0 

 29.7 

 31.8 

 33.5 

 35.2 

 37.0 

 38.7 

 40.4 



Basis number of stump 

 analysis 



27 



Inches. 



Inches. 



Inches. 



Inches. 



Inches. 



Inches. 



0.1 



1.4 



0.4 



1.6 



1.1 



1.2 



2.1 



3.4 



1.8 



3.8 



2.5 



3.8 



5.4 



7.2 



5.2 



6.3 



5.3 



5.7 



8.7 



11.4 



9.0 



12.9 



8.1 



8.9 



12.6 



16.0 



12.8 



17.2 



11.1 



12.2 



17.4 



20.0 



16.6 



20.9 



14.1 



15.5 



23.2 



23.4 



20.1 



24.0 



17.0 



18.4 



25.4 



26.2 



23.0 



26.7 



19.7 



20.8 



27.8 



28.4 



25.5 



28.9 



22.0 



22.5 



30.2 



30.6 



28.0 



30.8 



24.0 



24.0 



32.5 



32.6 



30.3 



32.4 



25.8 



25.3 



34.6 



34.6 



32.6 



33.8 



27.5 



26.6 



36.6 



36.6 



34.8 



35.0 



29.1 



27.9 



38.5 



38.4 



37.0 



35.9 



30.5 



29.9 



40.1 



40.0 





36.9 



31.9 



30.2 



41.7 



41.4 





37.7 



33.1 



31.1 



43.1 



42.5 





38.6 



34.3 



31.9 



44.4 

 45.3 



46.0 







39.4 



35.3 



32.5 

 33.1 



33.7 























100 



37 



26 



23 



20 



101 



Inches. 

 1.0 

 2.3 

 5.0 

 8.0 

 10.7 

 13.5 

 16.2 

 18.9 

 20.3 

 23.0 

 24.4 

 25.7 

 27.0 

 28.3 

 29.6 

 31.0 

 32.3 

 33.5 



Inches. 

 1.3 

 3.2 

 6.4 

 9.8 

 13.6 

 17.8 

 21.3 

 23.6 

 25.7 

 27.8 

 29.8 

 31.7 

 33.6 

 35.4 

 36.9 

 38.2 

 39.2 

 40.1 

 40.9 

 41.6 



360 



VOLUME GROWTH. 



The cubic contents of the entire stem and the board-foot contents 

 of the merchantable portion of trees of different ages grown in 

 virgin stands are given in Table 15, together with the average 

 heights and diameters on which these volumes are based. 1 



1 Complete volume tables will be found in the Appendix. 



