SUGAE PUsTE. 



27 



figures represent rouglily the results under a still greater degree of 

 light or soil suppression. 



It appears from the diameter-growth table that the maximum cur- 

 rent diameter gTowth occurs between 80 and 100 years, which is also 

 the period of maximum height growth. The maximum average 

 annual growth for this 20-year period is 0.37 inch. The rate of growth 

 in diameter decreases less rapidly, however, than the rate of height 

 growth, the current annual exceeding the mean annual growth up 

 to about the hundred and forty-fifth year. Usually the height 

 growth of a tree species culminates before the diameter growth. 

 Whether the sustained rate of height growth apparent m this species 

 is attributable to the fact that the trees measured grew in virgin 

 forest, where then* light requirements were not satisfied during youth, 

 or whether this is an mherent peculiarity, has not yet been fully 

 determined, and can not be until older, more normal second-growth 

 stands are available for study. 



VOLUME GROWTH. 



Table 18, showmg the growth in volume of sugar pine, is derived 

 from tables of average growth in diameter and height at various ages 

 and a volume table for trees of various diameters and heights (see 

 p. 37-38, Appendix). The striking feature shown by this table is the 

 great age to which the tree sustains volume production. Tlie current 

 annual volume growth remains above the mean annual growth for 

 over 400 years, over 300 years after height and diameter growth have 

 culminated. At 100 years of age the annual rate of volume growth is 

 2 cubic feet. It then increases steadily up to an annual rate of 5^ 

 cubic feet at 350 years. The rate of volume growth remains prac- 

 tically constant from that age up to 460 years. No information to 

 indicate its behavior at a greater age has been collected. 



Table 18. — Growth in volume, on the. basis of age, diameter, and hevjht of averaye domi- 

 nant trees, California Sierras. 



Age. 



Average. \'olume. 



Age. 



Average. 



Volume. 



Diameter 

 outsi'le 

 hark- at 

 breast 

 height. 



Total 

 height. 



Cubic 



feet 



outside 



bark. 



Board 



U'.itl 



(StTiliner 



Decimal 



C rule). 



Diamptei- 

 outside 

 bark at 

 breast 

 height. 



Total 

 height. 



Cubic 



feet 



outside 



bark. 



Bonrd 



fe.it 



(Spriliner 



]3ocinin,l 



rule). 



Years. 

 20 

 40 



m 

 10(J 

 12(» 

 lUl 

 160 

 ISO 

 200 



Inches. 

 0.2 

 2. .5 

 7. .5 

 i:i.o 

 IX. 1 

 22.7 

 20. S 

 30. .5 

 33.9 

 37.0 



Feef,. 

 H 

 23 

 45 

 72 

 92 

 lOti 

 lis 

 127 

 135 

 142 







Yedrs. 

 220 

 2)0 

 200 

 2H0 

 3(K) 

 320 

 340 

 300 

 3Hfl 

 4(10 



Ivclici. 

 40.0 

 42.5 

 44.9 

 47.2 

 49. 3 

 61. t 

 53. 5 

 5.5.5 

 57.3 

 59.1 



Feet. 

 MX 

 1.53 



ir.x 



UV2 

 107 

 171 

 171 

 177 

 ISO 

 1S3 



530 



630 



733 



83S 



914 



1,050 



1,1. 5S 



1,270 



1.3S0 



1 , 4SS 



2,a3n 



3,4(10 

 4,120 

 4,8tO 

 5, .570 

 «.(«() 

 7,750 

 7,740 

 8,3H0 

 9. (MO 











31 



71 



120 

 192 



2<;s 



31H 

 135 



110 



210 



4<K) 



WO 



1,290 



1,700 



2 250 



