SITKA spruce: uses, growth, management. 



27 



VOLUME. 



The volume growth of Sitka spruce is also rapid and well sus- 

 tained. Table 8 indicates the average diameter, height, and volume, 

 and the average volume growth that may be expected of dominant 

 Sitka spruce trees in the spruce region of Oregon and Washington. 

 The figures for diameter, height, and board-foot volume were taken 

 from Tables 6, 7, and 11. Those for cubic-foot volume were sup- 

 plied from a tree diagram in which the figures for average diameters 

 and heights were combined with complete stem analyses of 10 domi- 

 nant trees. 



As indicated in this table, the periodic annual volume increment 

 of spruce at 100 years exceeds 5 cubic feet, and at 300 years it is 

 double this amount. The periodic annual growth continues greater 

 than the mean annual for a long time after 300 years. At 100 years 

 of age the volume of the entire stem without bark of dominant Sitka 

 spruce trees approaches the high figure of 300 cubic feet, and at 200 

 and 300 years it exceeds 1,000 and 2,000 cubic feet respectively. 



Table 8. — Average diameter, height, and volume and average volume growth of 

 dominant Sitka spruce trees in Oregon and Washington. 





Size. 



Volume. 



Annual volume growth. 



Age. 



D. o. b. 



at 15 ft. 



Total 

 height. 



Entire 

 stem 



without 

 bark. 



From 

 stump 

 height 

 to top 

 d..i. b. 



rjfio 



inches. 



Periodic. 



Mean. 



Periodic. 



Mean. 



Y~eaTS. 



Inches. 

 2.0 

 9.5 

 15.7 

 20.5 

 24.4 



28.1 

 31.5 

 34.7 



37. 7 

 40.0 



43.4 

 46.2 

 48.8 

 61.4 



54.2 



Feet. 

 31 

 70 

 104 

 132 

 154 



173 

 188 

 200 

 210 

 218 



224 

 228 

 232 

 234 



230 



Ou.ft. 

 3 

 22 



87 

 175 

 279 



400 

 538 

 690 

 859 

 l,O30 



1,219 

 1,417 

 1,617 

 1,818 

 2,020 



Bd.ft. 



Cu./t. 



0.15 



.9 



3.2 



4.4 



5.2 



0.0 

 0.9 

 7.0 

 8.4 

 8.8 



9.2 

 9.9 

 10.0 

 10.0 

 10.1 



Cu.ft. 



0.15 



.5 



1.4 



2.2 



2.8 



3.3 

 3.8 

 4.3 



4.8 

 5.2 



5. 5 

 5.9 

 0.2 

 6. 5 

 6.7 



Bd.ft. 



Bd.ft. 



40... 









60 



200 



070 



1,230 



1,900 



2,700 



3, 690 

 4,040 

 5, 000 



0,720 

 7,800 

 8, 940 



10,010 



11,170 





4 



80 



20 

 28 



30 

 40 

 40 

 47 

 51 



53 

 54 

 57 

 55 

 50 



8 



100 



12 



120 



10 



140 



20 



160 



23 



ISO 



25 



200 



28 



MO 



30 



240 



32 



2'M 



34 







36 



300 



37 







YIELD. 



The yield of Sitka spruce per acre in the virgin forest varies con- 

 siderably with its representation as a species in the stand, with the 

 density of stocking, and with the quality of site. Although available 

 data are not. sufficient to furnish yield fables for the wide r:ni<_ r <'' 



