WESTERN YELLOW PINE IN OREGON. 



23 



Table 8. — QvMity of sound yellow-pine logs^ in the Blue Mountain region of Oregon. 



Lumber grades. 



Test A 



, good quality timber, 

 log grades. 



Test B 



, poor quality timber, 

 log grades. 





1 



2 



3 



All. 



1 



2 



3 



AU. 



B and better 



Per 

 cent. 

 18.8 

 17.4 



8.0 

 13.6 

 14.3 



7.2 

 .8 



4.7 

 10.9 



4.3 



Per 



cent. 



3.0 



5.9 



3.8 



15.9 



28.5 



9.8 



2.8 



13.8 



13.8 



2.7 



Per 



cent. 



0.2 



1.2 



2.5 



4.2 



14.8 



12.6 



4.5 



22.9 



31.0 



6.1 



Per 

 cent. 

 8.1 

 8.9 

 5.0 

 11.8 

 19.3 

 9.6 

 2.5 

 12.9 

 17.6 

 4.3 



Per 

 cent. 

 17.4 

 15.8 

 8.4 

 10.8 

 14.6 

 4.9 

 2.2 

 8.6 

 14.4 

 2.9 



Per 



cent. 



4.3 



6.4 



5.5 



12.1 



21.4 



5.9 



6.9 



13.0 



20.1 



4.4 



Per 



cent. 



1.5 



2.9 



4.3 



2.6 



10.3 



5.3 



18.6 



25.0 



23.9 



5.6 



Per 



cent. 

 3.7 



C select 



5.3 





5.1 





7.2 



No. 2 shop 



No. 3 shop 



15.3 

 5.6 





12.6 



No. 2 common 



18.7 





21.7 



No. 4 common . . . 



4.9 







Total 



100.0 

 39 



100.0 

 35 



100.0 

 26 



100.0 

 100 



100.0 



8 



100.0 

 44 



100.0 

 48 



100.0 



Per cent of each log grade 



100 







1 Green lumber. Depreciation in drying not provided for. 

 GROWTH.1 



INDIVIDUAL TREES. 



Because of the wide range of conditions under which it grows the 

 rat€ of growth of yellow pine is exceedingly variable, perhaps rather 

 more so than that of most species. In very favorable situations it 

 grows so much each year that it would be classed as a rapid-growing 

 species; in unfavorable situations it is exceedingly slow. In eastern 

 and central Oregon its average rate of growth is somewhat more than 

 in the southern Rocky Mountain region and the southwest, and 

 decidedly more than in the Black HiUs of Dakota.^ The upper slopes 

 of the Sierras in California is the region of most rapid growth. The 

 growth there is probably about the same as on the Siskiyou Moun- 

 tains and the west slope of the Cascade Mountains, the region of most 

 rapid growth in Oregon. For the Siskiyou and Cascade regions, 

 however, no specific growth data are available. 



Broadly speaking, during its first 10 or 15 years yellow pine grows 

 very slowly; then follows a period of 75 or 100 years in which both 

 diameter and height growth are rapid, exceptionally thrifty trees 

 making an increase of one-half inch in diameter and 2 feet in height 

 in one year. By its one hundred and fiftieth year the height incre- 

 ment has fallen off very much, the tree has nearly reached its mature 

 height, and thereafter grows but a foot or two each decade. Diam- 

 i-Xo.T growth also decreases after the first century of life, the rings 

 become narrower and narrower with age, and on very old trees, or 

 those that have been suppressed, they are so fine as to be hardly 

 distinguishable except with a magnifying glass. It is usual, there- 

 fore, for the annual rings to be broad and well defined in young trees 



> The table.s and some of the other material in this chapter are taken from the manuscript report prepared 

 by Mr. O. A. Bright, forest assLstant, entitled "A Study of the Growth of Yellow Pine in Oregon," which 

 embo'liei in detail the results of the field study of this species made by the Forest Service in 1910-11. 



' Forest Service Circular 127, " Forest Tables— Western Yellow Pine." 



