WESTERN YELLOW PINE IN OREGON. 
23 
Table 8. — Quality of sound yellow-pine logs 1 in the Blue Mountain region of Oregon. 
Lumber grades. 
B and better.. 
C select 
D select 
No. 1 shop 
No. 2 shop 
No. 3 shop 
No. 1 common. 
No. 2 common . 
No. 3 common. 
No. 4 common. 
Total 
Per cent of each log grade . 
Test A, good quality timber, 
log grades. 
Per 
cent. 
18.8 
17.4 
8.0 
13.6 
14.3 
7.2 
.8 
4.7 
10.9 
4.3 
100.0 
39 
Per 
cent. 
3.0 
5.9 
3.8 
15.9 
2.8 
13.8 
13.8 
2.7 
100.0 
35 
Per 
cent. 
0.2 
1.2 
2.5 
4.2 
14.8 
12.6 
4.5 
22.9 
31.0 
6.1 
100.0 
All. 
Per 
cent. 
8.1 
8.9 
5.0 
11.8 
19.3 
9.6 
2.5 
12.9 
17.6 
4.3 
100. 
100 
Test B, poor quality timber, 
log grades. 
Per 
cent. 
11 A 
15.8 
8.4 
10.8 
14.6 
4.9 
2.2 
8.6 
14.4 
2.9 
100.0 
Per 
cent. 
4.3 
6.4 
5.5 
12.1 
21.4 
5.9 
6.9 
13.0 
20.1 
4.4 
100.0 
44 
Per 
cent. 
1.5 
2.9 
4.3 
2.6 
10.3 
5.3 
18.6 
25.0 
23.9 
5.6 
100.0 
48 
All. 
Per 
cent. 
3.7 
5.3 
5.1 
7.2 
15.3 
5.6 
12.5 
18.7 
21.7 
4.9 
100.0 
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 
rate 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 Kocky Mountain region and the southwest, and 
decidedly more than in the Black Hills of Dakota. 2 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- 
eter 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 
i The tables and some of the other material in this chapter are taken from the manuscript report prepared 
by Mr. G. A. Bright, forest assistant, entitled "A Study of the Growth of Yellow Pine in Oregon," which 
embodies in detail the results of the field study of this species made by the Forest Service in 1910-11. 
2 Forest Service Circular 127, "Forest Tables— Western Yellow Pine." 
