WESTERN YELLOW PINE IN OREGON. 9 
were on the south side of these bushes, 11 per cent were sheltered by 
logs or lodgepole pines, and only 6 per cent were in the open, although 
these open spots occupied a considerable proportion of the area. 
In the Blue Mountains the reproduction of yellow pine is very 
abundant, both in the virgin forest and after cuttings. Perhaps it 
is more prolific here than anywhere else. In this region where an 
area has not been burned over by a surface fire for a number of years, 
there is quite commonly a veritable thicket of little trees from a few 
inches to several feet high. Actual counts have shown that there are 
sometimes 14,000 seedlings on a single acre, the ages ranging from 
13 to 21 years. 
The first season most of the growth of the seedling is below ground; 
it forms a top only 2 or 3 inches high with a small tuft of short needles, 
but it grows a taproot from 7 to 12 inches long in its effort to reach 
subsoil moisture. The second year more of a top is formed, but 
growth is slow for at least four years, and does not become rapid in 
any event until the seedling has abundant light. 
Table 3 gives an idea of the rate of growth of the dominant seed- 
lings in average yellow-pine forests in the Blue Mountains, which is 
closely similar to the average growth of seedlings in other forests of 
central and eastern Oregon. In making this table only seedlings 
which had free growing space and looked as though they would live 
at least to the pole stage were included. The growth of even these 
dominant seedlings is exceedingly slow during their first 20 or 30 
years. 
Table 3. — Seedling height growth, Blue Mountains, Oreg. 
[Based on 1,182 measurements.] 
Age. 
Height. 
Age. 
Height. 
Age. 
Height. 
Years. 
Feet. 
Years. 
Feet. 
Years. 
Feet. 
1 
0.2 
5 
0.8 
9 
1.5 
2 
.3 
6 
1.0 
10 
1.7 
x 3 
.5 
7 
1.1 
15 
2.7 
4 
.6 
8 
1.3 
20 
4.0 
EFFECT OF FIRES. 
Western yellow pine is classed commonly as a fire-resistant species, 
probably because in its open stands destructive crown fires are rare; 
but it is by no means immune to damage by fire. Occasionally a fire 
gets into the tops of the trees in a pure yellow-pine forest on a slope 
and sweeps over the whole hillside, perhaps a square mile in extent, 
killing all the trees in its path. This spectacular form of fire damage is 
uncommon, however; by far the greatest amount of damage is done 
by surface fires which work in an inconspicuous way. Light, slowly 
54891°— Bull. 418—17 2 
