8 BULLETIN 418, U. S. DEPARTMENT OF AGRICULTURE. 
DEVELOPMENT OF SEEDLINGS. 
Although seedlings start with considerable vigor after each good 
seed year, their mortality during the first year is exceedingly high. 
In the early summer the forest floor is sometimes thickly dotted with 
freshly sprouted seedlings, while on the same area the next year, as a 
consequence of the summer drought and the winter ground heaving, 
there will be but an occasional living seedling. A count of the seed- 
lings on 67 small sample plots distributed over five acres, in the fall 
of 1910 (after the excellent seed crop of 1909 and the very dry season 
of 1910), showed that 79 per cent of the seedlings which started that 
spring had died by fall. 1 Probably not one seed in ten escapes the 
birds and rodents; and, of those that do germinate, probably as many 
are killed by late frosts immediately after germinating or by frost- 
heaving the first winter or by drought the first summer. It is esti- 
mated that in eastern Oregon hardly more than one seedling in a 
hundred lives to be 2 years old. After the first year the mortality 
from drought is very slight. 
The year-old seedlings seem to do best beneath the partial shade 
of the mother trees, probably because of the protection which they 
are afforded against drying sun and winds, and perhaps against 
frost as well. Older seedlings do not do well in dry places directly 
beneath old trees, because of the absorption by the roots of the latter 
of all the available soil moisture; the seedlings that ultimately suc- 
ceed are those in the gaps between the clumps of old trees or beneath 
those which have recently died. For some reason those in the latter 
situation are particularly flourishing in eastern Oregon. On dry 
soils, clumps of brush and mats of squaw-carpet {Ceanothus pros- 
tratus) seem to assist yellow-pine reproduction, probably by their 
effect in conserving the soil moisture. 
For these reasons and for other causes which are not thoroughly 
understood, yellow-pine reproduction is extremely patchy in the 
virgin forest; here there will be almost a thicket of young trees, and 
near by, under seemingly similar conditions, there will be little or no 
reproduction. 
In dry situations bordering the limit of yellow-pine growth, the 
reproduction seems to be greatly benefited by the protection that 
bushes afford, and it is conspicuously more abundant on the sheltered 
north side of clumps of bushes than elsewhere. An examination 2 of 
an area adjoining the desert in Crook County showed the following 
interesting results: Of all the yellow-pine seedlings 70 per cent were 
on the north side of sagebrush and bitterbrush bushes, 13 per cent 
1 Manuscript report, "Western Yellow Pine Reproduction," by George A. Bright, forest assistant. 
2 Manuscript report by Forest Supervisor M. L. Merritt, "Occurrence of Western Yellow Pine Seedlings 
in Openings in the Edge of the Deschutes National Forest, Bordering on the Desert." 
