WESTERN YELLOW PINE IN OREGON. 7 
found in a squirrel cache. Undoubtedly a considerable proportion 
of the seed crop is eaten by animals, since the seed is large and 
attractive. In Oregon, yellow-pine seed is larger than it is farther 
east. The number of seeds to the pound from eastern Oregon trees 
is between 8,000 and 9,000. A bushel of unopened cones will usually 
yield about 1J pounds of seed. 
GERMINATION. 
The seed germinates fairly freely, but in Oregon not until the 
spring following its dissemination. Laboratory tests of clean seed 
show that from 60 to 85 per cent of it is fertile, and that most of it 
germinates between four and eight weeks after sowing. 
Field studies indicate that young seedlings are most abundant in 
the exposed spots in the forest, such as on scabby ridges, where the 
mineral soil is naked. Here germination may be the best, but the 
mortality of the seedlings the first year is the largest. 
In certain parts of Oregon, particularly on the very dry pumice 
soils of the upper Deschutes Basin, it is noticeable that a very large 
proportion of the seedlings come up in clumps, from 2 to over 50 being 
crowded into a space as large as a half dollar. It has been suggested 
that these clumps originated where a cone accidentally became buried. 
But such is not the case in this particular locality. They have come 
from bunches of seed which were buried by provident chipmunks. 
(See PL II.) Some counts made in Crook County of the reproduction 
in the forest showed that 85 per cent of all the 1-year-old seedlings 
were in these chipmunk-sown groups. Much more seed must be 
sown broadcast by the wind on the surface than is accidentally left 
in these chipmunk caches, yet it is evident that the seed which is 
buried has a very much better chance of germination than that 
which lies on the surface. This is particularly so on the drier and 
looser soils, where the chipmunks may actually be considered an 
aid to reproduction. The competition in growth between the seed- 
lings in these clumps becomes very keen early in their lives and they 
thin out rapidly, though it is not unusual to find ten or a dozen seed- 
lings four feet high growing from a single hole. One unusual in- 
stance was noted where 29 fourteen-year-old saplings were living in 
a cluster. One-year-old seedlings in these chipmunk-sown clumps 
have been found to be less likely to succumb to drought than solitary 
seedlings, perhaps because they give each other protection. 
It is not infrequent to find a dense row of seedlings, a veritable 
natural hedge from 25 to 75 feet long, located in the path of mineral 
soil and ashes left after a fallen tree had burned up. The cause of 
these hedges is not perfectly understood. 
