640 
Journal of Agricultural Research 
Vol. XXX, No. 7 
The application of a covering of litter 
to mask the spots against the raids of 
rodents, and the use of sulphuric acid 
as a fungicide were ineffective. The 
results did not justify the expense of 
these operations. 
In general more deaths were due to 
drought than to any other two causes. 
(Table I.) During dry summers, which 
have been frequent in this region of 
late years, the soil easily dries out com¬ 
pletely to a greater depth than the 
roots of the very young seedlings have 
been able to penetrate. A high evapo¬ 
ration rate occurring at the same time 
soon kills them. Cutworms were next 
in destructiveness. Fungi were not a 
large factor. The remaining classes of 
loss, “accident,” and “missing,” repre¬ 
sent numerous deaths from miscella¬ 
neous causes. Frost heaving is often 
an important cause of loss. 
shrubs filled some of the spots and 
were pressed into a solid mat by snow, 
thus forming a mechanical barrier to 
germination the next spring. 
Yellow pine was early abandoned in 
this work because of the abundance of 
rodents, which seek especially these 
large seeds. On the experimental area 
the western chipmunk ( Tamias quad- 
rivitatus) and a similar animal, Say’s 
spermophile ( Spermophilus lateralis ), 
have been observed to fairly “swarm” 
in August and early September, while 
in late October one is rarely seen. 
Perhaps sowing should be done late, 
even at a sacrifice of some germination, 
in order to avoid them. It is likely 
that one of the principal reasons for 
the success of restocking on certain 
areas by broadcast seeding after the 
1910 fires was the wholesale destruc¬ 
tion of rodents by the fire. 
Table I.— Causes of loss of seedlings in seed spots, Haugan experiment area, Trail 
Gulch 
Species 
Row 
No. 
Date of sow¬ 
ing 
Years 
con¬ 
sidered 
Percentage of loss from various causes 
Fungi 
Cut¬ 
worms 
Drought 
Acci¬ 
dent ° 
Miss¬ 
ing 
Other 
Total 
Picea Engelmanni_ 
1 
Apr. 26,1918 
1918-1920 
7.9 
15.7 
64.1 
1.8 
7.2 
3.3 
100 
Larix occidentalis_ 
2 
Apr. 27,1918 
1918-1920 
17 
9.2 
59 
1. 5 
9.3 
4.0 
100 
Psd. taxifolia_ 
3 
Apr. 29,1918 
1918-1920 
22.2 
14.4 
34.3 
.9 
10 
18.2 
100 
Pinus monticola_ 
4 
Sept. 11,1918 
1919-1921 
2.2 
30.9 
52.9 
.7 
11.8 
1.5 
100 
Psd. taxifolia_ 
5 
Sept. 27,1918 
1919-1921 
0 
9.3 
49.5 
6.2 
35.1 
0 
100 
Larix occidentals- 
6 
Sept. 28,1918 
1919-1921 
3.9 
12.8 
62 
4.2 
14.3 
2.9 
100 
Picea excelsa_ 
7 
Oct. 3,1918 
1919-1920 
2 
22 
71 
1 
4 
0 
100 
Picea Engelmanni_ 
8 
Oct. 2,1918 
1919-1920 
2.9 
14.8 
75.2 
1.6 
4.2 
1.3 
100 
Do_ 
9 
Oct. 4,1918 
1919-1920 
3.5 
20.1 
67.3 
2.1 
5.8 
1.2 
100 
Psd. taxifolia_ 
10 
May 10,1919 
1919-1921 
10.3 
18.3 
55.9 
0 
15.6 
0 
100 
Picea Engelmanni_ 
11 
May 22,1919 
1919-1921 
5.7 
17.1 
56.5 
.4 
20.2 
.1 
100 
Pinus monticola_ 
12 
Sept. 11,1919 
1919-1921 
2.6 
25.7 
44.7 
5.9 
21.1 
0 
100 
Larix occidentalis_ 
13 
Sept. 12,1919 
1920-1921 
11.1 
14.6 
24.6 
22.7 
27 
0 
100 
Psd. taxifolia__ 
14 
Oct. 6,1919 
1920-1921 
3 
30.2 
20.7 
16 
30.2 
0 
100 
Picea Engelmanni_ 
15 
Oct. 7,1919 
1920-1921 
6.4 
32.2 
27.1 
13.6 
20.8 
0 
100 
Larix occidentalis_ 
16 
June 2,1920 
1920-1921 
2.7 
10.8 
8.1 
18.9 
59.4 
. 1 
100 
Picea Engelmanni_ 
17 
June 3,1920 
1920-1921 
1.7 
22.4 
38.7 
12.5 
1 24.6 
.1 
100 
Psd. taxifolia_ 
18 
June 4,1920 
1920-1921 
8.5 
21.3 
17 
34 
19.3 
0 
100 
Picea Engelmanni_ 
19 
May 5,1921 
1921 
5.2 
51.9 
30.8 
1.1 
11.1 
0 
100 
Larix occidentalis- ... 
20 
_do_ 
1921 
4.8 
44.4 
29.1 
.5 
21.1 
. 1 
100 
® Among the miscellaneous causes of loss listed as accident, frost heaving seems to have been the most 
important. 
Stones in seed spots and lying near 
the sowing surface presented mechan¬ 
ical obstacles to seedlings starting on 
the thin layers of soil. When the life 
of a seedling depends upon the deep 
penetration of its root before the dry 
summer season arrives, such obstacles 
are often fatal. Stones lying on the 
surface become very hot in the sun, 
attaining temperatures injurious to 
growing tissue; these possibly caused 
the death of seedlings next to them in 
some instances. In other cases the 
seed spots formed little pockets on 
the slope which caught rolling stones 
and debris. Leaves from hardwood 
The tendency for western white pine 
seed to reserve a large part of its ger¬ 
mination until the second season after 
sowing is well known. Contrary to 
expectations, Engelmann spruce twice 
exhibited such delayed germination. 
Both times the occurrence was in series 
sown in the spring, whereas fall sow¬ 
ings were entirely free from such hold¬ 
over germinations. 
There was a complete loss before 
August of all germinations in screened 
spots sown in 1921. This is apt to 
happen to seed spots in this region 
when a dry year follows sowing. Sur¬ 
vival data show that in most cases, 
