Journal of Agricultural Research 
Vol. XXX, No. 11 
in the vicinity of Moose Lake in the 
Big Creek drainage of the Blackfeet 
National Forest. In 1910 a forest Are 
swept across a glacial valley below 
Moose Lake in a northeasterly direc¬ 
tion. The site of this burn on both 
northerly and southerly slopes around 
Moose Lake furnished an opportunity 
to study the extent to which spruce 
and associate species come in on burned 
The altitude of the valley is 5,000 to 
6,500 feet but the study was conAned 
within a range of 5,000 to 6,000 feet. 
Up to the 6,000-foot contour the stand 
12 inches and over in diameter breast 
high consists of 63 per cent Engelmann 
spruce and 37 per cent alpine Ar (Abies 
lasiocarpa ), as shown by the reconnais¬ 
sance survey for a representative 
section in this locality. In board foot 
volume, however, the proportion is 80 
per cent for the spruce and 20 per cent 
for the Ar, accounted for by the differ¬ 
ence in size of the two species, which 
yielded, respectively, 7.5 and 16.5 logs 
per thousand board feet. 
On the southerly exposures lodge- 
pole pine (Pinus contorta) formed a 
small percentage of the mixture. 
Altitude affects the mixture of the 
stand noticeably. At about the 6,000- 
foot contour the spruce ceases to form 
any considerable portion of the mixture 
(pi. 1). The alpine Ar, however, con¬ 
tinues on to higher altitudes and the 
whitebark pine (Pinus albicaulis) re¬ 
places the spruce. The stands above 
6,000 feet are purely protection forests 
and are disregarded for the purpose of 
this report. 
The number of surviving seedlings 
may be considered a reasonable indica¬ 
tor of site conditions. This conclusion 
is strengthened by an examination of 
the vegetative cover, of which only the 
dominant species of plants and shrubs 
are given below. The thin vegetative 
cover on the upper southwest slope and 
the presence of the more drought-resis¬ 
tant species indicate the severity of the 
site: 
Southwest exposure; vegetation (dominant species 
in order of occurrence): 
Upper slope (13 chains); vegetation very thin— 
20 to 60 jwr cent bare soil; soil shaley— 
Vaccinium membranaceum (?). 
Xerophyllum tenax. 
Salix sp. 
Chamaenerion angustifolium. 
Amelanchier alnifolia. 
Acer sp. scattered clumps. 
Alnus sp. 
Middle slope (13 chains); vegetation thin—10 
to 70 per cent bare soil; moisture at lower end 
of strip— 
Alnus sp. 
Salix sp. 
Chamaenerion angustifolium, 
Xerophyllum tenax. 
Pachystima myrsinites. 
Aquilegia sp. 
Southwest exposure—Continued. 
Middle slope—Continued. 
Acer sp. 
Populus tremuioides. 
Lower slope (13 chains); vegetation cover tlnn 
to dense— 
Kubus parviflorus. 
Menziesia glabella. 
Pachystima myrsinites, 
Xerophyllum tenax. 
Vaccinium sp. 
Acer sp. 
Salix sp. 
Eibes sp. 
Northeast exposure; vegetation (dominant species 
in order of occurrence): 
Upper slope (3 chains); vegetation dense to 
Rubus parviflorus. 
Menziesia glabella. 
Chamaenerion angustifolium. 
Alnus sp. 
Arnica latifolia. 
Moss, covering mineral soil. 
Lower slope (8 chains); vegetation very dense, 
waist-high— 
Menziesia glabella. 
Lycopods and moss (under brush cover). 
Ribes sp. 
Alnus sp. 
Vaccinium sp. 
Arnica latifolia. 
Acer sp. 
As a means of studying the burned 
area a 55-chain transect was run from 
the top of one ridge down a southwest 
slope, across the valley, and up the 
opposite northeast slope to the top of 
the opposite ridge. In addition, ran¬ 
dom sample plots were located at ad¬ 
vantageous points. 
The transect run in this manner en¬ 
abled a very satisfactory study of both 
slopes, and Table I discloses an inter¬ 
esting set of conditions on opposite 
exposures within the same type. The 
varying number of seedlings to the 
acre found on each division of the 
respective slopes is an index of the com¬ 
plex responsible for the restocking. 
More seedlings by a large ratio occur 
on the protected northeastern and 
lower southwestern slopes. The more 
moist condition favoring survival is at 
the same time responsible for a larger 
seed supply. On these sites, too, a 
few mature trees escaped the Are; 
whereas on the upper southwest ex¬ 
posure the drier conditions favored a 
harder burn and the killing of all the 
trees (pi. 2, A and B). 
Despite the absence of mature living 
trees within a chain on each side of the 
transect on the southwest slope, the 
presence of seedlings less than 5 years 
old indicates the continuous reseeding 
of the light-seeded species by wind- ' 
blown seed. Scattered trees, parti¬ 
cularly on ridges, are doubtless the 
sources of these seed. 
Thus the interruption of the natural 
course of plant succession by the forest 
Are has had different effects on the two 
exposures. As presumably the process 
of reseeding gave approximately equal. 
opportunity for reproduction over the 
