10

is composed mainly of fresh, unweathered particles of silt or fine sand, in
part supplied by the present glaciers, which have become mixed with
enough organic matter to form a fertile silt loam or sandy loam.

The beginnings of development of an equilibrium profile can be seen
on low, drift-covered ridges, some large river terraces of glacio-fluvial
origin, and on the deposits of several presumably ice-dammed lakes. In
these places, under the influence of the prevailing coniferous forest cover,
grey, lime-poor, iron- and aluminium-rich, podsol soils are being developed,
and the entire region is included in the area of grey wooded soils of the
podsol zone that covers most of the northern parts of the western Canadian
provinces (Kelley and Farstad, 1946).

FLORA

Timber-line is at about 5,500 feet. The forest cover below this level
is predominantly coniferous, with the proportion of deciduous trees increas-
ing markedly toward the eastern, drier regions. The main forest trees are:

Average
diameter (at Maximum
breast height) | diameter at
in mature breast height,
stands, inches
inches
ee ee ee
Lodgepole pine (Pinus contorta var. murrayana)......... Di 20
Balsam fir (Abies lasiocarpa).......................... 8 50
White spruce (Picea canadensis)................... XE 15 40
Black spruce (Picea mariana)......................... small—confined to muskegs
Engelmann’s spruce (Picea engelmannt)................ 10 30
Aspen poplar (Populus tremuloides).................... 5 15
Balsam poplar (Populus balsamifera).................. 20 60

Less abundant forest trees include paper birch (Betula papyracea),
alder (Alnus incana), and several varieties of willow. The underbrush in the
forests is comparatively light, and consists mainly of soopolallie, buffalo-
berry (Shepherdia canadensis), dwarf birch (Betula glandulosa), mountain
rhododendron (Rhododendron albiflorum), bearberry ( Arctostaphylos
Uva-ursi), and Labrador tea (Ledum groenlandicum). Except in burned-
over areas or ina few over-mature balsam forests, travel on foot is pleasant
and easy. The amount of muskeg, dominated by black spruce and Lab-
rador tea, is not large. At timber-line, stunted balsam fir, dwarf birch, slide
alder (Alnus sinuata), juniper (Juniperus communis var. montana), and
willow cover fairly extensive areas with a thick matted tangle through
which progress is extremely laborious. These areas are interspersed with sub-
alpine meadows and parklands supporting a profusion of flowering plants.
Grassy alps, and slopes covered with false heather (Phyllodoce glanduli-
florus and P. empetriformis) and heath ( Cassiope mertensiana) extend up
to elevations of about 7,200 feet.

Edible wild fruits include at least three species of blueberry, of which
the most common, locally called the northern huckleberry, appears to be a