352 Part IV. Chapter 1. 
on the latitude or height above sea-level, distance from sea-coast and the 
character of the soil. The forest is continuous in the southern part of Labrador, 
the only exceptions being the summits of rocky hills and the outer islands of 
the Atlantic coast. North of latitude 53°, the higher hills are treeless and the 
size and number of the barren areas (Barren Formation) increase rapidly, 
until in latitude 55°, the trees are confined to the margins of small lakes and 
in the valleys of the rivers. Leaf River, which empties into Ungava Bay, is 
the northern limit of forest trees on the west side of the Bay, and a line from 
that river to the mouth of Nastapoka River would represent a close approxi- 
mation to the northern limit of trees in western Labrador. The barren grounds 
on the east coast at Davis Inlet (56°) are confined to the headlands and islands 
which remain treeless to the south of Hamilton Inlet, while about the heads 
of the larger bays and on the lowlands of the small river valleys, the country 
is well timbered. Pinus Banksiana prefers the dry sandy drift ridges and rocky 
hills, where it is often found along with the black spruce Picca nigra. lt 
occurs abundantly inland and reaches its northern limit on the south branch 
of the great Whale River. Longitude 71° W. seems to mark its eastern limit. 
The distribution of Picea alba depends on the soil, occupying the areas of 
re-arranged drift of the river-valleys and marine deposits along the coast, of 
to the heavier drift of the interior, but as an element of the forest except in 
the Hamilton River valley, it is never important. 
Picea nigra on the other hand is the most abundant tree of Labrador and 
constitutes over ninety per cent of the forest (Picea nigra-Facies). It grows 
freely on the sandy soil which covers the great Archacan areas, and thrives 
as well on the dry hills, as in the wet swampy ground between the ridges. 
The growth is thick everywhere on the southern watershed, while at its northern 
limit, which is the limit of tree growth, it develops large branches and with 
the larch is the last tree encountered before entering the barren grounds or 
tundra. Adies balsamea is found nearly to the edge of the tundra and throughout 
the forest it grows more or less plentifully about the margins of the larger 
lakes and banks of the rivers (Abies balsamea-Facies), preferring moist 
alluvial soil, while the larch Zarix americana everywhere in Labrador is found 
growing in the cold swamps (Larix americana-Facies). It continues as 
a tree to the northern margin of the forest, where Picea nigra becomes a shrub. 
The range of Populus tremuloides depends to a great extent on the nature 
of the soil and in the western half of the peninsula the tree is most abundant 
where it grows on the unmodified glacial till of the drift ridges. Cape Jones 
on the Hudson Bay coast is the northern limit of the aspen, while inland it. 
is found at latitude 54°. The balsam poplar, P, dalsamifera, extends farther 
south than the aspen and it confines itself to the heavy clay soil of the river 
valleys, or to the modified drift of the Cambrian areas. Betula papyrıfera ®# 
found everywhere throughout the southern portion of the peninsula, while 7 Aa 
oceidentalis hardly enters the peninsula about the foot of James Bay an 
Mistassini Lake. 
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