Climatic conditions are best reflected by the natural vegetation of a country. Except for the tundra region in Arctic Quebec, the whole of the territory is covered by a large portion of the great Canadian forest: mostly composed of conifers, although the small southern part had a forest of hardwood, before it was partly cleared for settlement.
The treeless tundra formation covers a large area in the Ungava peninsula, north of a line running from Richmond Gulf on the eastern shore of Hudson Bay to near Hopes Advance on Ungava Bay, and along the shoreline to the Labrador border. Mosses and lichens prevail over a vast swampy area, where only a thin layer of soil is not permanently frozen. In the more sheltered places some woody plants can grow, including dwarfed willows and shrubby birches. Bleak as it may appear, that region of 50,000 sq. miles is not a completely barren land. Over 200 species of flowering plants have been identified there. 3 Eskimo groups along the shores live almost entirely on the products of the sea. It might be possible to improve their way of life by the introduction of reindeer here as elsewhere in Northern Canada.
The great coniferous forest, known also as the Boreal forest or Taiga, extends over the most of Quebec. Its northern limit is the southern edge of the Tundra while its southern boundary runs from the northern end of Lake Timiskaming to Baskatong Reservoir and to St. Zenon in Berthier county, thence northward beyond La Tuque to include the forests of the lower part of the St. Maurice valley, thence southeast again, skirting the Laurentide Park to the shore of the St. Lawrence Estuary, north of Beaupré. Outlying patches of this forest are found on Anticosti Island, in Central Gaspé and in the highlands between the Matapedia and Temiscouata valleys. The forests of the Lake St. John Basin, however, belong in the mixed class.
Black spruce is found throughout the region. Other conifers including balsam fir, white spruce, tamarack and jack pine are of wide occurrence and characterize some sections. A few deciduous trees are present, including aspen, paper birch and, sometimes, balsam poplar. White and red pines may be found along the southern border.
The Ungava Forest
From Lake Mistassini northward lies an area of poor forest which Halliday terms the "Northeastern Transition Section". It is an open woodland composed of stunted black spruce and balsam fir with scattered birch, and jack pine interspersed with treeless moors. The surface vegetation is composed largely of white lichens. Trees of commercial size occur in sheltered valleys on the eastern side of James Bay and in the Koksoak valley far to the north.
The southern portion of the coniferous forest constitutes a large reserve of merchantable timber, the various sections of which have characteristic associations.
The Clay Belt Forest
The poor drainage of the Clay Belt favours an association with black spruce as the dominant species, mixed with tamarack and some northern white cedar. With better drainage the podzol soils carry a mixed stand of white spruce, balsam fir, white birch, aspen and balsam poplar.
The North Shore Forest
Here black spruce and balsam fir are of equal importance, jack pine and white spruce are the secondary species, associated with white birch and aspen on lake shores and bottoms of valleys. The latter species are likely to take a predominant place after forest fires. The same trees are found on Anticosti Island.
The Laurentian Forest
It extends from Lake Timiskaming to the Upper St. Maurice River and the Laurentide Park. It may be looked upon as a transition region, where climatic conditions, differences of soils and exposure of the slopes influence the vegetation. Here species are more numerous and growth is more luxuriant. Black spruce and balsam fir are dominant species, but other associates differ: white birch is dominant on high, southward facing slopes, Jack pine on the sandy terraces of the St. Maurice, white pine on sandy plain and red pine on gravel ridges. In the Laurentide park, the cool and moist climate, podzol soils and higher altitude are responsible for the typical association of black spruce and balsam fir.Gaspé and the South Shore Highlands. Surrounded by the mixed forest in lower altitudes, there are patches of the great Boreal forest on the highlands of Central Gaspé and on the South Shore of the Estuary. The heavy precipitation of Gaspé favours pure stands of black spruce and balsam fir, mixed with white spruce, aspen and white birch on slopes and valley floors. Farther south, black and white spruce become predominant, associated with balsam fir and white birch.
Higher temperatures and a longer period of vegetation are responsible for the transition from the coniferous forest of the north to the mixed coniferous and deciduous stands of this intermediate belt which extends from Lake Timiskaming to the estuary of the St. Lawrence. Because of local differences, four different sections may be described.
The Timiskaming section is the western portion of the belt. It has clay soils and relatively higher summer temperatures. The predominant tree species are black spruce and balsam fir, aspen and white birch.
The Laurentian section, besides the four species just mentioned, carries white pine, hemlock, maple, red and jack pine. Its "pineries" formed the source of much of the timber which came down the Ottawa River.
The Lake St. John and Saguenay section forms an enclave in the coniferous forest where warmer summers and more favorable soils have permitted the growth of maple, white birch and aspen among the conifers.
The St. Lawrence Estuary section, due to its proximity to the sea as well as its marine clay soils, also has a favorable environment. Here additional broad leaved species such as black ash, balsam poplar and white elm are found with the conifers. Here, also, is found the northern range of the white cedar.
Hardwood Forest Region
In the warmest regions of Quebec, the St. Lawrence and Ottawa Valleys and the Eastern Townships, hardwoods are predominant. Before it was cut for the purpose of settlement, the virgin forest was the finest in Quebec and included a great variety of species: white and yellow birch, sugar and red maple, aspen, associated with white pine (the best timber tree of Eastern Canada), balsam fir, hemlock and white spruce. Species of a warmer climate are to be noted also, such as red oak, beech, white ash, butternut, cottonwood and balsam poplar. Rare species in the upper St. Lawrence are basswood and rock elm.