The Columbia Forest Region
The Columbia Forest is influenced by a belt of higher rainfall in the Selkirk and Monashee Mountains. It has some of the characteristics of the coastal forest but exhibits many of the features of its neighbours, the Montane forest and the Subalpine forest. The most important species are Engelmann spruce, western red cedar, western hemlock and Douglas fir. Western white pine, western larch and grand fir occur in the southern section. Lodgepole pine comes in after fires. Black cottonwood is common on river bottoms.
The Montane Forest Region
The Montane Forest is found in the southern interior of British Columbia, often known as the Dry Belt. It occupies the plateaux and slopes as far north as the Skeena river but in the lowest and driest valleys gives way to open grassland. The outstanding tree of this region is the yellow or ponderosa pine (Pinus ponderosa). Toward the north however, ponderosa pine gives way to an association of Douglas fir and lodgepole pine while toward the northeast there is considerable admixture of Engelmann spruce and alpine fir. Aspen is important, also, toward the north. The most typical montane landscape however, is a scattered parklike stand of ponderosa pine amidst a steppe vegetation of bunch grass (Agropyron spicatum), spear grass (Stipa columbiana), balsam root (Balsamorrhiza sagittata), wild rose (Rosa nutkana), coral berry (Symphoricarpos racemosus) and, where overgrazed, wormwood (Artemisia frigida), yarrow (Achillea millefolium) and mullein (Verbascum thapsus).
The Rocky Mountain Forest Region
This elongated but complex area comprises the subalpine forests of the foothills and lower mountain slopes from three thousand feet to the tree line. Beyond this are the alpine tundra and the areas of perpetual snow which cannot be differentiated on our small scale map. The dominant species are Engelmann spruce (Picea Engelmanni) and alpine fir (Abies lasiocarpa) while lodgepole pine and aspen comprise a sub-climax. Toward the south alpine larch (Larix Lyallii) and whitebark pine (Pinus albicaulis) are found.
Many of the plants of the alpine tundra are the same as those of the Arctic, others however are found only in the Cordilleran region, including alpine willow (Salix nivalis), red heather (Phyllodoce empetriformis), moss heather (Cassiope Mertensiana), alpine hairgrass (Deschampsia alpicola) white marsh-marigold (Caltha leptosepala) and mountain pink (Douglasia nivalis).