The majority of the coastal forest at low to medium elevations is dominated by western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata), with Douglas-fir (Pseudotsuga menziesii) abundant in the south and amabilis fir (Abies amabilis) and Sitka spruce (Picea sitchensis) abundant in the north. Arbutus (Arbutus menziesii) — a broad-leaved evergreen tree — typically joins Douglas-fir in much of the drier forest near the sea in the Strait of Georgia region. Shore pine (Pinus contorta var. contorta) can be found in very wet, boggy forests or on very dry areas such as rock outcrops. Mountain hemlock (Tsuga mertensiana), amabilis fir, and, to a lesser extent, yellow-cedar (Chamaecyparis nootkatensis) predominate in the coastal subalpine forest.
Ponderosa pine (Pinus ponderosa) and Douglas-fir dominate the dry forest, parkland and savanna of the southern Interior. Western larch (Larix occidentalis), a deciduous conifer, is a common associate of these in southeastern British Columbia.
Lodgepole pine (Pinus contorta var. latifolia) and Douglas-fir form extensive stands over much of the southern half of the Interior Plateau. Douglas-fir gradually drops out from the northern half, where white spruce (Picea glauca), hybrid white spruce (P. engelmannii x glauca) and subalpine fir (Abies lasiocarpa) join lodgepole pine as the dominant conifers.
The wetter parts of the Columbia and southern Rocky mountains region are occupied by forests of western hemlock and western redcedar, with admixtures of western white pine (Pinus monticola), Douglas-fir, western larch, grand fir (Abies grandis), Engelmann spruce (Picea engelmannii), hybrid white spruce and subalpine fir.
The upper elevation forest and parkland of the southern two-thirds of interior B.C. consist primarily of mixtures of Engelmann spruce, subalpine fir and lodgepole pine, with whitebark pine (Pinus albicaulis) fairly common on drier sites. Subalpine larch (Larix lyallii), another deciduous conifer, is sometimes present.
The low and middle elevation forest of northern British Columbia is boreal in character and dominated by white spruce, black spruce (Picea mariana) and lodgepole pine. Northern subalpine forest consists primarily of white spruce and subalpine fir.
Trembling aspen (Populus tremuloides) is the most widespread and abundant deciduous tree species in British Columbia. Aspen stands (which may occur as closed forest or in parkland) are abundant throughout the Interior Plateau and in the boreal forest region, but are less frequent in wetter parts of southeastern B.C. and at higher elevations and are uncommon along the coast.
Red alder (Alnus rubra) is a fast-growing pioneer species that forms dense stands on much cut-over or otherwise disturbed land all along the coast.
Black cottonwood (Populus balsamifera ssp. trichocarpa) commonly forms alluvial forests throughout the province, except on the outer coast. Balsam poplar (P. balsamifera ssp. balsamifera) largely replaces black cottonwood in northern British Columbia.
Paper birch (Betula papyrifera) is widespread in the Interior but seldom dominates extensive stands. It usually occurs in mixture with conifers and other deciduous trees.
Bigleaf maple (Acer macrophyllum) is common in second-growth forest in southwestern British Columbia, but rarely dominates stands.
Garry oak (Quercus garryana) is virtually restricted to southeastern Vancouver Island and adjacent Gulf Islands, where it forms a distinctive type of deciduous forest and parkland or savanna.
Scrub is also dominant at high elevations throughout the province. Willows form subalpine and alpine scrub over much of the Interior; scrub birch often occurs with willows, especially in the north. Species of Vaccinium form high-elevation scrub, especially on coastal and snowier interior mountains. Slide tracks and some north coastal alpine communities are dominated by Sitka alder (Alnus crispa ssp. sinuata). Dwarf scrub is another widespread, abundant form of high-elevation vegetation. Dwarf scrubs — evergreen-leaved (such as mountain-heathers [Cassiope and Phyllodoce spp.]), mountain-avens (Empetrum nigrum, Dryas spp.) or deciduous (Salix spp., Vaccinium spp.) — dominate many subalpine and alpine heath and tundra communities.
Elsewhere in the province scrub can be extensive or (more often) localized, and usually develops after fire or as wetland vegetation.
Grasslands dominated by bunchgrasses, other grasses and shrubs occur in valley bottoms and on several plateaus in south-central B.C., from the Riske Creek area in the Chilcotin Forest District south to the Canada–U.S. border. Similar grasslands occupy smaller areas in southeastern British Columbia. Bluebunch wheatgrass (Agropyron spicatum) is the most widespread and dominant species. Other abundant or frequent species include rough fescue (Festuca scabrella), Idaho fescue (F. idahoensis), Sandberg’s bluegrass (Poa sandbergii), junegrass (Koeleria macrantha), cheatgrass (Bromus tectorum), needle-and-thread grass (Stipa comata), spreading needlegrass (S. richardsonii), porcupine grass (S. spartea), Kentucky bluegrass (P. pratensis), big sagebrush, pasture sage (Artemisia frigida) and rabbit-brush (Chrysothamnus nauseosus).
The drier, rainshadow areas of southwestern B.C. have small pockets of grassland (usually on warm, rocky, south-facing slopes) and are associated with dry Douglas-fir, arbutus and Garry oak woodland. These vernal grasslands are dominated by annual species of bromegrass (Bromus), fescue (Vulpia) and hairgrass (Aira). They include many introduced species as well as showy, spring-flowering forbs and are closely related to the annual grasslands of Oregon and California.
In the northern two-thirds of the province, lower elevation grasslands are usually localized and restricted to steep, south-facing slopes. Some typical species are slender wheatgrass (Agropyron trachycaulum), Altai fescue (Festuca altaica), purple reedgrass (Calamagrostis purpurascens), spreading needlegrass, stiff needlegrass (Stipa occidentalis var. minor), fuzzy-spiked wildrye (Elymus innovatus), glaucous bluegrass (Poa glauca), pasture sage and northern wormwood (Artemisia campestris).
High-elevation grass vegetation occurs throughout the province in the drier alpine areas. Dominant grasses vary from south to north, but include rough fescue, green fescue (Festuca viridula), Altai fescue, alpine fescue (F. brachyphylla), arctic bluegrass (Poa arctica), alpine sweetgrass (Hierochloe alpina) and purple reedgrass. Species of the sedge family often dominate or codominate the vegetation. Some typical species are dunhead sedge (Carex phaeocephala), showy sedge (C. spectibilis), short-stalked sedge (C. podocarpa), small-awned sedge (C. microchaeta), spikenard sedge (C. nardina), two-toned sedge (C. albonigra), blunt sedge (C. obtusata), single-spiked sedge (C. scirpoidea ssp. pseudoscirpoidea), capitate sedge (C. capitata) and Bellard’s kobresia (Kobresia myosuroides).
Wetland grass types include several different kinds of marsh and fen vegetation. Freshwater marshes and fens are usually dominated by sedges or grasses. Some typical species include water sedge (Carex aquatilis), beaked sedge (C. rostrata), inflated sedge (C. vesicaria), black alpine sedge (C. nigricans), great bulrush (Scirpus lacustris), tufted clubrush (Trichophorum caespitosum), reed canarygrass (Phalaris arundinacea) and common reed (Phragmites communis), among many others. Coastal saline marshes are frequent but usually not extensive; their most characteristic dominant species are Lyngbye’s sedge (Carex lyngbyei) and tufted hairgrass (Deschampsia cespitosa). Alkaline marches occur in the dry southern Interior and have species such as alkali saltgrass (Distichlis stricta), alkali muhly (Muehlenbergia asperifolia), foxtail barley (Hordeum jubatum), wire rush (Juncus balticus), bulrushes (Scirpus spp.), European glasswort (Salicornia europaea) and seablite (Suaeda depressa).
Seasonal herb meadows also occur locally in the Strait of Georgia region, in some openings in the dry forest of the southern Interior and in recently clearcut or burned openings.
