Two major types of taiga vegetation predominate throughout the plains. The closed forest consists of many closely spaced trees with mossy ground cover and lichen woodland, with trees that are spaced further apart and have a lichen ground cover. The later is more common in the northern boundary of the taiga. The predominant trees in the Taiga are conifers, or needle bearing trees. The spruce, pine and larch or tamarack are the most numerous. These evergreen species are well adapted to life in the taiga with adaptations that allow them to with stand the harsh winter conditions, although larch, the most cold tolerant of all trees, is deciduous. Taiga trees often have shallow roots to take advantage of thin soil layers. The slim, conical shape of the northern conifers and their downward drooping limbs also help them shed snow. The sun is low on the horizon for most of the year in this ecoregion and for that reason it difficult for plants to generate energy from photosynthesis. Pine and spruce are adapted well for this lack of sunshine and are able to photosynthesize with older leaves in late winter and early spring when light is sufficient but temperatures are too low to produce new growth. Evergreen needles lose less water to the air than broad-leaved plants and their dark colors increases their absorption of light and heat.

Northern Great Bear Plains HS (High Subarctic) Ecoregion

White spruce communities are the most common vegetation types; the species composition of white spruce communities is fairly consistent across the Ecoregion, but progressively more rigorous climates at higher latitudes result in reduced tree height and density, culminating in the transition to shrub-dominated tundra along a broad, poorly defined boundary with the Southern Arctic Ecoregion. Extensive fires have resulted in large areas of regenerating dwarf birch. Treeless lichen-dwarf birch communities cover polygonal peat plateaus. Jack pine does not occur in this Ecoregion; trembling aspen does occur, but only as stunted individuals on south-facing slopes and well-drained alluvial terraces.

Central Great Bear Plains LS (Low Subarctic) Ecoregion

Typical landscapes in the Central Great Bear Plains Low Subarctic (LS) Ecoregion are a mosaic of uplands and wetlands. In the colder northern part of the Ecoregion shown in the photo, semi-closed to open upland stands of black spruce with understories of dwarf birch, northern and common Labrador tea, moss and reindeer lichen are interspersed with treed or shrubby bogs and marshlands. Open white spruce and birch stands with discontinuous understories of red bearberry and mountain cranberry and lichens are often found on drier sites. Warmer conditions to the south promote the development of white spruce, paper birch and aspen forests on moist sites; jack pine dominated stands are common on well-drained sandy or gravelly soils.

Great Slave Uplands HB (High Boreal) Ecoregion

Typical upland landscapes in the Great Slave Uplands High Boreal (HB) Ecoregion are forested by closed to semi-closed stands of mostly black spruce and pine with some paper birch and understories of feather moss, mountain cranberry, alpine bilberry, common Labrador tea, and lichen. White spruce and aspen mixed-wood stands occur on warm, moist well-drained sites. On drier sites mixed, open stands of black spruce and jack pine are widespread. Bog and marshland complexes consisting of black spruce, common Labrador tea, alpine bilberry, bog rosemary, cloudberry, sedges and peat mosses dominate cold, wet, poorly drained sites. Shore marsh wetlands are common but are not as extensive as those in the warmer Mackenzie and Slave Lowlands MB Ecoregion.

Mackenzie and Slave Lowlands MB (Mid-Boreal) Ecoregion

Mixed-wood forests of aspen, balsam poplar, white spruce and occasionally paper birch, containing diverse herb and shrub understories, are typical of landscapes in the Mackenzie and Slave Lowlands Mid-Boreal (MB) Ecoregion. White spruce, herbs and feather mosses characterize these stands. Dense to open stands of jack pine, often in combination with shorter, slower-growing black spruce, occur extensively on dry, sandy to gravelly sites. Expanses of flat, poorly drained terrain result in extensive bog and marshland development throughout the Ecoregion. Black spruce, larch (in marshlands), Labrador tea, mountain cranberry, leather leaf, sedges, mosses and reindeer lichen dominate these cold, wet, poorly drained sites. Lush sedge, grass and willow marshlands associated with stream floodplains and lakeshores are common.