In the north-eastern portions of the ecozone, the underlying Precambrian rock is usually mantled with a thin layer of glacial till but diverse assemblages of saxicolous (i.e., rockdwelling) lichens are able to colonize the glacial erratics and churned boulder fields common in upland sites (Figure 6). Figure 6. Crustose lichens on boulders near Misaw Lake, SK. Photo courtesy of Robert A. Wright. Bedrock outcroppings are more common south and west in the ecozone and support rich growths of Cladonia (Reindeer lichens) and Stereocaulon (Figure 7). Figure 7. Cladonia spp., and crustose lichens growing with goldenrod (Solidago missouriensis), sage (Artemisia biennis), three-toothed saxifrage (Saxifraga tricuspidata) and a fern (Woodsia ilvensis) on a granitic outcrop, southwest shore of Tazin Lake, SK. Photo courtesy of Robert A. Wright.
Boreal Shield. Forests increase in stature and floristic diversity as one moves southward into the Boreal Shield. Jack pine stands (Figure 8) become as common as Figure 8. Cladonia arbuscula subspecies mitis with a minor component of C. stellaris on a sand-veneered rock knob at Pink Lake, SK. Photo courtesy of Robert A. Wright. black spruce (Figure 9) in upland positions. Lichen woodland is still common but these Figure 9. Black spruce lichen woodland near Wollaston Lake, SK. Photo courtesy of Robert A. Wright.