The vegetation of the Canadian Prairie Provinces IV. The woody vegetation, Part 2 Wetland shrubbery
In this paper shrubbery occurring on soils with the water table close to the surface, or permanently wet, is described. Two main types of wetland shrubbery can be distinguished. The one type is characterised by the dominance, or codominance, of Salix spp., and can be classified with Eurasian willow communities in a class-group Betulo-Salicea. Two classes, three orders, 5 alliances, 11 associations, and 10 variants are described in the willow communities. The second wetland shrubbery is dominated by ericaceous shrubs, and can be placed in the class Oxycocco-Sphagnetea, with the order Sphagnetalia fusci (Tx. 1955) em. 1970, and the two alliances Ledo palustris-Sphagnion fusci in western North America, and Kalmio-Sphagnion fusci in eastern Canada. Three associations are described for the Prairie Provinces, and their ecology and distribution are discussed.