THE VEGETATION OF NORTHERN MANITOBA: VI. THE LOWER HAYES RIVER REGION

• Published in: Canadian Journal of Botany
• Main Author: Ritchie, J. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1960
• Subjects: Plant Science; Canada; Hayes; Hudson; Hudson Bay; Hayes River; palsa; Subarctic
• Online Access: http://dx.doi.org/10.1139/b60-067; http://www.nrcresearchpress.com/doi/pdf/10.1139/b60-067

The vegetation of the Hudson Bay Lowlands of Canada is known only in the most superficial terms. This contribution provides descriptions of the chief cover types of a small portion of the Lowlands near the confluence of the Hayes and Nelson rivers. The area has a continental, subarctic climate. Postglacial marine inundation has deposited thick calcareous clays; the topography is flat.On the mineral substrata of alluvial and marine deposits the chief types of vegetation are salt marsh, shrub (dominated by Salix species), forests of Populus balsamifera, and forests of Picea glauca. They often form discrete zones in the order mentioned, and it is likely that this is a seral as well as spatial relationship. On the extensive peat substrata there are bog and fen types. In the former are distinguished two communities dominated by Picea mariana—one, termed lichen muskeg, with a ground layer of Cladonia and Ledum, and the other, moss muskeg, with Pleurozium and Ledum groenlandicum as ground layer dominants. Locally, areas of lichen muskeg have been destroyed by fire and are now occupied by willow communities. In wet inland areas, moss muskeg and lichen muskeg communities are associated with palsa and string-bog features. On shallower peats, usually nearer the shores and rivers, fens predominate, with Larix laricina and Betula glandulosa as the dominant phanerophytes.All these types have been distinguished on vertical aerial photographs, and their photographic characteristics are summarized. A detailed vegetation map illustrates their chorology.