THE VEGETATION OF NORTHERN MANITOBA: I. STUDIES IN THE SOUTHERN SPRUCE FOREST ZONE
It is pointed out that there are available no ecological accounts of the vegetation of Northern Manitoba and the surrounding regions. After brief accounts of the topography, geology, and climate, the communities which were met with in two areas of study are described. It is shown that the predominant and stable forest of mesic sites is dominated by Picea mariana, with a ground vegetation composed chiefly of weft-form mosses. In areas which have been burned various subseral variants of this forest are present. Pinus banksiana, as well as being a seral dominant of mesic sites, dominates various forests of outcrop ridges, sand plains, and eskers. Picea glauca is rare in the area, occurring only on those sites which show exceptionally favourable conditions of habitat. The vegetation of this region conforms with descriptions of the Southern Spruce Forest Zone of Eastern Canada, which classification might well be extended westwards at least as far as northwest Manitoba. There is some evidence that the dry climate which prevails west of the region, and for which there is slight evidence here, has influenced the flora and vegetation of the region. A description is given of a highly local community of Betula papyrifera var. neoalaskana on organic ridges which appears never to have been recorded previously for North America.