Phytoecological Study of Sylvotundra at Small Tree Lake, N.W.T.

Abstract

Attempts to make a quantitative evaluation of representative plant communities in relation to physiographic features in the central part of North American sylvotundra (the ecotone between treeless tundra and the taiga). Lake shores and hill-bottoms support closed canopy Picea mariana forest, but the exposed slopes are treeless. A Picea glauca parkland forms a transition between forests and treeless slopes. Analysis of the vegetation by strata, viz: ground cover, low herbs and decumbent shrubs, and tall herbs, tall shrubs and arboreal seedlings, showed decrease of cover as level above ground increased. Along a gradient from forests to treeless shapes, the percentage of boreal plants decreased and that of the arctic plants increased. The present forest-tundra boundaries at Small Tree Lake appear semi-permanent.