THE STORY OF A CUT-OVER

1. A considerable part of the mixed white spruce—trembling aspen stands in Saskatchewan appears to be forming itself in a cyclic process. After a fire, when poplar has established itself, the first wave of spruce comes in; the second follows in about 50 to 70 years. When the trembling aspen thins itself, the crest of the third wave comes and, together with the remaining apsen, the spruce of the first wave starts to deteriorate.2. This cyclic development of such stands seems to provide an opportunity to apply management on the basis of a permanent forest.3. Cutting by diameter limit in such stands results in windthrow and die-off, exceeding the increment of the residual white spruce.4. Crown quality is a decisive factor with white spruce in its response to release in these mixed stands.5. White spruce in these mixed stands responds to release even at the age of 100 years.6. Insufficient regeneration of white spruce in the examined area appears to be due to lack of seed; heavy sod, invasion of shrubs and weeds seem to be main obstacles to regeneration.