Canadian Forest Service Publications
Stand development after partial cutting of mature mixed stands of white spruce and aspen in Manitoba. 1997. Ball, W.J.; Walker, N.R. Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta. Information Report NOR-X-353.
Issued by: Northern Forestry Centre
Catalog ID: 11579
One-hundred-year-old mixed white spruce–aspen stands were partially cut in 1953, 1954, and 1955 and scarified leaving treatments that retained 14–100% of total stand basal area. Composition of the stands based on measurements of 88 (0.081-ha) permanent sample plots before and after cutting, and in 1992, is described. Mortality assessments in 1960 showed that all levels of partial cutting resulted in acceptable residual stand losses during the early establishment period. Residual white spruce mortality, 5–7 years after logging and scarification treatments, ranged from 6–7% on non-cut controls to 23% on heaviest cut treatments. On treatments where hardwoods were not cut, hardwood mortality ranged from 2 to 3% over the same period. Development and decline of the partially cut stands are described in terms of residual trees, snags, and windfalls in 1992. Development of softwood regeneration and hardwood reproduction is also described. Basal area of 37-year-old hardwood reproduction increased with cutting intensity and ranged from 1.1 to 16.1 m2/ha, exceeding original hardwood basal area on the two heaviest cut treatments. Numbers of suckers increased from 131–420 stems/ha on treatments where hardwoods were not cut to 170–1368 stems/ha on treatments where all hardwoods were cut. White spruce regeneration was 10 times more abundant on scarified seedbeds and better beneath residual hardwoods than under hardwood reproduction that developed on hardwood-cut treatments. Both hardwood reproduction and natural white spruce regeneration increased sharply as residual white spruce was reduced to 4.4 m2/ha. Options for renewing mature mixedwood stands are discussed.