Canadian Forest Service Publications
Silvicultural and harvesting options to favor immature white spruce and aspen regeneration in boreal mixedwoods. 1994. Navratil, S.; Brace, L.G.; Sauder, E.A.; Lux, S.J. Natural Resources Canada, Canadian Forest Service, Northwest Region, Northern Forestry Centre, Edmonton, Alberta. Information Report NOR-X-337.
Issued by: Northern Forestry Centre
Catalog ID: 11979
Availability: PDF (download)
Two sequential projects were implemented in boreal mixedwoods in Alberta. Project 1480, initiated in 1988, tested the planning and application of silvicultural and harvesting systems designed to protect immature (understory) white spruce during the harvest of aspen overstory, realize the growth potential of residual spruce, and encourage aspen regeneration. Silvicultural prescriptions were based on a two-stage harvesting and tending stand level model. Results show that, using conventional harvesting equipment, and with adequate planning, crew training, and supervision, 50–60% of spruce understory trees can be protected during the harvest of overstory deciduous trees; most wind damage will occur in the first 3 post-harvest years. Five years after the first-stage harvest, spruce growth shows significant height, diameter, and volume response, and aspen regeneration is adequate. The potential yield in 60 years from a second harvest of spruce and aspen seems promising. Project 8032, initiated in 1992, tested the effectiveness of a range of silvicultural and harvesting systems in reducing wind damage to residual spruce on moist-to-wet sites after harvest of the deciduous overstory. The project includes studies of harvesting costs, productivity, mixedwood growth and yield, aspen regeneration, wind damage, and wind behavior within cutblocks. Initial results show that the silvicultural systems and cutblock designs implemented provide a range of residual spruce wind protection and that, using conventional roadside equipment, a variety of silvicultural options can be achieved.