Abstract
This report summarizes the results of a retrospective study of post-harvest conditions in the Kootenay variant of the Interior Douglas-Fir Dry Mild biogeoclimatic subzone (IDFdm2) in the Rocky Mountain Trench of the Nelson Forest Region. The 22 stands in the study were harvested by partial cutting methods between 1982 and 1992. The study, initiated in 1998, was undertaken to assist forest managers in preparing forest development plans that, increasingly, include partial cutting.
The objectives of the study were to:
1) Evaluate the success of advanced and post-harvest natural regeneration.
2) Evaluate the effects of overstory and site conditions, and relate them to regeneration success.
3) Assess early stand development and release of the residual stand.
Generally, with the exception of droughty south-facing slopes, these stands are well stocked. Post-harvest natural regeneration (counting only Layer 4 stems) was generally abundant, ranging from 189 to 5067 stems/ha. The understory species composition reflected that of the remaining overstory species composition within 3%.
There was no significant correlation between basal area retained and numbers of germinants. However, together, shrub cover, slash cover, and residual stems/ha accounted for 54% of the variation in germinants.
Harvesting removed 13 to 70% of the pre-harvest basal area. Post-harvest basal area growth averaged 0.31 m2/ha/yr, and the stands assessed are expected to take between 11 and 90 years to recover to their respective pre-harvest basal areas.
The silviculture prescriptions for most of the study stands specified salvaging lodgepole pine due to mountain pine beetle infestation. As such, the stands were not planned as partial cuts. Since that time, the Forest Practices Code of British Columbia has been enacted. Therefore, the authors suggest that the findings from this study may not be representative of current harvesting or silvicultural practices.
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Updated April 12, 2007
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