Effect of seed cutting and germination substrate on rich second growth balsam fir stand regeneration in Quebec

Stand regeneration failures, sometimes observed in rich second growth balsam fir stands, prompted a study in 1991 to assess the effects of the shelterwood cutting system on regeneration of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss) and paper birch (Betula papyrifera Marsh). The factorial experiment design (split-plot) includes forest cover reduction (0% and 2.5% of basal area) in main plots and germination substrate (mineral soil, litter removed and control) in subplots. Results of five growing seasons showed that germination substrate was the main factor determining first-year seedling establishment, and that cover reduction became important for seedling survival and long-term establishment of the three species. A 25% canopy reduction combined with mineral seedbed treatment resulted in the best regeneration densities of the three species. Thus far, the results demonstrate the importance of combining humus disturbance to seed cutting in order to achieve regeneration goals set for the future stand.