Forecasting the partial cutting cycle for Québec yellow birch-conifer mixedwood stands

Since the mid 1990s, partial cuts have been widely used in yellow birch–conifer stands (BJR, bétulaies jaunes résineuses) in the temperate forests of Québec. We studied the impact of residual basal area on stand composition and on the time required to reconstitute enough merchantable basal area to allow for a second partial cut, according to the usual standards of forest management in Québec. To do so, we used a dataset from 9 experiments as well as simulations of the Artémis-2014 growth model and those of a new model, BJR, which we calibrated using the study data. Our results show that residual basal area influences stand periodic annual increment, which peaks 10 to 15 years after the cut. Residual basal area also influences the length of the cutting cycle and future stand composition. We estimated a mean cutting cycle of 24 years for a mean residual basal area of 18 m 2 ·ha -1 , and of 40 years for a mean residual basal area of 14 m 2 ·ha -1 . For the latter, our results also show that some opportunistic species of lesser commercial value, such as red maple, could become more abundant.