L'état actuel des vieilles sapinières à Hylocomium à la forêt Montmorency de l'Université Laval

The present status of old balsam fir stands (Hylocomium-Oxalis site-type) has been studied on sites of second quality (index of 40 feet at 50 years) by means of 1/5-acre random sample plots. Comparisons with normal yield tables indicate that, between the age of 70 and 90 years, these stands show 1) too many stems per acre, mainly due to abundant ingrowth, 2) a constant average stand, d.b.h., 3) a loss of 30 sq.ft. per acre of basal area, and 4) a reduction of the mean annual increment in merchantable volume from 33 to 22 cu.ft. per acre.It is concluded that these site class II balsam fir stands are already mature, rapidly deteriorating, and failing to occupy the station fully. Consequently, they should be managed on rotations shorter than 70 years. Thinnings might be conducted 15 years before the final cutting to salvage otherwise heavy losses by natural mortality.