Dynamics of the Lac Edouard experimental forest after partial clearing at Maurice National Park (Quebec)

Forest dynamics following a partial cut conducted in the early 1950s in the Lac Edouard Experimental Forest in the Mauricie National Park, Quebec, Canada, were studied. Changes in vegetation were analyzed for the period between 1946 and 2001 in 109 mesic stands of the sugar maple - yellow birch bioclimatic domain. Three cutting intensities were considered: 1) low intensity, 15-30% of the basal area; 2) moderate intensity, 30-45% of the basal area; and 3) uncut. More than fifty years following cutting, the original relative proportion of the deciduous and softwood species was maintained. The relative proportion of basal area occupied by softwood species relative to the total basal area varied only from 2.0% to 7.4%. Red spruce (Picea rubens Sarg.) basal area increased in forest types Cornus (Co) and Oxalis-Cornus (O-Co) whereas balsam fir basal area decreased. In the Viburnum-Oxalis (Vi-O) forest type, sugar maple (Acer saccharum Marsh.) basal area increased and yellow birch (Betula alleghaniensis Britt.) decreased. Cutting areas were not invaded by competition species such as mountain maple (Acer spicatum Lamb.). In the Co and O-Co forest types, the regeneration density is probably sufficient to maintain the current cover type. In the Vi-O forest type, where moderate partial cutting was conducted, the deciduous component could substantially increase. Stands reacted positively to partial cutting. The increased growth of residual stems and the arrival of new stems resulted in 2001 total basal areas that were equal to or larger than those observed before cutting (1946).