STRUCTURE AND GROWTH OF BLACK-SPRUCE STANDS ORIGINATING FROM ADVANCE GROWTH, 40 YEARS AFTER CUTTING IN LAC-SAINT-JEAN, QUEBEC

Age, height and diameter distribution as well as height and diameter growth were studied in ten mesic black spruce stands originating from advance growth, forty years after cutting. All sampled stands showed a negative exponential type age structure. The majority of the trees were of layer origin established in the mature stands that were cut in the 1930's or 1940's. The sampled trees were generally distributed among numerous height and diameter classes. According to stem analysis, the ten sampled stands can be separated into two distinct groups based on their height growth performance, following the drainage pattern. Mean annual height and diameter increments were comparable to those described in yield tables for natural black spruce stands. Sites with adequate stocking and density should thus give good volumes. Stands of advance growth origin have the advantage of possessing some trees with a certain height immediately after the cutting. However, they are generally highly variable in diameter and height classes which can be an inconvenience in wood processing.