Abstract A study of forest stand production was carried out in natural 40-year-old balsam fir—white spruce—white birch stands of 700, 1000, 1500, 2000, 3000, and 5000 stems per acre in northwestern New Brunswick. A total of 101 fir, 14 spruce, 24 birch and a pin cherry were felled and analyzed to determine the distribution of dry matter among foliage, cones, stem wood, stem bark, branch wood and branch bark. The standing crop and annual increment per acre were found to increase with increasing stand density throughout the density range examined.