Young Stand Development in Coastal Western Hemlock as Influenced by Three Harvesting Regimes

Growth patterns of naturally regenerated western hemlock ( Tsuga heterophylla [Raf.] Sarg.) were studied by stem analysis following partial cutting of a dense, second-growth stand on the Washington coast. Three partial cutting densities comparable to thinning, shelterwood cutting, and seed-tree cutting were established when the stand was 60 years old; final overstory removal occurred 8 years after the initial cut (and 4 years after an intermediate cut) in all treatments. Stocking resulting from each treatment was similar and excessive, and ranged from 12,400 to 212,500 stems per hectare. It consisted predominantly of trees established between the initial and final cuts. Eight years after the final harvest cut, heights, ages, and diameters of dominants in the regenerated stand were greatest in the light (most open) treatment; trees were shorter, younger, and smaller in diameter with progressively denser overstory treatments. Although rather different in present appearance, the young stands followed similar patterns of canopy differentiation, dominant height growth, and dominance assertion after the final overstory removal. The dominant stems consistently asserted themselves over other stems after 2 meters height. Forest Sci. 30: 117-124.