Precommercial thinning in a northern conifer stand: 18-year results

Four levels of precommercial thinning were applied with and without fertilization in a young, even-aged stand of northern conifers in east-central Maine. After 18 years, precommercial thinning resulted in longer and wider crowns and greater survival, growth, and yield of selected crop trees compared to untreated controls. Growth and yield were greater with uniform spacing at approximately 2.4 × 2.4 m and 1.5-m row thinning with crop-tree release in residual strips than with row thinning without crop-tree release. Control of stand species composition was greatest with uniform spacing. Fertilization had no significant effect.