Pruning Wounds and Occlusion: A Long-Standing Conundrum in Forestry

The proper method for branch removal is a long-standing question in forestry. If the branch is cut flush with the stem, a larger wound results, but if the branch is cut further from the stem, the resultant clearwood production will be less. Both alternatives have implications for tree health and wood quality. A long, international history of forest pruning research generally indicates that a cut parallel and close to the stem will maximize clearwood production without excessive stem decay. Some exceptions exist for species where potential for stem decay is high. The method recommended in most guidelines for all types of pruning is an outside branch collar approach based primarily on a small number of observational studies. However, maintaining tree health and maximizing clearwood production are not mutually exclusive and a cut close to the stem can meet both objectives. Alternative approaches to branch removal may be useful for other objectives.