Variations in longitudinal permeability of coastal western hemlock

摘要

The air permeability of western hemlock from coastal forests in western Oregon was assessed. Permeability varied widely among trees, as well as by position within individual trees. Permeability tended to decrease with distance inward from the bark, a trend implying that this species produces a heartwood zone. These variations may help to explain the treatability differences observed in lumber of this species.