DBH – The diameter of a tree stem at breast height (4.5 feet) above the ground. DIB (d.i.b.)– Diameter inside bark. Diameter of a log at its small end, measured inside the bark.
Deciduous tree – A tree that loses its leaves during the winter.
Defect – The portion of a tree or log that is unusable for the intended product. Examples are decay, crook, and excessive limbiness.
Diameter – See DBH or DIB.
Diameter class – A tree stem diameter category that may include 1 or more inches of diameter.
Direct seeding – See seeding.
Dominant – See crown classification.
Duff – Undecomposed organic matter (such as leaves, twigs, moss, pieces of bark and wood) that litters a forest floor.