Directional felling -Predetermining the way a tree will land when it hits the ground. When shears are used, the wedge-shaped blade provides a lever that directs the tree into its lay. Direct seeding -Spreading seed s over the forest seedbed by hand or machine. Discounted cash flow -In evaluating investment opportunities, the various costs and benefits anticipated in future years discounted to the present. Disturbance - A natural or human induced environmental change that alters one or more of the floral, faunal, and microbial communities within the ecosystem.
Timber harvesting is the most common disturbance.
Windstorms and fire are examples of natural disturbance. Dock -See landing . Dominant trees -The most numerous and vigorous species in a mixed forest. Donkey -Also known as a yarder. May be designated by the special use to which it is put, such as yarding, skidding, roading, or loading.