In general, the target would be set by the sustained yield principle. Several countries have calculated their total annual allowable cut, or total annual increment, and their total annual removals. Targets still need to be established for tropical forests. Countries are supported to maintain or increase their forested areas, and discouraged to strongly reduce their forest lands. Concepts and definitions are generally available for developed countries, and for all countries in the case of plantations.
Additional work is required to determine the natural increment concept for tropical forests.
Annual Roundwood Production includes all wood obtained from removals from forest and from trees outside the forest. FAO statistics include recorded volumes as well as estimated unrecorded volumes. Forest Growing Stock means the above-ground volume of all living standing trees down to a stated minimum diameter. Total Annual Increment represents the total annual increment of wood due to the growth of the trees during a year. The enumerator is the total annual roundwood production.