As young-growth forests replace old-growth forests as the primary source of Douglas-fir raw material, the technique of managing young stands becomes increasingly important. Managers of young-growth timber need to know whether it is economical and silviculturally feasible to make thinnings in stands that are close to rotation age. Final harvest of some stands of this age might be delayed for perhaps two decades if in the meantime some income could be obtained from them in the form of thinnings.
Steele, Robert W. 1954. Two commercial thinnings in century-old Douglas-fir. PNW Old Series Research Notes No. 97, p. 1-5