Influence of Spacing and Artificial Pruning on the Production of Clearwood of Douglas-fir

This document explores the economic and biological feasibility of managing second-growth Douglas-fir forests to ensure a future supply of high-quality clearwood. As old-growth harvests decline, the author uses field research and a specialized simulation model named PRUNE to examine how different initial spacing and artificial pruning techniques impact tree growth, branch diameter, and overall wood value. The document provides an extensive analysis of market trends and price structures in British Columbia, suggesting that early pruning of widely spaced trees offers the most promising return on investment for intensive forest management. This research can support foresters in optimizing the production of knot-free timber by balancing the costs of silvicultural interventions against the premium prices paid for superior wood grades.