Intensive management influence on Douglas-fir stem form, branch characteristics, and simulated product recovery

Abstract

Intensive management may adversely affect lumber yield and quality by increasing knot size and creating a more conical stem form with a greater average rate of taper. This study was initiated to examine the impact of management on simulated lumber yield and quality. Stem diameter and branch size and location of 223 Pseudotsuga menziesii (Mirb.) Franco (Douglas fir) stems ranging in age from 5 to 65 years and from a wide variety of stand conditions were intensively measured. Stand conditions included varying levels of vegetation management, precommercial thinning, commercial thinning, fertiliser application, and severity of infection by Phaeocryptopus gaeumannii (Rohde) Petrak (Swiss needle cast). In addition, 86 virtual logs were created and processed by AUTOSAW. Significant changes in both stem form and branch characteristics were observed among the stand conditions examined, with maximum branch size being the most