Predicting pruned branch stub occlusion in young, coastal Douglas-fir

Abstract

Time is required after pruning tree branches until radial stem growth occludes individual branch stubs. Foresters and planners need improved understanding of factors affecting occlusion time and distance so they can better forecast yield of clear wood and returns on pruning investments. This study examined occlusion of 335 pruned branches from 38 coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees sampled from 13 stands that were pruned between age 9 and 22. Regression models were developed for predicting number of years to occlude, the width of the occlusion region, and radius-over-occlusion which is the distance from the stem pith to the onset of clear wood production. Study results indicate that years to occlude is a function of stem size, stub length. stem growth rate, live or dead branch condition, and whether pruning produced smooth or nonsmooth cuts. Distance to occlude is a function of stem size, stub diameter. stem growth rate, live or dead branch condition, and whether pruning produced smooth or nonsmooth cuts. Radius-over-occlusion is a function of stem size, stub length, stub diameter, stem growth rate, and whether pruning produced smooth or nonsmooth cuts. Resume: II doit s'ecouler un certain temps apres que les branches d'un arbre aient ete elaguees pour que chacun des chicots soit recouvert suite a la croissance radiale du tronc. Les forestiers et les amenagistes ont besoin d'avoir une meilleure