DEPENDENCE OF VOLUME INCREMENT OF INDIVIDUAL TREES ON DOMINANCE, CROWN DIMENSIONS, AND COMPETITION

A study of the volume increment of individual trees over one growing season in a 23-year-old stand of Sitka spruce (Picea sitchensis Carr.), indicated that narrow crowned trees were more efficient producers of increment. Other factors being constant, trees of greater girth at breast height were found to be inherently better producers. Trees of the upper canopy were generally more efficient than those of the lower canopy under varying conditions of competition. Shorter periods of growth were recorded in lower canopy trees and with trees under conditions of greater competition. © 1969 Oxford University Press.