VOLUME INCREMENT IN PINUS-CONTORTA VAR LATIFOLIA - THE INFLUENCE OF STAND DEVELOPMENT AND CROWN DYNAMICS

We examined changes in canopy structure in a Pinus contorta var. latifolia chronosequence to determine if the commonly observed decline in current annual stem increment following canopy closure is associated with declining leaf area efficiency, declining stand-level leaf area, or a combination of both. Leaf area index and stem increment for these P. contorta stands peak at approximately 40-45 years of age. The decline in leaf area index following canopy closure is associated with an increase in crown shyness and a reduction in leaf area efficiency. The characteristic pattern of stand growth, with culmination at about the time of canopy closure, is associated with declines in both the amount and efficiency of leaf area.