THE TREATMENT OF DECAYED WOOD FROM DEAD TREMBLING ASPEN TREES FOR GROWTH-RING ANALYSIS

This paper elaborates certain procedures briefly outlined in an earlier article. Although dry wood from dead trembling aspen has been found best suited to growth-ring analysis, in its absence use has been made of water-saturated wood from the underside of fallen trunks. A technique of wax impregnation, adaptable to wood in both early and advanced stages of decay, is described. Rapid impregnation with near-boiling wax is sufficient to facilitate transverse sectioning of relatively sound wood; advanced decays require a slower impregnation with cooler paraffin. Hot xylol is used to remove the wax and flatten the section. Successive, overlapped sections provide an extended series of measurements to establish the orientation in time of mortality. Incomplete rings for the years just prior to death are checked by measurement of the outer growth at additional points.