The Variations in Tracheid Length of Pseudotsuga menziesii (Mirb.) Franco Wood in Relation to Cambium Age, Site, and Growth

This study investigated the variations in tracheid length of Pseudotsuga menziesii (Mirb.) Franco from three sites in Croatia in relation to cambium age, within- and between-site differences, and growth rate. Tracheids are the main structural element in P. menziesii wood, varying in length following different patterns that should be precisely determined. After the maceration procedure, earlywood tracheid length (EWTL), latewood tracheid length (LWTL), annual growth ring tracheid length (RTL), earlywood ring width (EWW), latewood ring width (LWW), and annual ring width (ARW) were measured in selected annual growth rings. The significant effect of annual growth rings and zone interaction for EWTL and LWTL, as well as of annual growth rings, trees, and sites for RTL, was determined. The results conclude on the differences between the trends in EWTL and LWTL from pith toward the bark. In addition, the correlation analysis between the tracheid length and different growth patterns was investigated, and very weak or no association between the variables was detected. This research contributes to better understanding the degree of wood uniformity of P. menziesii from the technological perspective, as well as the variability factor in the optimization of forest management with favoring overall wood quality.