Phenotypic correlations between juvenile-mature wood density and growth inblack spruce

Phenotypic correlations between juvenile-mature wood density and growth wer e examined based on increment core samples from two plantations, a provenan ce test and a commercial plantation, of black spruce [Picea mariana (Mill.) B.S.P.]. The ring density components are significantly correlated to their respective ring width components: earlywood and ring densities are negativ ely correlated to ring and earlywood widths, respectively, while ring and l atewood densities are positively correlated to latewood width. These hold t rue in both juvenile and mature wood, However, the correlation between ring width and ring density decreases with increasing age. This suggests that t he correlation between wood density and growth rate tends to lessen as the tree ages. For each character, the correlation between juvenile and mature wood is significant but moderate. Thus, juvenile wood characters are only i ndicative of mature wood ones. On the other hand, trees with 12 growth ring s from the pith were good predictors of wood density and radial growth of t he whole tree. Individual growth rings from the juvenile-mature wood transi tion zone can be used to predict to some extent the wood density of either mature wood or the whole tree.