Raw Material Quality of Short-Rotation, Intensively Cultured Populus Clones. I. A Comparison of Stem and Branch Properties at Three Spacings

Raw material properties(specific gravity, cell lengths, cell type percentages, and bark percentages) were examined in trees from nine Populus hybrid clones growing under short-rotation, intensive culture (SRIC) for 4 years.Statistical analyses were conducted to determine clonal, spacing, branch, and stern effects on wood and bark properties.The analysis indicated significant clonal and parental effects on some of the properties.Aigeiros-Tacamahaca hybrids generally had higher specific gravity (SG) than those composed of only Aigeiros parentage.Branch properties influenced this difference.Within the Aigeiros-Tacamahaca clones, the P. candicans x P. berolinensis hybrids had shorter fibre lengths and lower stern wood SG.No spacing effects were observed.Significant differences were found between stern sampIes and branch sampIes -the stern wood sampIes had longer cells and less bark.The variation in raw material properties observed in this study indicate that these properties have potential for improving poplar clones for SRIC.