Effects of rotation, site, and clone on the chemical composition of Populus hybrids

Chemical content values were determined for three Populus clones grown on two dissimilar sites by component (wood, bark, and wood/bark specimens), tissue age (1-, 2- and 4-years-old), and rotation. The chemical content values obtained included extractives, holocellulose, alpha-cellulose, and lignin. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was high in holocellulose and alpha-cellulose content compared to bark, 2) bark was high in lignin and extractive content values compared to wood, and 3) wood/bark chemical content values were between the values for the wood and bark specimens.The chemical content data were analyzed to identify: 1) significant differences between rotations by component (wood, bark, and wood/bark) for a given age, clone, and site, and 2) significant differences between sites for four-year-old wood, bark and wood/bark specimens of a given rotation, and clone. Statistical analyses indicated that significant differences existed among clones, sites, ages, and rotations. Within the wood, bark and wood/bark specimens, tissue age, rotation, and site influenced the chemical content values more than the parentage. Potential chemical yields derived from the three Populus hybrid clones investigated will depend on component, age, rotation, and site with limited parentage effects.