Variation of Wood Basic Density and Tracheid Length of Different Provenances of Loblolly and Slash Pines

Wood basic density and tracheid length of 22 loblolly pine provenances grown in Guangxi Province and Zhejiang Province and 8 slash pine provenances grown in Guangxi Province introduced from the U. S. and planted in 1984 were determined and analysed. There showed significant variations among different provenances and individual trees within the same provenances. However, the variation among trees was much more significant than that among provenances. Loblolly pine woods from different areas exhibited more significant variation than that from various provenances grown in the same area. The interaction of provenance × environment made significant effects on both basic density and trachcid length of loblolly pine, so did that of provenance × individual tree on basic density of the two pines. Generally no significant correlations were shown between growth rate and wood properties studied here. In the light of the comparison between the materials inrtroduced in 1984 and the references, the loblolly pine and slash pine introduced in earlier time and the local masson pine, it was found possible to obtain new materials of higher wood qualities from the newly introduced pines.