WOOD DENSITY AND EXTRACTIVE CONTENT VARIATION AMONG JAPANESE LARCH (LARIX KAEMPFERI [LAMB.] CARR.) PROGENIES/PROVENANCES TRIALS IN EASTERN CANADA

摘要

Twelve-yr-old Japanese larch (Larix kaempferi [Lamb.] Carr.) stems of 20 different progenies and/or provenances were obtained. Two disks of 5 cm thickness were cut at approximately 0.25 and 2.7 m from the ground. Two wedges were cut from each disk to determine basic density at these two heights. The remaining log was used to obtain standard samples for the determination of basic and oven-dry densities closest to the bark. The adjacent material of standard samples was used to produce sawdust for the determination of hot-water extractive content. Basic and oven-dry densities were then corrected by the mass of extractives. Wedge basic density showed a significant variation along the stem. Density was higher at 0.4 m than at 2.75 m in height. However, no significant effect of progeny/provenance was found, nor for basic and oven-dry densities. Once these densities were corrected, the progeny/provenance showed a significant effect, which allowed a progeny grouping by density. Hot-water extractive content was also significantly affected by the progeny/provenance and it varied between 2.9% and 6.9%. Progeny 7280 would have an interesting potential among progeny/provenance for lumber and pulping uses as it showed the lowest water-soluble extractive content, the highest corrected densities, and high growth rate. In general, corrected densities and extractive content would be more appropriate for a preliminary selection of the progenies/provenances according to the final utilization. Further studies of other wood properties would be necessary to confirm these results.