tailieunhanh - Báo cáo khoa học: "Effect of drying treatments on warping of 36-year-old white spruce seed sources tested in a provenance trial"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Effect of drying treatments on warping of 36-year-old white spruce seed sources tested in a provenance trial. | Ann. For. Sci. 59 2002 503-509 INRA EDP Sciences 2002 DOI forest 2002034 503 Original article Effect of drying treatments on warping of 36-year-old white spruce seed sources tested in a provenance trial Jean Beaulieua Bruno Girarda b and Yves Fortinb Natural Resources Canada Canadian Forest Service Laurentian Forestry Centre 1055 du PEPS . Box 3800 Sainte-Foy Quebec G1V 4C7 Canada bFaculté de foresterie et géomatique Université Laval Sainte-Foy Québec G1K 7P4 Canada Received 5 July 2001 accepted 31 January 2002 Abstract - Wood from plantations will increasingly become a major source of supply for the lumber industry and this raw material is likely to have characteristics much different from those of the wood harvested in natural forests. This could require costly adjustments to manufacturing processes to maintain the quality of the end-use products. In Canada white spruce Picea glauca Moench Voss is one of the main reforestation species and one of the most extensively used for lumber. In this study we investigated the genetic variation in warping in kiln drying of 25 white spruce provenances grown in a plantation and one from a second-growth forest stand. All of them were from the Great Lakes - St. Lawrence region. Two drying treatments were applied . conventional and high-temperature drying. For bow crook and twist warp defects after drying significant differences were not found among the provenances tested nor between the drying treatments. However significant differences were revealed between the mean of all provenances plantation-grown and wood from second-growth forests for crook and twist defects. The high proportion of tree to tree variation provides grounds for hope of rapid gains through mass selection. kiln drying bow crook twist plantation Résumé - Effets du procédé de séchage sur le gauchissement du bois d epinette blanche issu d une plantation de 36 ans. Le bois produit et récolté dans des plantations est appelé à devenir une source d .