TAILIEUCHUNG - Báo cáo khoa học: "Hardness and basic density variation in the juvenile wood of maritime pine"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Hardness and basic density variation in the juvenile wood of maritime pine. | Ann. Sci. For. 55 1998 911-923 Inra Elsevier Paris 911 Original article Hardness and basic density variation in the juvenile wood of maritime pine Jean-Franẹois Dumail Patrick Castéra Pierre Morlier Laboratoire de rhéologie du Bois de Bordeaux CNRS Inra Université Bordeaux I Domaine de I Hermitage BP 10 33610 Cestas Gazinet France Received 15 May 1997 accepted 6 July 1998 Abstract - This paper investigates the within- and between-tree variability of hardness and basic density in two stands of 11-year-old and 20-year-old maritime pine trees grown in the south-west of France. A slight increase was found in the inner core hardness of the 11-year-old trees and in basic density of the 20-year-old pines with decreasing tree height. Between the 1st and 13th annual rings of the 20-year-old trees hardness increased by and basic density by on average. These variations were strongly tree-dependent. A significant correlation was found between hardness and basic density even when each sampling position was considered independently. Inra Elsevier Paris. variability juvenile wood hardness basic density maritime pine Resume - Variations de densité et de dureté dans le bois juvenile de pin maritime Pinus pinaster . Cet article traite de la variabilité intra- et inter-arbres de la dureté et de I infradensite. L echan-tillon étudié est compose de 17 pins maritimes de 11 ans et de 20 pins maritimes de 20 ans. Ces arbres sont issus de deux parcelles situées sur le site du Centre de recherches forestieres de LTnra de Pierroton en France. Pour les pins de 11 ans une légère augmentation de la dureté 13 9 a été mise en evidence lorsque la hauteur dans 1 arbre diminue. L infradensite augmente également 6 5 dans les mêmes conditions sur les arbres de 20 ans. Les variations du coeur vers 1 écorce sont res-pectivement de 49 8 pour la dureté et de 18 7 pour I infradensite pour les arbres de 20 ans. Ces gradients ont été mesurés entre le premier et le treizieme cerne et sont .

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