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Báo cáo khoa học: " The wood density of 3 Eucalyptus saligna Smith clones in relation to age"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: " The wood density of 3 Eucalyptus saligna Smith clones in relation to age. | 347 Ann Sci For 1995 52 347-352 Elsevier INRA Original article The wood density of 3 Eucalyptus saligna Smith clones in relation to age JT Lima Departamento de ciências florestais Escola superior de agriculture de Lavras 37200-000 Lavras-MG Brazil Received 30 November 1992 accepted 19 December 1994 Summary The evaluation of the basic density of wood of Eucalyptus spp cultivated extensively in Brazil has become of fundamental importance in various types of projects due to the fact that density is the principal index of wood quality. Through periodic collections of wood samples from 3 clones of E saligna between the ages of 9 and 42 months the interclonal and intraclonal variations at various ages as well as temporal behaviour were determined. The analysis of the results led to the following conclusions I the mean basic density of the wood of the 3 clones all together can be estimated in function of age by the cubic model BD -0.018510 0.53200.A - 0.001920 A2 0.000023 A3 R2 0.832 and F 260.89 ii at the level of the clone the basic density for each individual can be calculated by the following equations BDi 0.015179 0.052466 A-0.001966 A2 0.000024 A3 BD2 -0 070743 0.057755 A-0.002030 A2 0.000024 A3 and BD3 0.000867 0.049257 A -0.001767 A2 0.000021 A3 and ill the intraclonal variation in relation to basic density is relatively low at the ages studied. wood density I clone I Eucalyptus saligna Resume Evolution de la densité du bois selon I age de 3 clones ứ Eucalyptus saligna Smith. Étant donné importance économique ỞEucalyptus spp dans la production ỉorestière brésilienne ce bois est de plus en plus étudié vis-à-vis de 1 amélioration de sa qualité. On connatt le role important joue par la densité sur la qualité du bois. C est pourquoi on a évalué 1 évolution de I infradensite DB du bois de 3 clones dE saligna entre 9 et 42 mois. Les evaluations ont porté sur les variations inter et intra-clonales pendant cede période. Les analyses effectuees conduisent aux résultats .