tailieunhanh - Báo cáo lâm nghiệp: "A method for describing and modelling of within-ring wood density distribution in clones of three coniferous species"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài:"A method for describing and modelling of within-ring wood density distribution in clones of three coniferous species" | Ann. For. Sci. 61 2004 759-769 INRA EDP Sciences 2005 DOI forest 2004072 759 Original article A method for describing and modelling of within-ring wood density distribution in clones of three coniferous species Milos IVKOVICÍa b Philippe ROZENBERGa a INRA Centre de Recherches d Orléans Unité d Amélioration Génétique et Physiologie Forestières France b Current address ENSIS Tree Improvement and Germplasm CSIRO Forestry and Forest Products PO Box E4008 Kingston ACT 2604 Australia Received 5 January 2004 accepted 15 September 2004 Abstract - Wood density within growth rings was examined and modelled for clones of three coniferous species Norway spruce Douglas fir and maritime pine. Within-ring density measurements obtained by X-ray scanning were represented as a frequency distribution. The distribution was described using both moment-based and non-parametric robust statistics and its sample quantiles were modelled using the generalised lambda distribution. In Norway spruce the frequency distribution of wood density was unimodal and asymmetric . positively skewed whereas in Douglas fir and maritime pine the distribution was bimodal . mixture of two skewed distributions corresponding to earlywood and latewood ring zones . In all three species analyses of covariance revealed that after adjustment for ring width or mean ring density there was still significant p clone variability in within-ring frequency distribution parameters . clones with similar growth rate or mean density had different within-ring structure . Norway spruce Douglas-fir maritime pine wood density modelling Résumé - Une méthode pour description et modélisation de la distribution de densité intra-cerne du bois parmi les clones de trois espèces de coniferes. La densité du bois dans les cernes de croissance a été examinée et modélisée pour les clones de trois espèces de coniferes épicéa commun sapin Douglas et pin maritime. Les mesures de densité intra-cerne obtenues par densitométrie