Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Modelling of the shape of red heartwood in beech trees (Fagus sylvatica L.) based on external tree characteristics. | Ann. For. Sci. 63 2006 905-913 INRA EDP Sciences 2006 DOI forest 2006074 905 Original article Modelling of the shape of red heartwood in beech trees Fagus sylvatica L. based on external tree characteristics Holger WERNSDORFERa b Gilles Le MoguéDECa Thiéry Constant Frédéric MOTHEa Gérard NEPVEUa Ute SEELlNGb a LERFoB UMR INRA-ENGREF 1092 Wood Quality Research Team INRA Nancy Research Centre 54280 Champenoux France b University of Freiburg Institute of Forest Utilization and Work Science Werderring 6 79085 Freiburg Germany Received 01 June 2005 accepted 13 January 2006 Abstract - The shape of red heartwood in beech was studied on 16 trees based on the mean red heart radius at about every 2 m along the stem axis up to the crown base. The longitudinal red heart shape was modelled by sections of bell-shaped curves given by an exponential function with a fourth order polynomial term. Using individual tree parameters for the red heart width length and height the observed red heart shapes were closely described by the model. An approach of a predictive model at the standing tree level was developed for estimating these parameters from the diameter at breast height height of the crown base related to total tree height and height of a possible red heart initiation point. Remaining issues concerning the model structure should be analysed on a higher number of samples. An application of the model at the log level could be developed. red heart model beech Fagus sylvatica shape Résumé - Modélisation de la forme du cffiur rouge du hêtre Fagus sylvatica L. à partir de caractéristiques externes de l arbre. La forme du creur rouge du hêtre a été décrite sur 16 arbres par des mesures du rayon moyen du creur rouge effectuées tous les 2 m de hauteur environ jusqu a la base du houppier. La forme longitudinale du creur rouge a été modélisée par des sections de courbe en cloche données par une fonction exponentielle avec un terme polynomial d ordre quatre. Le modèle comprenant des
