Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Stem cracks in Norway spruce in southern Scandinavia: causes and consequences. | 315 Ann Sci For 1994 51 315-327 Elsevier INRA Original article Stem cracks in Norway spruce in southern Scandinavia causes and consequences A Persson Swedish University of Agricultural Sciences Department of Forest Yield Research S-77698 Garpenberg Sweden Received 1st September 1992 accepted 17 June 1993 Summary stem cracks in Norway spruce Picea abies L Karst have been recognized as a problem in southern Sweden since 1980. Stands 15-20 years of age that had been planted at a wide spacing on fertile sites were mostly unaffected. Damage was most severe on the larger trees with wide annual rings and a low basic density. Cracking frequency which is partly under genetic control varied between provenances as well as clones. Microscopy revealed that most cracks developed during the period of latewood formation. Hot dry weather which started in July promoted cracking. To prevent cracking it is recommended that suitable provenances be planted on fertile sites at square spacings not more than m. Furthermore clones prone to cracking should be excluded from breeding programmes. stem crack basic density I annual ring I stress-grading Picea abies Resume Les fentes du tronc Chez répicéa commun en Scandinavie méridionale causes et consequences. En Suède méridionale les fentes du tronc d epicea common Picea abies L Karst ont été identifiees pour la premiere fois comme un problème technologique vers 1980. Les peuplements âgés de 15-20 ans plantés à grands espacements sur des sols fertiles ont été les plus abĩmés et c est surtout sur les plus gros arbres présentant des cernes larges et une densité de bois faible que I on a trouvé les plus gros dégâts. La frequence des fentes du troncpeut être contrôlée gốnétiquement au moins en partie. Des variations ont été trouvées entre differentes provenances et clones. Des études au microscope ont montré que la plupart des fentes sont apparues pendant la saison de formation de bois final. Une période de temps chaud et sec au mois de juillet
