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Báo cáo lâm nghiệp: "Frost damage on the terminal shoot as a risk factor of fork incidence on common beech (Fagus sylvatica L.)"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Frost damage on the terminal shoot as a risk factor of fork incidence on common beech (Fagus sylvatica L.). | Ann. For. Sci. 64 2007 79-86 79 INRA EDP Sciences 2007 DOI 10.1051 forest 2006091 Original article Frost damage on the terminal shoot as a risk factor of fork incidence on common beech Fagus sylvatica L. Francois NlNGRE Francis Colin INRA Unité Mixte de Recherches INRA-ENGREF Laboratoire d etudes des ressources Forêt-Bois Équipe Croissance et Production Nancy France Received 27 September 2005 accepted 16 March 2006 Abstract - Forking is a frequent flaw in beech which can adversely affect the formation of high quality logs. Even though the hypothesis that late frosts increase forking is widely accepted by forest managers it remains to be proved and quantified experimentally. Damage caused by a late frost on 15 May 1995 to young beech trees in an experimental site at Lyons-La-Forêt France and the consequences on the development of forking were analysed. The beech trees were 17 years old with heights between 1.5 and 9 m. Of all the plantation densities tested only the lowest density 625 ha showed various and severe frost damage. Three levels of immediate damage to the growing terminal shoot were observed with increasing intensity from 1 no trace of frost damage 2 reddened leaves and 3 frost-nipped shoots. The intensity of visible damage to the terminal shoot appeared to be very dependent on the height of the plant which justified our original experimental approach based on an evaluation of the damage for each individual. Almost all of the beech trees less than 4 m high suffered frost damage and all those taller than 7 m were unaffected. Three-year-old forks due to frost which occured in May 1995 were recorded at the end of 1997 using an objective definition based on dendrometric and age criteria. The worst frost damage resulted in a significant increase in the risk of fork emergence 71.7 of the plants were forked . With a risk related to forking in the presence of frost-nipped shoots equal to 2.15 and a fraction of the attributed risk of 0.36 it was concluded that the