tailieunhanh - Báo cáo lâm nghiệp: ": Climate-tree-growth relationships of Quercus petraea Mill. stand in the Forest of Bercé (“Futaie des Clos”, Sarthe, France)"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Climate-tree-growth relationships of Quercus petraea Mill. stand in the Forest of Bercé (“Futaie des Clos”, Sarthe, France). | Ann. For. Sci. 61 2004 361-372 INRA EDP Sciences 2004 DOI forest 2004029 361 Original article Climate-tree-growth relationships of Quercus petraea Mill. stand in the Forest of Bercé Futaie des Clos Sarthe France Francois LEBOURGEOiSa Guillaume C0USSEAUb Yves Ducosb a Unité Mixte de Recherche INRA-ENGREF 1092 Laboratoire d Etude des Ressources Forêt-Bois Équipe Écosystèmes Forestiers et Dynamique du Paysage ENGREF 54042 Nancy Cedex France b Office National des Forêts Service départemental du Loiret 45 France Received 25 March 2003 accepted 20 August 2003 Abstract - The past history of a 300-year-old Quercus petraea stand the Futaie des Clos 8 ha located 20 km from the town of Le Mans in the Forest of Bercé in the western part of France Sarthe was analysed by a dendroecological approach. According to the number of healthy trees alive 400 the stand age 300 years and the dimensions of the trees dia 92 cm height m this plot constitutes one of the most remarkable oak grove in France. High competition pressure between trees appeared to be the most important factor to explain the high-quality timber high straight stems without wood defaults narrow regular rings . After an initial 90-year period of decrease this stand shows a 1 mm-year-1 growth increment from the 1810s to the present. The growth increase of 40-50 occurring for over than 20 years can be interpreted as a response to the increase of harvesting intensity. The influence of climate was evaluated by comparing earlywood latewood and total ring indices with monthly climatic data collected at Le Mans over the period 1921-2001. Extreme growth years coincided with wet or dry springs May-June 40 of rainfall in relation to normal conditions often associated with warm or fresh July. The climatic models accounted for between 18 and 26 of the variability of ring widths and suggested that earlywood formation depended mainly on previous autumn hydric balance and winter temperature whereas the growth of the .