tailieunhanh - Báo cáo khoa học: "Litter production in an Atlantic beech (Fagus sylvatica L.) time sequence"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Litter production in an Atlantic beech (Fagus sylvatica L.) time sequence. | Ann. For. Sci. 58 2001 755-768 INRA EDP Sciences 2001 755 Original article Litter production in an Atlantic beech Fagus sylvatica L. time sequence Myriam Lebreta Claude Nysb and Franẹoise Forgearda aLaboratoire d Ecologie Végétale UMR 6553 Complexe Scientifique de Beaulieu Université de Rennes 1 35042 Rennes Cedex France bEquipe Cycle Biogéochimique Inra - Centre de Nancy 54280 Champenoux France Received 19 January 2001 accepted 3 May 2001 Abstract - Litterfall is the first phase of the biogeochemical cycle and returns nutrients to the soil. This paper demonstrates the quantitative distribution of the different components throughout the year in four stands of a beech time sequence. Litterfall increases as the forest evolves and as basal area increases t ha an in the thicket t ha an in the mature high forest. Leaves represent 90 of the total litterfall in the young stand and 70 in the oldest stand. The proportion of leaves decreases during forest rotation. Most of the categories are related to the age and basal area because of the architecture and maturity of the trees. Other factors could explain litterfall dynamics . human management or animals. Climate is a preponderant factor for the litterfall production and plays a role in the species phenology. The litterfall dynamics during the time sequence and the observed shifts in phenology give rise to different pedogenetic processes. litter production beech time sequence dry matter Résumé - Production de litière dans une chronoséquence d une hêtraie Fagus sylvatica atlantique. Les retombées de litière sont à la base des cycles biogéochimiques et assurent le retour au sol des nutriments. Cet article présente la repartition quantitative par compar-timent au cours de deux ans de suivi et dans quatre peuplements de hêtre d une chronoséquence. Les retombées totales de litière augmentent avec l âge de la parcelle et la surface terrière de 2 1 t ha an dans le fourré à 4 7 t ha an dans la vieille futaie. Les .