Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Modelling canopy growth and steady-state leaf area index in an aspen stand. | 611 Ann. For. Sci. 57 2000 611-621 INRA EDP Sciences Original article Modelling canopy growth and steady-state leaf area index in an aspen stand Olevi Kull and Ingmar Tulva a Institute of Ecology Riia 181 51014 Tartu Estonia b Institute of Botany and Ecology Tartu University Lai 40 Tartu Estonia Received 1 February 1999 accepted 26 October 1999 Abstract - We developed a canopy growth model to analyse the importance of different structural properties in the formation of equilibrium leaf area index in a Populus tremula canopy. The canopy was divided into vertical layers with the growth and structural parameters of each layer dependent on light conditions. Horizontal heterogeneity was considered through clumping parameter. The principle growth parameters considered were long shoot bifurcation ratio number of short shoots produced by one-year-old long shoot short shoot survival and number of leaves per shoot. Parameter values and relationships are based on field measurements of an aspen stand in Jarvselja Estonia. Depending on initial conditions leaf area index reaches the steady state in 5-20 years. The value of initial density of long shoots affects the time needed to achieve equilibrium but has little influence on final LAI value. The most influential parameters in predicting the final LAI are thus of the relationship between long shoot bifurcation ratio and light. canopy growth model Populus tremula leaf area index shoot bifurcation Résumé - Modélisation de la croissance et de l indice de surface foliaire LAI dans un peuplement de tremble. Nous avons développé un modèle de croissance de la canopée pour analyser l importance de differentes propriétés structurelles dans la formation de l indice foliaire LAI dans une canopée de Populus tremula. La canopée a été divisée en couches verticales dans lesquelles la crois-sance et les paramètres structuraux de chaque couche dépendent des conditions lumineuses. L hétérogénéité horizontale a été prise en compte au travers de .
