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Báo cáo khoa học: "A flexible radial increment taper equation derived from a process-based carbon partitioning model"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: A flexible radial increment taper equation derived from a process-based carbon partitioning model. | Ann. For. Sci. 59 2002 141-154 INRA EDP Sciences 2002 DOI 10.1051 forest 2002001 141 Original article A flexible radial increment taper equation derived from a process-based carbon partitioning model Christine Deleuzea and Franẹois Houllierb aÉquipe ENGREF INRA Dynamique des Systèmes Forestiers ENGREF 14 rue Girardet 54042 Nancy Cedex France b UMR CIRAD-CNRS-INRA-Université Montpellier II Botanique et Bioinformatique de 1 Architecture des Plantes AMAP CIRAD TA40 PS2 Boulevard de la Lironde 34398 Montpellier Cedex 5 France Received 29 November 2000 accepted 8 March 2001 Abstract - Carbon allocation to the cambium along the stem is represented by a reaction-diffusion model along a continuous sink. Vertical variations of stem area increment along the stem are then theoretically connected to partitioning coefficients between tree compartments at different spatial scales. This model is very sensitive to environmental growth conditions and demonstrates the importance of topology and geometry in models of secondary tree growth. An analytical resolution is proposed to describe the vertical profile of stem area increment between crown basis and soil level. An empirical parametric equation is derived from this theoretical model. The 3 parameters of this equation are related to the internal and environmental conditions of the tree. These parameters can be used as indicators in order to study the variability of stem taper. This equation is separately fitted on data from two experiments with different silviculture and site quality for Picea abies of different ages. Variation in the parameters is discussed according to growth conditions. This equation is further integrated in order to predict stem volume increment. Finally some simple characteristic heights are derived from this function as indicators of functional crown basis. These heights are systematically calculated to predict crown recession. They are finally compared to heights measured during field work. allocation .