tailieunhanh - Báo cáo khoa học: "Carbon-based models of individual tree growth: A critical appraisal"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Carbon-based models of individual tree growth: A critical appraisal. | Ann. For. Sci. 58 2001 469-506 INRA EDP Sciences 2001 469 Review Carbon-based models of individual tree growth A critical appraisal Xavier Le Rouxa André Lacointea Abraham Escobar-Gutiérrezb c and Séverine Le Dizèsa a . PIAF INRA-Université Blaise Pascal Site de Crouel 234 av. du Brezet 63039 Clermont-Ferrand Cedex 02 France b Forestry Commission Northern Research Station Roslin Edinburgh Midlothian EH25 9SY UK c Present address Horticulture Research International Wellesbourne Warwick CV35 9EF UK Received 7 September 2000 accepted 1st February 2001 Abstract - Twenty-seven individual tree growth models are reviewed. The models take into account the same main physiological processes involved in carbon metabolism photosynthate production respiration reserve dynamics allocation of assimilates and growth and share common rationales that are discussed. It is shown that the spatial resolution and representation of tree architecture used mainly depend on model objectives. Beyond common rationales the models reviewed exhibit very different treatments of each process involved in carbon metabolism. The treatments of all these processes are presented and discussed in terms of formulation simplicity ability to account for response to environment and explanatory or predictive capacities. Representation of photosynthetic carbon gain ranges from merely empirical relationships that provide annual photosynthate production to mechanistic models of instantaneous leaf photosynthesis that explicitly account for the effects of the major environmental variables. Respiration is often described empirically as the sum of two functional components maintenance and growth . Maintenance demand is described by using temperature-dependent coefficients while growth efficiency is described by using temperature-independent conversion coefficients. Carbohydrate reserve pools are generally represented as black boxes and their dynamics is rarely addressed. Storage and reserve mobilisation are often