Transpiration et photosynthèse du pin maritime : Approches de modélisation du niveau de l'aiguille à l'échelle du couvert

Abstract

This paper summarizes the main steps of a research project aimed at modeling the transpiration, energy balance, water balance and photosynthesis of maritime pine at the needle, tree and canopy levels. Modeling the processes governing the energy and mass fluxes exchanged between forest and atmosphere requires a description of the canopy structure and of the distribution of main canopy characteristics. Canopy structure models vary from the simplest "big-leaf" scheme (canopy is assumed to be homogenous and continuous) to sophisticated 3D models including either a statistical or discrete distribution of canopy elements. For the maritime pine canopy, several approaches have been applied since the beginning of this program with the Hapex-Mobilhy International project in 1986. The results obtained so far are illustrated and the prospects offered by recent projects (European projects "Environment" Euroflux and Lteef-2, Project GIP-Ecofor "Landes 2") are outlined.