Résumé
Capsis (de Coligny et al., 2004 ; http://capsis.free.fr) is an object-oriented software environment designed for hosting a wide range of forest dynamics and stand growth and yield models. It has been designed together by scientists from various French research organizations since 1994. Each model can have its own underlying stand (and if needed tree) description, thus very different kinds of models can be integrated: from stand models to distance-dependent or independent tree models with or without spatialization. Capsis can host heterogeneous models up to the region level and provides libraries to study spatial structures, biomechanics and tree genetics. For a given model and after having loaded a root step from an inventory file or through virtual generation, the user can create different scenarios by alternating growth sequences calculated by the model and silvicultural interventions. The project is organized in three circles: (1) a single developer in charge of designing and maintaining the generic core application, but also dealing with animation, coordination and technical support ; (2) forest growth and dynamics scientists who create the models and implement them into the platform ; (3) end users who use these models for their activities. Every scientist can join the project on condition that he/she accepts the Capsis Charter. Several models have recently been adapted for wood quality issues. PP3 (Meredieu et al., 2005) is a distance-independent tree growth model with a whole-stand growth regulation for pure even-aged stands of Maritime pine (Pinus pinaster) in southwest of France. With a stem taper model, a juvenile wood description coupled with a cross-cutting model, impacts of silvicultural scenarios on grading of logs can be studied. We will consider coupling Capsis and WinEpifn (Meredieu et al., 1999) to improve outputs in near future. Fagacées model simulates the growth of sessile oak (Quercus petraea) and common beech (Fagus sylvatica) for various conditions. A stem taper was developed (Dhôte et al., 2000) and can for example assess the impact of silviculture on ring width all along the stem of the tree. The same work is in progress for beech based on a taper equation from Trincado and Gadow (1996). For Aleppo pine (Pinus halepensis Miller), the main coniferous species in the French Mediterranean region, a tree distance independent growth model is coupled with a branching model allowing for simulation of branch diameter (maximum value and distribution for each branch level) along the crown in relation to silviculture. Further relationships describing crown size and branch length will be implemented in order to contribute to fuelwood simulation on shaded fuel breaks.