Modeling oak and beech regeneration in mixed and uneven-aged forests : a process-based approach for changing environments

Details

Supervisors

Jonard, Mathieu

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en sciences et technologies de l'environnement

Abstract

Climate change and human impacts on the forest ecosystems forced to review forest management practices. The forests need to be more resilient to face these disturbances. The solution found for this is mixed and uneven-aged forests which bring a lot of positive externalities in addition to the increased resilience. But the complexity of the forest systems is therefore increased. Process-based and spatially explicit models can bring the tools to integrate this complexity and predict the behavior of the ecosystem along with the changes associated with climate change. This is the aim of Heterofor, a process-based model. But the uneven-aged stands need to take regeneration into account to make long-term predictions. This Master’s thesis focus on the development of the regeneration module in Heterofor. The seedling morphology, growing process, and mortality process are described for oak and beech. The module uses the radiation to calculate a height increment. The seedling characteristics are derived from the height or the diameter. With these, photosynthesis is computed thanks to Castanea library. And a mortality rate is calculated using a resource sharing method between the size class net primary production and the individual growth needs. The validation of the module is carried by reproducing the self-thinning lines with different scenarios. The self-hinning lines were well reproduced in full light conditions. Other simulations were carried to analyze the behavior of seedlings in mixed regeneration, under a canopy, and with water stress.