Vers une composition optimale de la forêt française : une application de la théorie de la sélection de portefeuille aux critères biotechniques

The objective of this study is to apply the theory of portfolio selection to the diversity of species in the French forests. Financial assets are thereby replaced by tree species. The optimal portfolio is the one that minimizes risk while maintaining the current productivity constant. The study is conducted per department and on 11 species: Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), Maritime pine (Pinus pinaster), European larch (Larix decidua), Douglas fir (Pseudotruga menziesii), Pedunculate oak (Quercus robur), Sessile oak (Quercus petraea), Downy oak (Quercus pubescens), Holm oak (Quercus ilex) and Common beech (Fagus sylvatica). The data comes from databases of the French National Institute of Geographic and Forest Information (IGN). The model outputs are consistent with the current recommendations. At the national level, in the southern part, we observe lower productivity but also better resistance. Conversely, the North, currently more productive, is more subjected to disturbances. The results illustrate the applicability of some economic and financial tools to a forestry setting, for the purpose of decision-making.