Context

Mountain forests provide many services, divided into four categories by the Millennium Ecosystem Assessment (2005) : supply, regulation, cultural services, and self-maintenance.
In the future, climate change will lead to an increase in high-altitude species that could result in a decline of resinous and subalpine species. Winters will be milder but late frosts will have a greater impact. Moreover, the increasing summer temperatures combined with a decrease in summer rainfall will aggravate the water scarcity. These changes in species composition and new climate conditions could adversely affect biodiversity and timber production (Benoît Courbaud et al., 2010 [1]) by compromising the regeneration capacity and by causing forest dieback .
From a forest management perspective, one of the solutions is to identify which species is at risk within their ecological niche, and to replace them gradually by more resilient species.

The initiative

The main objective of this project, led by the Réseau d’avenir pour la foret Iséroise, is to make forest more resilient to climate change, thanks to natural regeneration.
This includes the removal of ancient coniferous trees and the implementation of four fir trees species: pectin fir, Nordmann fir, Bornmuller fir and Cephalonia fir. Varieties and their provenance have been chosen to reflect the genetic diversity of the species, which is the main source for adaptation to climatic conditions (such as increasing drought tolerance).
The comparison of these different fir trees in a forest environment and their classification according to various factors (such as growth, resistance to water stress…) will help address climate change and especially dieback of local fir trees.

Results, limits and enable factors

A preparatory work was first carried out, with the removal of coniferous, considered as having no future. A hundred seedlings were then gradually implemented since autumn 2020.
In the long term, the aim of this forest is produce timber, capture more CO2 and produce seeds of more vigorous trees for natural regeneration.
This project is a pioneering approach in the Alps. An extension of this initiative on the Pierre Chatel site is expected in the coming years, with other provenances or species from the Mediterranean basin.