Optimisation of forestry trajectories and forest management (OTAF)

Context and challenges

Forests interact with the atmosphere through the biogeochemical cycles of elements and energy exchanges, whether in terms of solar radiation, mass transfer or kinetic energy. Their services, and in particular forest production, are called upon in the transition policies developed, for example, in the framework of intergovernmental agreements.

European forests are subject to multiple management methods, developed from experimental data accumulated over more than a century, essentially oriented towards wood production and based on programmed and precise dynamics of stem density evolution.

Climate change, the instability of environmental policies and the difficult-to-predict evolution of the demand for forest products and services are upsetting this established order. Reconciling the satisfaction of protection, regulation and production services of forests while maximising their climatic resilience is therefore a major scientific and technical challenge, in line with the objectives of the CLIMAE metaprogramme.

Goals

The OTAF project aims to explore, over the period 2020-2100 and for different climate scenarios, the response of stands subjected to a reasoned range of silvicultural itineraries, with a view to identifying viable and adapted trajectories and optimising the services provided by the forest. The diversity of forests, for example in mainland France, makes it necessary to assess these stand dynamic trajectories at the scale of the forest eco-region - or territory -, which integrates stationary variations (soils, climate, species, silvicultural practices, risks) but also at the national and European levels.

OTAF implements:

• A chain of deterministic models adapted to the management of stands on a fine scale (plot) and having already proved its operability at the regional and national levels. Within the framework of the Forests-21 project ("Upstream Forestry" programme, MAA), this chain of models was implemented at the scale of the whole of France to predict the evolution of four major production species subjected to 30 Silvicultural Technical Routes (STR). Within the framework of the BIOSYLVE project ("GRAINE" programme, Ademe), it is being developed to take into account more intensive STR production.
• The development of STRs and silvicultural trajectories adapted to risks, climate change and demand for products and services, and the definition of viable and adapted management and development trajectories including species, STRs and substitutions to be made according to climate change or demand for services.
• Two types of analysis, tested on crops, will be carried out: (i) the distribution of areas between tree species at the regional and national scales, and (ii) the STR adapted for each tree species. In both cases, we will take into account the uncertainty in the future performance of the species x STR combinations, by adapting the methods already used in the agricultural context.

INRAE units involved

• ISPA, Bordeaux
• MIA, Paris
• SILVA, Nancy

External partners : ONF, CNPF, FCBA, ADEME, MAA, IFN-IGN