Coping with extreme weather events across space and time: a case study from the French forest sector under windstorm[Faire face aux phénomènes météorologiques extrêmes à travers l'espace et le temps : l'étude de cas du secteur forestier français face aux tempêtes]

Extreme weather events increasingly challenge forest ecosystems, requiring effective post-crisis interventions. Coping strategies for supply shocks in the forest sector typically rely either on temporal adjustments, such as storage to smooth supply disruptions, or on spatial reallocations, such as transport subsidies to redistribute supply. This study compares these two approaches by simulating crisis wood storage and transport subsidies following a large-scale windstorm affecting French forests. Using the French Forest Sector Model (FFSM), a bioeconomic partial equilibrium framework, we simulate sectoral and carbon sink responses across spatial and temporal scales, and develop a social welfare indicator integrating producer and consumer surplus, policy costs, and carbon externalities. Results reveal trade-offs. Storage stabilizes prices and keeps them higher, at the expense of producer and consumer surplus, but increases overall social welfare through better preservation of the forest carbon sink and greater spatial equity: it reduces transfers toward less affected regions and benefits more severely windstorm-impacted regions. Transport subsidies increase wood mobilization as well as producer and consumer surplus, but perform worse in terms of social welfare gains, and tend to favor regions spared by the windstorm at the expense of those that would need support the most. These contrasting regional patterns highlight how each policy redistributes the burden of the shock across territories, with storage promoting convergence and transport subsidies reinforcing pre-existing disparities. Trade-offs thus arise between market performance and carbon sink preservation, between spatial scales of intervention, and between short- and long-term temporal considerations, offering policy-relevant insights for future forest crisis management.