Overview
- The Laboratoire des sciences du climat et de l’environnement published a national study on July 9 that analysed more than 500,000 trees from the Inventaire forestier national and found natural mortality rose 1.5 to 4 times for common species between 2015 and 2023.
- Researchers tied the increase to accumulating seasonal climate anomalies, explaining that very wet springs followed by dry summers and unusually warm winters raise stress on trees and help pests survive.
- Nearly half of the 52 species studied show significant mortality increases, with common beech deaths more than doubling since 2019 and chestnut mortality exceeding 2.5 percent, concentrated in the Jura, Vosges and Grand Est regions.
- The Observatoire national des forêts reported on July 1 that annual tree mortality climbed 125 percent over ten years and that 92 percent of forests are affected by drought, a situation worsened by intense 2026 heatwaves and recent wildfires.
- A cross-party group of about fifty deputies has proposed a law to overhaul silviculture and strengthen the Office national des forêts, a move prompted by scientists’ warnings that rising tree deaths threaten biodiversity, carbon storage and increase fire risk for communities and firefighters.