#00040
Prolonged and recurring drought is weakening forests globally, depriving trees of the water they need to grow, defend themselves against pests, and survive heatwaves. It is the foundational stress factor behind most forest dieback crises.
Plant experimental forest "gardens" combining local and non-local tree species and seed provenances to study which ones adapt to future climate conditions. The work is run as a long-term research program by the ONF under the name RENEssences, with plots distributed across French regions including the Grand Est.
Replace single-species, even-aged stands with mixed-species, mixed-age "mosaic" forests so that climate, pest, and drought risk is spread across many trees rather than concentrated on one vulnerable species. The approach is being pushed by the French ONF as the standard response to dieback and is gradually being applied wherever new plantings are made.
Reduce stand density so each remaining tree has access to more soil water during dry periods. This is the most established silvicultural response to drought stress and is widely applied across European temperate forests, including in the Grand Est.
Slow down and infiltrate water at the landscape scale using hedgerows, retention ponds, swales, restored wetlands, and beaver-led re-wetting. The goal is to recharge small aquifers and keep soils moist longer between rainfall events, addressing the structural water shortage that no forestry technique alone can fix.