Test new species and provenances

No one knows for certain which tree species will still thrive in continental Europe by 2080. The species that dominated for centuries — beech, spruce, fir, ash — are visibly failing in many places, but the alternatives are far from obvious. Some candidates are local species from drier microclimates; others are species or provenances from southern Europe, the Balkans, or even further afield. Each comes with unknowns about pests, soils, frost tolerance, and biodiversity impact. The ONF's RENEssences project addresses this through experimental "gardens": small, dense plots in which dozens of species and provenances are planted side by side, then monitored for decades. The data feeds into national replanting recommendations as it accumulates. Plots have been established across the country, and the network is growing. The strength of the approach is that it is empirical rather than guess-based. The weakness is time. Species selection decisions need to be informed by results that will not be available for 20 to 40 years — and many forests cannot wait that long. RENEssences is still the most rigorous source of guidance available, but the gap between when we need answers and when we will have them is the central tension of forest climate adaptation.