Trees across Belgium and Germany are shedding their leaves weeks ahead of schedule as a persistent drought grips western Europe, with four out of five trees in Germany now classified as diseased according to the country's 2025 forest health report.
Multiple German states recorded heat records in July, and major rivers including the Rhine, Elbe and Danube have fallen to extreme lows. In North Rhine-Westphalia, 94 percent of land area was affected by unusual drought by late July. The city of Wuppertal alone felled nearly 1,000 dead urban trees in 2026, while researchers at the Technical University of Munich found an unprecedented loss of biomass across European forests since 2018.
At Ghent University's experimental forest of beech and oak, ecophysiologist Kathy Steppe notes that birch trees are the most drought-sensitive species, followed by beech, plane and oak. Trees can partially repair drought-induced embolisms overnight, but prolonged dry spells overwhelm that recovery mechanism.