Belgium Floods Unleash Century-Old Exotic Plant Life

Following the devastating 2021 floods of the Vesdre river in Wallonia, Belgium, botanists are discovering a surprising resurgence of exotic plant species, seeds carried in wool imported from Australia, South Africa, and South America over a century ago. The region was once a global center for wool processing, and the river’s waters carried seeds from the imported fleece.

These seeds lay dormant for decades, suppressed by invasive species like Japanese knotweed and environmental regulations. The extreme flooding, however, scoured away the knotweed and exposed deep river sediments, allowing the historic seeds to germinate.

Researchers have already identified around 180 non-native plant species. Some, like Medicago peregrina, originally from Iran, are extremely rare and may be extinct in their native habitat.

While some invasive species have been removed, experts believe the climate makes widespread establishment unlikely. The Meise Botanic Garden will publish a comprehensive inventory of the findings later this year.