Thousands of uprooted storm-felled trees pose deadly risk in Finnish forests

Thousands of unstable tree root balls, some weighing hundreds of kilograms, remain standing in forests across Kokkola after December’s Storm Hannes, posing a lethal hazard as thawing ground causes them to topple unpredictably, Yle reports.

The city of Kokkola estimates there are thousands of such root systems—known as juuripaakku—still upright in municipal forests. While many trunks were cleared after the storm, the heavy root clumps, often weighing up to 300 kg, were left in place due to frozen ground conditions in January.

“They will fall at some point—no one can say when” Ahti Räinä, the city’s forestry engineer, warns that as the soil thaws, even a light gust of wind could suddenly dislodge the root balls. Spruce trees are particularly dangerous, he notes, as their wide, shallow root systems—filled with soil and rocks—can shift without warning.

“Children may see them as exciting play structures, but the risks are severe,” Räinä cautions. “They should be avoided entirely.”

City begins mitigation—but risks remain Kokkola will start addressing the most hazardous stumps near residential areas and high-traffic zones next week using excavators. However, Räinä stresses that not all can be secured, urging forest visitors to stay vigilant.

Beyond root balls, some storm-damaged trees still lean precariously against others and could collapse. “Even if fallen trees have been cleared, risks may linger,” Räinä says. “Keep your eyes open.”

Storm Hannes felled over 5,000 cubic meters of timber in Kokkola alone. Cleanup efforts are expected to continue for at least another year.