Crushed rock helps new forests grow faster and store 27% more carbon, study finds

Wales: A sprinkle of crushed basalt rock is helping young forests grow quicker and lock away more carbon, according to a new study by Imperial College London.

The research, part of the Glandwr Forest Carbon Study in Wales, tracked 26,000 trees across 72 plots. Plots treated with basalt dust showed a 27% increase in aboveground carbon storage in soil and tree roots.

The idea, called “enhanced weathering,” works as the rock breaks down and releases minerals that improve soil nutrients.

Adding soil microbes from old forests showed some benefit for oak and spruce, but overall results were not significant. Combining both methods also had no clear effect yet.

“Simple, nature-based interventions can improve tree establishment and increase carbon uptake in new woodlands,” said study author Dr. Bonnie Waring.

Scientists say longer monitoring is needed, but early results suggest crushed rock could be a low-cost tool to help mass tree-planting projects succeed.