Basalt dust and ‘old forest’ microbes help new trees grow faster

New woodlands can store significantly more carbon if given a boost of crushed rock and soil microbes, according to Imperial College London scientists.

In a four-year trial across 72 plots in Wales, researchers tested two low-tech interventions on newly planted trees.

First, they applied crushed basalt to the soil. The result: up to 27% more carbon stored in the young woodlands.

Second, they added microorganisms from established forests. That led to 13% more aboveground biomass and faster tree growth.

The basalt works through “enhanced rock weathering,” a natural process that pulls CO2 from the atmosphere. The microbes help seedlings absorb nutrients and establish more quickly.“Relatively simple, nature-based interventions can improve tree establishment and increase the carbon uptake of new woodlands during their earliest years,” said lead researcher Dr Bonnie Waring.

The team hopes the methods can be used in future tree-planting schemes to meet climate and biodiversity goals. They stress that further study is needed to see if the early benefits continue as the forests mature.