Scientists in South Africa have discovered the oldest termite mounds in the world, which have stored carbon for thousands of years.
Using radiocarbon dating methods, the research team found termite mounds along the branches of the Buffels River in Namaqualand—a region on the west coast of South Africa where approximately 20% of the landscape is covered by such mounds. These are the oldest termite mounds ever known, with some being up to 34,000 years old.
Purple flowers growing on ancient termite mounds in Namaqualand, South Africa – (Photo: Jannick Niewoudt and Alastair Potts).
According to Michele Francis, the lead author of the study and a researcher at Stellenbosch University in South Africa, the termites daily forage for wood scraps to bring back to their nests. Over the years, these organic materials accumulate and form a rich carbon reservoir.
In previous research, Francis’s team estimated that each termite mound could store around 14 tons of carbon. Therefore, she was eager to understand how groundwater, air, and soil interact within these mounds to “lock” away such a significant amount of carbon.
This time, the team conducted chemical analyses on the termite mounds and observed the chemical processes that transfer carbon from the atmosphere into the mounds. They found that the termites’ collection of wood debris makes the soil more porous and water-absorbent. Subsequently, bacteria in the soil convert this stored carbon into calcium carbonate.
During heavy rainfall, the calcium carbonate in the termite mounds chemically reacts with carbonic acid, forming carbon dioxide (CO2) that dissolves into the rainwater. This increases the potential for CO2 sequestration in the atmosphere.
A termite mound in Namibia – (Photo: SciTechDaily).
This process locks away new carbon at a depth of about 1 meter below the surface of the termite mounds for long-term storage, according to LiveScience on June 26.
“By studying these termite mounds, scientists can gain better insights into combating climate change, using nature’s own processes to sequester carbon. These mounds not only illuminate the past but also provide important clues for our future,” said Francis.
