

An aerial view of the termite mounds in Namaqualand, South Africa, coated by spring flowers. The flowers develop preferentially on the mounds as a result of they’re richer in vitamins than the encircling soil.Credit score: Alastair Potts
The world’s oldest inhabited termite mounds, found in Namaqualand, South Africa, are offering perception into the position of those tiny engineers in pure carbon sequestration.
A research on the 34,000 year-old mounds, printed in Science of Complete Atmosphere, was led by scientists from the Division of Soil Science and the Division of Earth Sciences at Stellenbosch College (SU) in South Africa, together with the Institute for Nuclear Analysis in Hungary.
The mounds’ prime 20cm of shallow topsoil accumulates carbon-rich natural matter, which is then simply misplaced to the ambiance. Microbes additionally take within the natural carbon and respire it as carbon dioxide. However on the depth to which the termites convey the natural materials, 0.6 to 1.9m underground, the carbon is much less more likely to enter the ambiance whereas decomposing.
Lead writer, Michele Francis, says age in all probability performs a job, and the bigger, older mounds may accumulate extra carbon.
The authors discovered that by periodically refreshing youthful natural matter deep underground, the southern harvester termite, Microhodotermes viator, performs a extra vital position in storing carbon than beforehand thought.
Standing in entrance of an historical termite mound are Andrew Watson, Marli Kleyn), Dr Jani van Gend and Michele Francis, lead writer on the research, and Senior Lecturer (Extraordinary) within the Division of Soil Science at SU.Credit score: Stellenbosch College
“Termites collect grass and woody vegetation right into a central place within the panorama; their nests. The soil-dwelling termites convey this natural materials greater than a metre deep into the soil,” explains Francis.
The tunnels that termites dig within the soil additionally carry rainwater, containing minerals and dissolved inorganic carbon, by means of the mounds and finally into groundwater or underground aquifers.
The analysis workforce found that though the Namaqualand termite mounds had been as much as 120km from the ocean, the sulphur isotopes they contained, like dimethyl sulfide (DMS) produced by ocean phytoplankton, matched these from fog and marine sources.
Yolandi Ernst, a researcher on the Wits World Change Institute, says rain falling inland can deposit marine aerosols that may include soluble minerals.
Calcite, a type of calcium carbonate, can accumulate on soil and vegetation over time and with heavy rainfall, break down and launch carbon dioxide. Termites sequester the carbon dioxide from the calcite deposits when transporting the soil and plant materials underground of their mounds, maintaining it from being launched into the ambiance.