Scientists have discovered the world's oldest tropical peatland still in existence in the Upper Kapuas Basin in Indonesia's part of Borneo. Radiocarbon dating of peat cores there showed that the peat dome in West Kalimantan, a province of Indonesia with about 1.7 million ha of peat, could have started forming at least 47,000 years ago.
Radiocarbon dating is a technique commonly used to date archaeological finds such as fossils.
The study was led by researcher Monika Ruwaimana, who is from the ethnic Dayak Mualang from West Kalimantan and a doctoral student at the University of Oregon. The findings were published in scientific journal Environmental Research Letters earlier this month. Ms Ruwaimana said the discovery was surprising, as the oldest temperate peatlands are between 10,000 and 11,000 years old.
Tropical peatlands are considered younger, with the oldest thought to be around 7,000 years old. "We predicted that the peatland in the upper river region will be older; however, we did not expect it to be 47,000 years old," she added. As the dated cores did not extend to the bottom of the peat, it could have started forming even earlier, she noted.
"This peat is quite deep at between 17m and 18m, which means it is an important carbon sink," she said. "As peat is formed layer by layer like kueh lapis (a traditional snack), by analysing each layer, we can predict how the climate, fire and vegetation at that time were like," said Ms Ruwaimana.