Soils that formed on the Earth’s surface thousands of years ago and that are now deeply buried features of vanished landscapes have been found to be rich in carbon, adding a new dimension to our planet’s carbon cycle.
The finding, reported today (May 25, 2014) in the journal Nature Geoscience, is significant as it suggests that deep soils can contain long-buried stocks of organic carbon which could, through erosion, agriculture, deforestation, mining and other human activities, contribute to global climate change.
An eroding bluff on the Great Plains reveals a buried, carbon-rich layer of fossil soil — which could contribute to climate change, according to new research.
Photo: Joseph Mason
“There is a lot of carbon at depths where nobody is measuring,” says Erika Marin-Spiotta, a University of Wisconsin-Madison assistant professor of geography and the lead author of the new study. “It was assumed that there was little carbon in deeper soils. Most studies are done in only the top 30 centimeters. Our study is showing that we are potentially grossly underestimating carbon in soils.”