The study was led by Larissa Verona, a technician working with senior scientist Amy Zanne at Cary Institute of Ecosystem Studies and a former graduate student at Universidade Estadual de Campinas in Brazil, where she carried out the work.

The study is the first in-depth assessment of carbon stocks in the Cerrado's groundwater-fed wetlands, known locally as campos úmidos (wet grasslands) and veredas. Measurements indicate that the peaty soils of these wetlands store about 1,200 metric tons of carbon per hectare.

"This value is about six times greater than the average carbon density of biomass in the Amazon rainforest," said Verona.

Based on the team's mapping of potential wetland distribution, they estimate that these areas could be storing the equivalent of about 20% of the carbon in the Amazon vegetation. However, much more work at additional sites is necessary to test this estimate.

Verona's work was supervised by senior author Rafael Oliveira, an ecologist at Universidade Estadual de Campinas.

A vital ecosystem

The Cerrado is the second largest biome in South America, occupying 26% of Brazil. The most biodiverse savanna in the world, it is home to parrots, toucans, pumas, tapirs, maned wolves, giant anteaters, and many other animals, as well as more than 4,000 native plant species.