The wetlands of the Cerrado biome store more carbon than the Amazon rainforest.

The wetlands and streams of the Cerrado biome accumulate up to 1.200 tons of carbon per hectare. This value exceeds the average biomass stock of Amazonian tropical forests by about six times.

The carbon present in these soils formed over thousands of years. Dating indicates an average of 11 years, with records approaching 20 years. Accumulation occurs in water-saturated soils, an oxygen-poor environment. This condition reduces the decomposition of organic matter and favors prolonged carbon storage.

Researchers analyzed wetlands and fields in the Chapada dos Veadeiros National Park. The team collected soil samples up to four meters deep. Instruments measured carbon dioxide and methane fluxes throughout the year. Radiocarbon dating revealed the age of the carbon present in the deeper layers.

The data indicate an average carbon density of 1.159 Mg per hectare in the soils of these areas. Approximately 96% of the total carbon remains in the soil. Plant biomass accounts for only 4% of the stock. Organic layers have an average thickness of approximately 1,9 meters.

Remote sensing modeling indicates a large extent of these areas in the biome. Results point to approximately 16,7 million hectares of wetlands in the Cerrado. This value corresponds to approximately 8% of the biome and 2% of the Brazilian territory.

Despite the large carbon stock, these environments show high vulnerability. Changes in the water regime reduce the water table level. Soil drying accelerates the decomposition of organic matter and releases CO₂ and methane. Approximately 70% of annual emissions of these gases occur during the dry season.

Anthropogenic pressures intensify the risk. Agricultural expansion, drainage of wetlands, dams, and intensive water use alter the hydrological dynamics. A survey by MapBiomas indicates that 47% of the Cerrado is under anthropogenic use, predominantly pastures and crops.

Scientists advocate for increased protection of these areas and further mapping of the biome. The loss of peatlands and wetlands compromises carbon stocks accumulated over millennia. Recovering these stocks would require timescales incompatible with human life.

More information at doi.org/10.1111/nph.71027