The Amazon and other tropical forests play a crucial role in storing carbon, helping combat climate change. But recent findings suggest Brazil’s cerrado wetlands might be even more effective. A study in New Phytologist revealed that these wetlands can store around 1,200 metric tons of carbon per hectare—up to six times more than the Amazon on average.
Led by Larissa Verona, this research involved collaboration with various institutions, including the State University of Campinas and the Max Planck Institute. This study is groundbreaking as it dives deep into soil analysis, exploring depths of up to four meters. Previous studies only looked at the surface and often missed 95% of the total carbon present.
The findings indicate some carbon in these soils is incredibly old—averaging around 11,000 years, with some organic material dating back over 20,000 years. “Once this carbon is lost, we can’t easily replace it,” Verona warns.
The cerrado is the second-largest biome in South America, covering 26% of Brazil. It’s known for its rich biodiversity and is vital for the major river basins, including those feeding the Amazon. Amy Zanne, a co-author of the study, explains that the wetland’s humid conditions slow down plant decomposition, which allows more carbon storage.
However, the cerrado’s role in climate stability is often overlooked. Zanne points out that its carbon stock hasn’t been factored into climate calculations until now. The expansion of agriculture and draining wetlands pose serious threats. When these wetlands dry out, the stored organic matter breaks down quickly, releasing harmful greenhouse gases like carbon dioxide and methane into the atmosphere.
Research suggests that about 70% of greenhouse emissions from these ecosystems occur during the dry season, when soil moisture declines. With hotter temperatures ahead, more stored carbon may soon be released.
The cerrado is under increasing pressure from agriculture. Wetlands, often drained for farming, are being severely degraded. Despite laws aimed at protecting these areas, many have suffered damage. Verona emphasizes that while Brazil focuses on protecting the Amazon, the cerrado is often sacrificed for agricultural needs.
To add context, a 2022 report noted that Brazil’s agricultural sector contributed about 25% of the country’s greenhouse gas emissions. This statistic highlights the conflicted priorities facing the nation. Advocating for greater protection of the cerrado is essential. As Zanne states, “It’s crucial for its large long-term carbon stocks—and we must protect it.”
For more insights, you can explore the New Phytologist study here.
