Tropical deforestation in the Congo Basin is releasing carbon that has been held in the soil for thousands of years, according to new research.
The Congo Basin is the second-largest rainforest on Earth and is quickly being deforested for agriculture and charcoal production. A team of researchers at Florida State University conducted a study to understand what could happen to the 20 billion tons of carbon stored in the forest’s soil.
The team took samples of river water from 19 sites in the region, looking at the radiocarbon age and chemical makeup of dissolved carbon, which leaches into the rivers from nearby soil. They found that pristine forests are leaking young carbon that plants were using for photosynthesis, but carbon escaping in deforested sites was about 1,500 years old.
This means that carbon that was once stable, stored in deeper parts of the soil, is being surfaced and lost. However, the researchers say it is too early to say exactly how much old soil carbon has escaped.
The team is working to better quantify carbon losses from forest soils, and is extending its work to the Congo’s central lowland forests.
Although stopping deforestation would be the best way to avoid this carbon loss, Earther says that finding other ways for the growing population of Congo to use the forests and educating farmers about techniques they can use to protect their soils, could also help.