The central highlands of Angola are considered fundamental to the country’s and the region’s hydrological cycle, as they generate large amounts of rainfall that run off into the surrounding landscape.
Now, a new investigation reveals that the Angolan highlands, where some of Africa’s largest rivers also originate, may contain at least four times more peatlands than previously thought.
These ecosystems comprise wetlands that store large amounts of carbon, regulate the flows of rivers by absorbing and slowly releasing rainwater, are vital for wildlife, and support the daily needs of millions of people and important economic sectors across several countries on the continent.
A group of researchers, in a paper published in the journal ‘Philosophical Transactions B’, identified thousands more square kilometres of potential peatlands in the central Angolan highlands. By mapping the 380,382 square kilometres (km2) that make up the region, scientists believe that between 8,600 km2 and 11,100 km2 could be peatlands, four to five times higher than earlier estimates, which were not Angola-specific.
Much of these new potential peatland areas were identified in valleys and along rivers with intense agricultural activity, or near areas where infrastructures are planned that will have strong environmental impacts, such as large-scale hydroelectric plants and railways.
If drained or repeatedly burned to make way for these projects and for the expansion of agriculture, peatlands lose their ability to retain and provide water and may even begin releasing the carbon dioxide accumulated and stored for thousands of years into the atmosphere. Once released, this carbon will be difficult to recover.
The researchers say that, therefore, they must be protected from unsustainable activities, drainage and fires, and integrated into climate mitigation and development plans, rather than being viewed solely through the lens of environmental conservation.
“Protecting these wetlands does not mean halting development, but rather using science to help choose the best locations for agriculture, infrastructure, and other investments,” explains Sekgowa Motsumi, of the non-governmental organization The Nature Conservancy and co-author of the study.
The researcher says that, for now, most of the peatlands in the Angolan highlands remain functioning naturally and continue to provide their indispensable services. These services, he notes, are enjoyed by many other countries as well, so they, as well as the international community as a whole, should help Angola protect these ecosystems.
Until now, a large part of the region has been almost invisible to scientists, largely due to the lack of detailed maps that would enable detecting peatlands, many of which are narrow and difficult to detect.
Therefore, the researchers believe that this work, with a detailed map of these ecosystems at a 10-meter resolution, which combined satellite imagery with on-the-ground samples collected between 2019 and 2023, will be essential to protecting them.
“To protect, manage and restore peatland ecosystems we must know where they are and map them,” says Mauro Lourenço, the article’s first author and an ecologist with the National Geographic Okavango Wilderness Project and the Wild Bird Trust.
“Peatlands can shift from carbon sinks to sources if not managed carefully. This mapping effort shows communities, governments, and other conservation leaders where action can be taken to safeguard them,” he emphasizes.
