Angola peatlands four times larger, raising conservation concerns

A new research has found that Angola’s central highlands contain at least four times more peat than previously estimated, highlighting the need to protect wetlands that regulate water supplies, store carbon and support communities across southern Africa.

The study, published in Philosophical Transactions of the Royal Society B, estimates that between 8,600 and 11,100 square kilometres of the 380,382-square-kilometre Angola Highlands Water Tower could contain peat.

Researchers said the findings provide the clearest picture yet of peatlands in the region and could help governments determine where to direct conservation funding and guide decisions on agriculture, infrastructure and water use.

The highlands are the source of several major African rivers, including the Zambezi, Congo, Cuanza, Kunene, Cuito and Cubango. The Cuito and Cubango rivers eventually join and flow into the Okavango Delta, a major wetland system in Botswana.

Freshwater systems originating in central Angola support millions of people and economic activity across Angola, Botswana, Democratic Republic of Congo, Mozambique, Namibia, Zambia and Zimbabwe.

Peatlands are waterlogged ecosystems that accumulate partially decomposed plant material over thousands of years, storing large amounts of carbon while regulating water flows and providing habitat for wildlife.

The researchers said the newly identified wetlands store groundwater during the rainy season and release it gradually, helping maintain river flows during dry periods.

But many of the peatlands are located in valley bottoms and along rivers where farming is widespread or near areas targeted for major development, including hydropower, commercial agriculture and the Lobito Corridor.

Drainage, repeated burning or other disturbance could cause the peat to lose its ability to regulate water and release carbon accumulated over thousands of years into the atmosphere.

“Protecting these wetlands is not about stopping development, it’s about using science to help guide where agriculture, infrastructure, and other investments can best be located,” said Sekgowa Motsumi, KAZA Landscape Director for The Nature Conservancy and a co-author of the study.

He said most of the peatlands appeared to be functioning naturally, giving Angola an opportunity to protect them before degradation makes conservation more costly.

“Angola should not carry this burden alone,” Motsumi said, noting that the wetlands provide benefits beyond the country’s borders.

Mapping previously overlooked wetlands

The study mapped the entire Angola Highlands Water Tower at a resolution of 10 metres, using satellite imagery and computer models to identify characteristics associated with peat, including persistently wet soils, vegetation that remains green during the dry season and flat, groundwater-fed valleys and floodplains.

Researchers combined the satellite analysis with samples from 51 peat deposits collected during five field expeditions between 2019 and 2023.

Access to some sites was complicated by landmines left from Angola’s civil war, requiring assistance from demining specialists from the Halo Trust.

The researchers estimate that at least 8,662 square kilometres of the study area almost certainly contains peat, while the area could reach 11,167 square kilometres when areas with less certain evidence are included.

The estimates are significantly higher than earlier assessments based on global datasets that lacked the resolution to identify narrow, groundwater-fed peatlands along many of Angola’s river valleys.

“This mapping effort shows communities, governments, and other conservation leaders where action can be taken to safeguard them,” said Mauro Lourenco, the study’s lead author and a geospatial ecologist at Wild Bird Trust and the National Geographic Okavango Wilderness Project.

He said peatlands could shift from absorbing carbon to becoming sources of greenhouse gas emissions if they are poorly managed.

The researchers cautioned that the map is probabilistic rather than a definitive inventory. Further fieldwork will be required to confirm peat deposits, determine their depth, quantify carbon stocks and assess their condition.

Development and conservation

The findings add urgency to efforts by Angola and conservation partners to protect the Angola Highlands Water Tower as a foundation for water security, climate resilience and sustainable development.

The Nature Conservancy is supporting Angola’s National Source Water Protection Strategy and advising on climate policy, including discussions around incorporating peat carbon into the country’s Nationally Determined Contributions under the Paris Agreement.

The organisation is also working with communities in the highlands and downstream areas to map freshwater habitats, establish locally managed freshwater reserves and develop management plans that protect ecosystems while maintaining livelihoods.

Researchers are also examining whether changes to the timing of traditional fires used for livelihood activities could reduce greenhouse gas emissions.

The study says Angola’s peatlands cannot be considered in isolation. Their formation and continued functioning depend partly on intact upland miombo forests, which influence local climate and water cycles, and Kalahari sand aquifers that store groundwater.

Protecting peat therefore requires maintaining the wider landscape of forests, wetlands and underlying water systems.

Peatlands cover about 3% of the world’s land surface but hold roughly one-third of global soil carbon, making their protection increasingly important as governments seek to reduce greenhouse gas emissions and strengthen climate resilience.

The research was facilitated by The Nature Conservancy, with funding from the Bezos Foundation and Grantham Foundation and through Okavango Eternal, a partnership between National Geographic and De Beers via Wild Bird Trust.