Work

A probabilistic map of tropical peatlands in the Angolan Highlands Water Tower

Year: 2026

Type: article

Abstract: Peatlands provide critical ecosystem services, including habitat for biodiversity, water purification and climate regulation. Tropical peatlands in Africa present significant knowledge gaps in occurrence and extent estimates, and there is a lack of policy initiatives related to conservation and sustainable management. This study expands on a previous peatland extent estimate for the Angolan Highlands by extending the geographic scope to include the Angolan Highlands Water Tower (AHWT). We identified 51 ground-verified peat locations, using a peat corer, in multiple areas of the region during 5 separate field expeditions conducted between 2019 and 2023. These locations were used to independently evaluate an unsupervised classification model. The model incorporates satellite-derived vegetation and moisture indices (NDVI, NDWI), vegetation stress indices and terrain-based variables (including the Topographic Position Index) that capture key controls on peat formation in the AHWT. We generated a probabilistic map of potential peatland occurrence, estimating that peatlands cover between 8662 km2 (high certainty) and 11 167 km2 (low certainty), or 2.28-2.94% of the AHWT. The map was evaluated against field observations: all 51 ground-verified peat locations fell within areas predicted to have at least 50% peat probability (mean = 85.7%, s.d. = 20.4%). The resulting map offers a baseline for future field validation, carbon stock assessment and conservation planning. A French translation of this abstract is available in the supplementary material. This article is part of the discussion meeting issue 'African tropical peatlands: function, value and vulnerability'.

Source: Philosophical Transactions of the Royal Society B Biological Sciences

DOI: 10.1098/rstb.2024.0481