Paleoenvironmental Dynamics in Central and West Africa

The landscapes of Central and West Africa have undergone dramatic shifts driven by changes in climate, vegetation and human land use over the Quaternary. Periods of intensified monsoon rainfall fostered expansive rainforests, while arid intervals saw the retreat of forest taxa and the spread of savannah. Wetland systems in the central Congo Basin accumulated vast peat deposits that record alternations of carbon accumulation and loss in response to water-table fluctuations. Pollen records from lakes and swamps reveal forest–savannah mosaics developing under millennial-scale hydroclimatic oscillations, often modulated by migrations of the Intertropical Convergence Zone. Archaeological and genetic evidence traces the emergence and spread of agriculture from around 5 000 years ago, with local intensification, crop diversification and landscape engineering reshaping ecosystem services. These interacting natural and anthropogenic forces have left an intricate archive of sedimentary, isotopic, palynological and genomic proxies, informing our understanding of vegetation resilience thresholds, carbon-cycle feedbacks and the socio-economic adaptations that buffer communities against climatic stress. The global significance of this region lies in its large tropical carbon reservoirs, biodiversity hotspots and the long-term human-environment interactions that offer lessons for sustainable land management today.

Research from Nature Portfolio

Recent studies have demonstrated that peat carbon stocks in the central Congo Basin lie close to a climatic drought threshold. Analysis of peat cores shows that a drying trend between 7 500 and 2 000 years before present led to enhanced decomposition of older peat layers, while a stabilisation of hydrology after 2 000 years ago allowed renewed accumulation. Hydrogen-isotope measurements of plant waxes provide a direct proxy for palaeohydrology, linking regional moisture decline to carbon-cycle feedbacks under late Holocene conditions.

Genomic investigations of rainforest hunter-gatherers and agriculturalists in West-Central Africa have shed light on the demographic impact of early farming. Genome-wide data indicate that substantial admixture between foragers and farmers occurred only within the last millennium, suggesting that the spread of agriculture involved gradual socio-economic exchanges against a backdrop of pre-existing ecological and demographic differentiation.

Paleoenvironmental Dynamics in Central and West Africa publication trend

The graph below shows the total number of articles in paleoenvironmental dynamics in central and west africa across all publications each year (not limited to Nature Index journals).

Technical terms

Palaeoenvironmental proxy: An indirect indicator—such as pollen, isotopes or charcoal—used to reconstruct past environmental conditions.

Peat core: A stratified column of partially decayed vegetation from wetland sediments that archives changes in carbon accumulation and local hydrology.

Hydrogen isotope (δ2H): The ratio of deuterium to protium in organic molecules, employed to infer past rainfall and moisture sources.

Genomic admixture: The mixing of distinct ancestral populations detected through patterns of DNA variation, reflecting historical population interactions.

References

1. Hydroclimatic vulnerability of peat carbon in the central Congo Basin. Nature (2022).
2. The impact of agricultural emergence on the genetic history of African rainforest hunter-gatherers and agriculturalists. Nature Communications (2014).
3. Diversification, Intensification and Specialization: Changing Land Use in Western Africa from 1800 BC to AD 1500. Journal of World Prehistory (2019).
4. Agricultural diversification in West Africa: an archaeobotanical study of the site of Sadia (Dogon Country, Mali). Archaeological and Anthropological Sciences (2021).