5 Factors Affecting the Equatorial African Carbon Cycle in the 21st Century

The tropical rainforests within Equatorial Africa are critical as an area of high biodiversity and globally important roles in the carbon, water, and energy cycles. We review current knowledge and highlight the critical gaps in understanding of its carbon cycle, focusing on five key factors affecting it: climate change, land cover and land use changes, nutrient availability, carbon dioxide fertilization, and legacy effects. We discuss (1) spatially heterogeneous responses to climate change and extreme ENSO events; (2) how expanding deforestation and degradation alter carbon stocks and fluxes, induce edge effects, and fragment animal habitats; (3) how large-scale biomass burning to the regions north and south of equatorial Africa alters nutrient availability through nitrogen and phosphorus deposition; (4) the limited response of forests to carbon dioxide fertilization in site studies versus what models predict; and (5) the role of past (>1000 years) climate and anthropogenic influences on the vegetation that lies within today. Finally,  we briefly compare the differences in forest response to contemporary changes compared to other tropical rainforests.