Analysis of charcoal from an archaeological assemblage near the Lukula community located at the southernmost boundary of the Mayombe forest (Bas-Congo, DRC) yielded 30 taxa used as firewood between 1,200 and 700 cal. b.p. Local people mentioned 71 taxa preferred for use nowadays. The identified taxa belong either to mature rainforest, pioneer forest, regenerating forest or woodland savanna, indicating that ancient and current local populations gathered firewood in several different forest types. Modern firewood preferences do not seem to agree with the archaeobotanical composition. Also, linguistic evidence does not indicate a long exploitation history for all of the recorded taxa. Furthermore, no particular wood qualities such as wood density, calorific value or magical or medicinal properties seem to determine the Lukula assemblage, which was probably composed of waste material from various activities which required different specific firewood characteristics. As such, taxa composition is not biased by human selection, suggesting that it reflects the surrounding environment, which was characterised by mature rainforest with patches of regenerating forest and open vegetation types. Unlike the origin of present-day forest-savanna mosaics from human activity, fragmentation around 1,000 cal. b.p. may have been provoked by a well-known climatic event coinciding with the Medieval Climate Anomaly, which undoubtedly had a significant impact on Central African forest composition.