Reconstructing Holocene Vegetation History Through Palynological Analysis of Archaeological Deposits in Ondo State

Palaeoecological reconstruction from archaeological deposits provides critical data for understanding the long-term dynamics of human-environment interaction in the West African forest zone, yet palynological studies from archaeological contexts in Ondo State remain extremely limited despite the state's position within a key forest-savanna transition corridor. This study reconstructs Holocene vegetation history through systematic palynological analysis of sediment columns extracted from two stratified archaeological sites in Ondo State, representing contrasting ecological positions within the forest margin zone. Pollen samples were processed using standard acetolysis and HF treatment methods at the University of Ibadan Palaeobotany Laboratory, with a minimum analytical resolution of two hundred grains per sample. Results from the combined columns span approximately eight thousand years, revealing three major vegetation phases: a more forested phase in the early Holocene consistent with regional humid climatic reconstruction; a forest contraction phase centred around four thousand years before present corresponding with the mid-Holocene dry period documented across West Africa; and a third phase from approximately three thousand years before present showing both forest recovery and the first clear anthropogenic pollen signals including grass expansion and disturbance taxa. The anthropogenic pollen signal predates the earliest ceramic evidence from the same deposits by approximately five hundred years, suggesting initial human landscape modification through burning or clearance preceded the introduction of food production technologies. These findings contribute empirically to ongoing debates about the relationship between climate change, forest availability, and the adoption of agriculture in the Nigerian forest zone. Keywords: palynology, Holocene vegetation, Ondo State, forest-savanna transition, human-environment interaction.