Analysis of Plant Community Responses to Varying Fire Regimes in Guinea Savanna Woodlands of Kogi State, North Central Nigeria

Fire is a dominant ecological driver in Guinea Savanna ecosystems, yet the effects of varying fire frequency and season on plant community composition and structure in Kogi State woodlands remain poorly documented. This study analysed plant community responses to different fire regimes across experimentally managed fire plots established in collaboration with community rangers in Kogi State. Twelve plots were assigned to three fire frequency treatments: annual early dry season burning, biennial burning, and fire exclusion, replicated four times. Vegetation was assessed before fire treatment commencement and after three years, measuring herbaceous and woody species composition, cover, biomass, and species diversity indices. Tree sapling recruitment and growth were tracked in permanent sub-plots. Results showed fire exclusion led to significant increases in woody shrub density and declining grass cover, consistent with bush encroachment. Annual burning maintained high herbaceous diversity but suppressed woody sapling recruitment below 30 centimetres height. Biennial burning supported the highest overall plant species richness and intermediate tree recruitment, suggesting it most closely replicates the fire regime under which the savanna community evolved. Rare geophytic forbs were more abundant in annually burned plots. The study provides experimental evidence for prescribed burning guidelines in Kogi State woodland management and recommends biennial late dry season burns as the default fire management prescription for biodiversity maintenance in Guinea Savanna protected areas. Keywords: fire regime, Guinea Savanna, plant community, Kogi State, prescribed burning.