Vegetation Survey and Carbon Stock Estimation in Olokemeji Forest Reserve, Ogun State, South West Nigeria

Forest reserves in South West Nigeria play a significant role in regional carbon sequestration, yet their above-ground carbon stocks remain poorly quantified. This study conducted a vegetation survey and estimated above-ground carbon stocks in Olokemeji Forest Reserve, Ogun State, using standard forest inventory methods. Systematic plots were established across three vegetation strata representing high forest, degraded forest, and plantation areas. Tree diameter at breast height and total height were measured for all woody plants exceeding five centimetres diameter at breast height. Allometric equations developed for West African tropical forests were applied to estimate above-ground biomass and carbon stocks. Results showed highest carbon density in high-forest compartments, averaging 182 tonnes of carbon per hectare, while degraded zones averaged 67 tonnes per hectare. Plantation areas containing exotic species had intermediate carbon densities but lower species richness. Floristic analysis identified sixty-four tree species across all plots, with Triplochiton scleroxylon and Cola gigantea among the most abundant in high forest areas. The study demonstrates the conservation value of protecting remaining high-forest compartments and restoring degraded zones through indigenous species enrichment planting. These findings contribute to Nigeria's national forest carbon inventory and support REDD-plus programme planning in the South West geopolitical zone. Keywords: carbon stock, forest inventory, Olokemeji Forest Reserve, above-ground biomass, REDD-plus.