Assessing biodiversity and floristic composition of tree species in Okomu forest reserve, Edo State, Nigeria

The loss of tree species due to human activities has been on the rise in recent times. This study employed a systematic sampling technique to assess tree species diversity and floral composition in the Okomu Forest Reserve, Edo State, Nigeria. Four-line strips, each 2 km long and 2 m wide, were established at 1 km intervals for this study. A skilled tree taxonomist carefully measured and identified trees with a DBH of 10 cm or greater. Subsequently, the gathered data were utilised to calculate the diversity of tree species and tree composition. The study identified 60 tree species, distributed across 31 families and 56 genera in the study area. Cleistopholis patens, Ceiba petandra, Terminalia ivorensis, and Diospyros insculpta were found to have the highest individual populations of not less than 15 trees per hectare. However, some trees were represented by only one tree per hectare, which is a concern as they are threatened. The three most dominant families were Leguminosae, Annonaceae, and Apocynaceae, comprising six tree species. The Important Value Index (IVI) of 11.15 and 10.05 for Terminalia ivorensis and Ceiba petandra, respectively, show that these two species are more prominent in the reserve.