Phytosociology of the Derived Savanna Vegetation in Ekiti State, South West Nigeria

The derived savanna of Ekiti State, representing a transition zone between rainforest and Guinea savanna, supports distinct plant communities that are under-documented relative to the more prominent forest ecosystems of the region. This study investigated the phytosociology of derived savanna vegetation in three sites across Ekiti State representing different anthropogenic disturbance histories. The Braun-Blanquet relevé method was used, with 60 relevés (10m x 10m) distributed across the sites. Cover-abundance values were assigned to each species in each relevé. Community classification was performed using agglomerative hierarchical clustering (Ward's method), and community-environment relationships were assessed using canonical correspondence analysis. Four distinct plant communities were identified: the Andropogon-Hyparrhenia community, the Terminalia-Detarium community, the Chromolaena-Sida community (disturbed), and the Daniellia-Lophira community. The Chromolaena-Sida community was most closely associated with recently disturbed and farmed areas, as confirmed by canonical correspondence analysis. Soil organic matter and moisture were the strongest environmental variables explaining community distributions. Shannon-Wiener diversity was highest in the Daniellia-Lophira community (H' = 3.04) and lowest in the Chromolaena-Sida community (H' = 1.47). The study provides the first phytosociological classification of the derived savanna in Ekiti State and recommends its use as a baseline for vegetation monitoring and habitat management decision-making by the Ekiti State Forestry Department.

Keywords: phytosociology, derived savanna, plant communities, Braun-Blanquet, Ekiti State