Diversity and Volume Assessment of Tree Species in the Tropical Forest at Obanla, Akure, Nigeria

Abstract

This study focused on the assessment of tree species diversity and abundance at The Federal University of Technology, Akure Tropical Forest Obanla. The research was carried out from May, 2019 to September, 2019. Complete enumeration sampling was adopted for the data collection and all trees with diameter at breast height (Dbh) above 0.1 m were identified and measured. Other tree growth variables, such as diameter at the base (db), diameter at the middle (dm), diameter at the top (dt) and the total height were all measured for volume estimation. Ricinodendron heudelotii Hd the highest number of stems (13), so it was the dominant tree species.The result shows that mean tree volume ranges from a minimum of 0.26 m3 for Olalaceae family, to a maximum of 77.70 m3 for Euphorbiaceae family. Ceiba pentandra of Malvaceae family had the highest mean volume (14.62 m2) while the lowest was recorded for both Khaya senegalensis and Newbouldia laevis with a volume of 0.13 m2. The family of Euphorbiaceae was regarded as the dominant family in the natural forest with 26 tree species which is the highest in this study and with the highest volume (77.70 m2). Shannon Wiener diversity index and species equitability index according to Pielou’s of 3.24 and 0.92 were respectively obtained for the study area. This study revealed the efficacy of an undisturbed natural forest in in situ conservation. Active regeneration can be carried out for proper stocking of the forest so has to make it a potential biodiversity hotspot.