Diversity and volume assessment of tree species in Ahmadu Bello University, Botanical Garden in Samaru – Zaria, Kaduna State, Nigeria

Abstract

The study focused on the volume assessment of tree species diversity and abundance at Ahmadu Bello University Botanical Garden in Samaru, Zaria. The research was carried out from June 2023 to July 2023. The use of a quadrat line transect sample technique was employed, where by three (3) 30m x 30m plots was laid, all tree species with DBH > 0.1m that fell on the transect line was enumerated, height was measured using Haga altimeter, DBH was also measured using diameter tape for volume estimation. Baulunia monandra kurz had the highest number of stems (15), so it was a dominant species. The result shows that mean tree volume ranges from a minimum of 0.86m³ for Bignoniaceae family, to a maximum of 92.45m³ for Malvaceae family Bombax pentandrim. L. Malvaceae family had the highest mean volume (92.45m³) while the lowest was recorded in Tacoma stans (L) juss.ex kunt with a volume of 0.86m³. The family of Fabaceae was regarded as the dominant family in the botanical garden with 23 tree species. Shannon Weiner Diversity index and species equitability index according to Pielou’s of 1.16 and 0.53 were respectively obtained for the study area. This study revealed the efficacy of a partial disturbed Botanical Garden in in-situ conservation. Active regeneration and enrichment planting can be carried out for proper stocking of the Botanical Garden so as to make it potential biodiversity hotspot especially in Northern Guinea Savannah Eco- region.