A Decade of Plant Conservation and Diversity: Eco-Taxonomic Insights from the University of Benin Botanical Garden

In Nigeria, deliberate efforts have been made to conserve plants through the establishment of protected areas, including parks, forests, and botanical gardens. Most tertiary institutions have also established botanical gardens to promote the conservation of plant biodiversity. This study focused on the University of Benin Botanical Garden, analyzing its ecological and economic value after ten years of development. Both quantitative and qualitative assessments of plant species were conducted, including species diversity indices, tree morphometrics, and the influence of tree shade on herbaceous growth, with comparisons drawn between shaded and open areas. A total of 34 tree species across 14 grids were identified and classified into distinct habits and life cycles. Notably, Gliricidia sepium (Fabaceae) was the most dominant tree species, while Asystasia gangetica (Acanthaceae) was the most prevalent herb, particularly under shade. Ecological indices such as Shannon diversity, Simpson index, and Fisher’s alpha were calculated, revealing higher species evenness in shaded grids, with Grid 14 exhibiting the highest evenness index (0.8563). Tree morphometrics showed that Bombax buonopozense recorded the highest trunk volume (149.66 m³). Furthermore, plant species were categorized based on their economic importance, including medicinal, food, cultural, oil-producing, and ornamental values. Elaeis guineensis and Psidium guajava exhibited multipurpose uses across multiple value domains. The findings highlight that botanical gardens serve as vital repositories for conserving plant diversity and cultural heritage, especially in regions threatened by urbanization and environmental degradation. This Botanical Garden demonstrates significant ecological richness and economic relevance, supporting its role as a model for conservation in developing countries.