Diversity, abundance, and conservation status of indigenous tree species in Binyaminu Usman Polytechnic, Hadejia, Jigawa State, Nigeria

Abstract

Indigenous tree species play an important ecological and socio-economic role in rural communities in Jigawa State. The study assessed the diversity, abundance and conservation status of native tree species at the Binyaminu Usman polytechnic in Hadejia, Jigawa. The site was divided into four sections and a full enumeration of native tree species with a diameter of more than 10 cm was made. The findings revealed 550 individual trees, of which 11 species were found in the arsenal of eight botanical families. The Fabaceae family was dominant with 36.4% species, while the other families Ebenaceae, Meliaceae, Zygophyllaceae, Malvaceae, Mimosaideae, Rhamnaceae and Arecaceae each accounted for one species each (9.1 each). The Shannon-Wiener Diversity Index calculated at 3.81 indicates a high diversity of species and a balanced distribution. However, most species have been classified as rare, vulnerable or endangered on the basis of the IUCN Red List and the GBIF. Notably, the highest relative density was found in the genus Acacia (30.0), while species such as Diospyros mespiliformis and Tamarindus indica had very low densities (0.36). The study recommends urgent conservation measures, including strict rules against cutting down native trees of more than 10 cm in diameter, annual plantation, and awareness campaigns to promote the environmental value of native trees. This effort is necessary to avoid further loss of biodiversity and to ensure the sustainable management of vegetative resources on the site. The study provides valuable input for biodiversity conservation and land-use management in semi-arid regions of Nigeria.