ABSTRACT Tree and shrub diversity plays a crucial role in maintaining ecosystem stability, enhancing biodiversity, and providing essential ecological services. This study assesses the diversity, abundance, and distribution of tree and shrub species in the Federal Capital Territory (FCT), Nigeria, with a focus on understanding the implications for biodiversity conservation and land use management. Data were collected through systematic field surveys and analyzed to determine species richness, dominance, and ecological patterns across various land-use types. The results reveal significant variations in species composition and abundance, influenced by anthropogenic activities such as urban expansion, agriculture, and deforestation. Native species, including Azadirachta indica, Parkia biglobosa, and Vitellaria paradoxa, were observed in decline due to habitat fragmentation. In contrast, exotic species such as Gmelina arborea and Tectona grandis showed higher dominance in plantations and urban areas. The study emphasizes the urgent need for sustainable land-use policies and afforestation initiatives to conserve native biodiversity and mitigate the ecological impacts of urbanization. Findings from this research provide valuable insights for policymakers, conservationists, and urban planners to enhance biodiversity conservation efforts in rapidly developing regions like the FCT. Keywords: Tree diversity, Shrub species, Biodiversity conservation, Land use changes.