Assessment of Vegetation Changes along an Urban-Rural Gradient in Maiduguri Metropolitan Council, Borno State

Urbanisation profoundly alters vegetation structure and composition, and understanding these changes along an urban-rural gradient in Maiduguri, the largest city in North East Nigeria, provides important insights for urban greening policy. This study assessed vegetation changes along a transect spanning the urban core, peri-urban, and rural zones of Maiduguri Metropolitan Council. Vegetation plots (20m x 20m) were established at 12 locations distributed across the gradient. Plant species richness, vegetation cover, stem density, and Shannon-Wiener diversity were recorded. Soil organic carbon, bulk density, and pH were also measured. A total of 83 plant species were recorded across all zones, with the rural zone contributing 71 species, the peri-urban zone 55 species, and the urban core 34 species. Species richness and diversity declined significantly from rural to urban (H' = 3.18 to H' = 1.62). Native tree cover declined from 47% in the rural zone to 11% in the urban core. Exotic ornamental and ruderal species comprised 61% of urban plant records. Neem (Azadirachta indica) was the dominant planted tree across all urban areas. Soil organic carbon correlated positively with native plant diversity (r = 0.74). The study concludes that urbanisation in Maiduguri is driving significant native vegetation loss, and recommends a municipal urban biodiversity policy that prioritises native species planting in public and institutional grounds to restore ecological connectivity.

Keywords: urbanisation, vegetation changes, urban-rural gradient, Maiduguri, plant diversity