Assessing the Impacts of Quarrying Activities on Vegetation and Soil Quality in Ogun State, South West Nigeria

Quarrying for granite and laterite in Ogun State supports construction material supply but generates environmental impacts including vegetation clearance, dust pollution, surface drainage alteration, and soil disturbance extending beyond quarry boundaries. This study assessed the impacts of quarrying activities on surrounding vegetation structure and soil quality in three active quarry sites in Ogun State. Vegetation was surveyed using belt transects at 50, 150, and 300 metre distances from quarry boundaries and compared with control transects in undisturbed areas of similar land use. Soil samples were collected at paired quarry-adjacent and control points and analysed for organic carbon, pH, aggregate stability, and heavy metal content. Dust deposition was measured using passive deposit gauges at each distance interval. Results showed significant vegetation structural changes within 150 metres of quarry perimeters, with reduced canopy cover, lower tree species richness, and higher frequency of dust-tolerant ruderal plants. Soil organic carbon was reduced by 38 percent and aggregate stability by 44 percent in quarry-adjacent soils relative to controls. Elevated concentrations of iron and manganese were detected in soils near quarry access roads. Dust deposition rates exceeded guidelines at monitoring points within 100 metres of active quarrying. The study recommends mandatory ecological buffer zones of at least 200 metres around quarry operations, dust suppression requirements, and preparation of post-quarry land restoration plans as conditions of quarry licences in Ogun State. Keywords: quarrying, vegetation impact, soil quality, dust pollution, Ogun State.