Survey of automobile exhaust tolerant plant species in Kano Metropolitan

Abstract

A survey of trees and shrubs exposed to automobile exhaust along Zungero, Dan Agundi and Zaria Roads which are among the major roads in Kano metropolis was conducted in 2021. A green area with natural vegetation (Botanic Garden of Plant Biology Department of Bayero University, Kano) was selected as a control environment. Concentration of air pollutants such as SO₂, CO₂, H₂S, PM₁₀, and NH₃ were detected in the study sites using portable gas sensor manufactured by Crown Detection Instrument Ltd. Oxon OX14DY England while plant survey was carried out using quadrat sampling of 600 x 600m size. The results showed that the concentrations of the air pollutants released in the automobile emission exceeds maximum limits recommended by World Health Organization (WHO) in all the three sites to support biotic health and reproduction. Analysis on plant survey has revealed Azadirachta indica, Calotropis procera, Ficus polita, Albizia labbeck (all exotic species) to be the most abundant and tolerant specie to air pollution. Comparison between the three polluted areas and control (unpolluted) sites also revealed that more plant species were encountered in control site which implies that the automobile exhaust influenced plant diversity.