Abstract

The study compared ambient air quality between trees and ornamental plants in Calabar Metropolis, Cross River State Nigeria. Data were gathered using primary sources (collection of air quality data: CO, PM_2.5, PM₁₀, SO_2, and NO₂) using Aeroqual series 200 gas samplers. Data obtained were analyzed using tables, simple percentages, and the Independent Samples Test. The results obtained showed content of CO was comparatively lower under trees (3.97ppm), but high around ornamental plants (5.03ppm) indicating that trees sequester more CO in the environment than ornamental plants. Except for SO₂,the levels of CO, NO₂,PM_10, and PM_2.5 were relatively lowunder tree canopies than around ornamental plants. There was a considerable variation in the concentration of pollutants at different times of the day. Based on the findings, the study recommended among several others that more trees should be planted across Calabar Metropolis mostly around areas dominated by ornamental plants to help reduce the concentration of CO and particulate matter. The planting of trees will increase the rate of carbon sequestration thereby reducing the amount of CO in the atmosphere.

Keywords: Air quality, Trees, Ornamental plants, Calabar Metropolis