Assessment of Tolerance Levels to Air Pollution for Some Species of Trees and Shrubs Growing on Roadsides in Western Mosul City

Abstract

: This study was conducted in the western part of Mosul city from 20/9/2020 to the end of spring 2021 to assess the tolerance of some trees and shrubs against air pollution based on the air pollution tolerance index APTI. The sites were tested according to the different traffic density and human activities, and included areas Residential, main and secondary roads, samples of healthy leaves were collected for 19 species of trees and shrubs in the season of summer, winter, spring and autumn, and included some evergreen species such as orientalis Biota, Nerium oleander, Cupressus sempervirens var pyramidalis, Cupressus sempervirens var.horizantalis, Casuarina equistifolia, Olea europaea, Eucalyptus camaldulenses, Pinus brutia, Dypsis lutesens, Washingtonia filifera, Tamarix articulate, Callistemon viminalis, Leucaena leucephala, And falling leaves, Melia azedarach, Morus alba, Ziziphus spina-christi, Ficus carica, Albizia lebbeek, Populus euphratica. . Some biochemical characteristics were used to evaluate the ability of these species to resist pollutants and the possibility of using them for planting on the roadsides. Analysis of variance and LSD test were used to find out the statistical differences between the different species. The results of this study indicated that there was a significant difference between the different species, as a result, the highest value of the relative moisture content of the callistemon viminalis trees in the Al tayaran area was (87.461%) among all other plant species, the Leucaena leucephala trees contained a high percentage of chlorophyll, reaching (1.3375 mg/gm) at a probability level (p ≤ 0.01) and it was significantly superior to all other species in different locations, in addition to the highest value found for ascorbic acid in Nerium oleander leaves, which was (0.6377 mg/g) at (p ≤ 0.01) and significantly outperformed all other trees in different sites, while Morus alba trees had the highest pH value (6.8683) and outperformed most of the other species in different sites. The APTI values for all species ranged between (9.067 and 6.505) and callistemon viminalis trees had the highest APTI value among all roadside plants and were significantly superior to most other species in different locations, also Morus alba at Al tayaran region was tolerant to air pollution.