Effects of Air Pollution on Urban Plants: Nezahat Gökyiğit Botanical Garden

Abstract

Physiological traits of Fraxinus angustifolia Vahl. in response to different levels of polluted air conditions were analysed in Nezahat Gokyigit Botanical Garden which is located at the intersection of TEM and E5 highways in Istanbul. To determine the level of air pollution at the investigated area, for a 1 year period, monthly passive air pollution (SO2, NO2, O3, VOCs) sampling were conducted at four sampling sites which were chosen as representatives of the whole profile of the botanical garden. Along with air pollution monitoring, some physiological parameters of the leaves of F. angustifolia, − total chlorophyll and carotenoid contents, chl a/chl b ratio, net photosynthesis rate, specific leaf dry weight, water content percentage, leaf area and heavy metal concentrations- were analyzed during the growing period. Also PAH, heavy metal and PCB concentrations of the soil were detected in the nearby area to see the extend of the pollution on the region. While no SO2 pollution was observed, NO2 appeared to exceed the concentration limits that are stated as harmful for vegetation. O3 concentrations dominated in the area during summer. VOC, PAH and PCB concentrations on the soil were found to be related to the traffic pollution. Excessive levels of Fe, Pb and Cd of the unwashed leaves were determined. Among all the pollutants, only NO2, O3, Fe and Cd found to be responsible of plant injury in the area. However the general physiological status of F. angustifolia is not seem to be effected from the urban environment conditions of the botanical garden which can be related to its tolerance mechanisms.