Roadside Trees as Bioindicators: Air Pollution Tolerance and Physiological Responses in Dhaka, Bangladesh

Air pollution presents a significant threat to both human health and plant life. While air pollution in Dhaka has been widely studied for its effects on humans, its impact on plants remains underexplored. This investigation aimed to assess the effects of air pollution on selected plant species in Dhaka, Bangladesh, by evaluating Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). Five tree species-Mangifera indica, S. mahagoni, Polyalthia longifolia, Ficus religiosa, and Artocarpus heterophyllus-were examined to evaluate their tolerance and suitability for pollution-affected environments by determining APTI and API across traffic, industrial, and control locations. The results showed strong species differences: M. indica was considerably tolerant, A. heterophyllus and S. mahagoni showed moderate tolerance, and P. longifolia and F. religiosa had low performance, making them unsuitable for highly polluted areas. M. indica showed the highest total chlorophyll content (TCC) values in industrial and the highest relative water content (RWC) indicating its superior resilience to pollution. This research demonstrates that selected roadside trees can serve as effective bioindicators and help guide plant choice for greenbelt development and urban environmental management.