Background: In the present study, the tolerance of plantain tree species (Platanus orientalis, Morus nigra and Ailanthus altissima) to air pollution was evaluated using Air Pollution Tolerance Index (ATPI) and Anticipated Performance Index (API) index in Isfahan city (Iran). Methods: For this purpose, three dominant trees growing at six stations in Isfahan was selected and then sampling of the tree leaves was performed, after being transferred to the laboratory, the ATPI and API index were calculated. Results: The results of calculating the ATPI in the leaves of M. nigra, P. orientalis and A. altissima species showed that the highest values of ATPI index was obtained in M. nigra at 20.77 and then detected in P. orientalis and A. altissima with the values 14.90 and 14.33 respectively. According to API values Morus nigra had the best performance (Score = 6 so it classified as the Excellent) while P. orientalis and A. altissima had very good and intermediate performance, respectively. Conclusion: According to ATPI and API index most tolerant tree species was Morus nigra, so it would be the most suitable species for plantation programme in urban and pollutant areas followed by Platanus orientalis and Ailanthus altissima. As well as our results suggest that Platanus orientalis and Ailanthus altissima can be used as bio-indicators of air pollution due to their low ATPI scores (lower than 16). The present study suggests that the combination of both the ATPI and API indices for identifying and selection of plant species is very useful for plantation in urban areas.
