Ecological evaluation of dominant roadside plants through APTI and API for sustainable green belt development in cosmopolitan city (Lahore) of Pakistan

Keeping in view the potential role of plants in pollution abatement, reclamation of urban forest cover and carbon sequestration, fifteen (15) plant species growing along 7 busiest roads in the city of Lahore were ecologically evaluated using analytical tools such as Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). Leaf area, dust content, ascorbic acid content, total chlorophyll content, relative water content and pH of leaf extract were determined along with some morphological, biological and socio-economic parameters of the selected species in control as well as experimental sites and significant variations were noted. S. cumini showed highest dust capturing potential followed by F. benghalensis, F. benjamina, M. elengi, A. scholaris, P. longifolia and F. religiosa. M. indica (APTI = 17.88) was the most tolerant species, E. milii, F. benghalensis and H. rosa-sinensis were intermediate performers (APTI values 11.08, 13.15 and 12.28, respectively) and all other species such as A. scholaris, A. indica, B. spectabilis, C. erectus, E. citriodora, F. benjamina, F. religiosa, M. elengi, M. alba, P. longifolia and S. cumini were assessed as sensitive plants. F. benghalensis and M. indica secured API grade 6 (excellent), A. indica, F. religiosa, H. rosa-sinensis, M. alba and P. longifolia scored API grade 4 (good) whereas API grade 3 (moderate) was associated with A. scholaris, E. citriodora, F. benjamina and S. cumini. The remaining species with API grades 2, 1 and 0 fall into poor, very poor and not recommended categories, respectively. Plants belonging to API rating grades 3 (moderate), 4 (good), 5 (very good), 6(excellent) and 7 (best) are recommended for cultivation in polluted sites.