A comparative study of air pollution induced stress tolerance of selected tree species in a disturbed and undisturbed plant community

Assessment of Air Pollution Tolerance Index (APTI) of selected 10 tree species found in vicinity of quarrying area in Thelliyoor (Pathanamthitta dist., Kerala) was done. Based on the selected dominant trees from disturbed site, same tree species were spotted from a undisturbed area of St. Thomas College, Kozhencherry Campus. Present study showed the impact of air pollution on ascorbic acid content, chlorophyll content, leaf extract pH and relative water content. These separate parameters gave conflicting results for same species. However the Air Pollution Tolerance Index (APTI) based on all four parameters has been used for identifying tolerance levels of plant species. The order of tolerance was as follows: Mangifera indica Linn. < Cinnamomum iners Blume. < Polyalthia longifolia Sonn. < Syzygium samarangense Blume. < Hevea brasiliensis Willd. < Psidium guajava Linn. < Artocarpus hirsutus Lam. < Garcinia gummigutta (L.) Roxb. < Swietenia macrophylla King. < Tectona grandis Linn.