Comparison of air pollution tolerance indices (apti) of selected plants in three areas in Metro Manila.

Abstract

The study aimed to evaluate and compare the Air Pollution Tolerance Indices (APTI) of seven tree species in three sites in Metro Manila: Philippine General Hospital (PGH) Parking Lot, Ninoy Aquino Parks and Wildlife Center (NAPWC), and University of the Philippines Diliman (UPD). The species selected were Chrysophyllum cainito, Gmelina arborea, Swietenia macrophylla, Mangifera indica, Pterocarpus indicus, Sandoricum koetjape, and Terminalia catappa. The APTI was determined by measuring the leaves’ relative water content, total chlorophyll content, ascorbic acid content, and leaf extract pH. Results showed that all species are sensitive to air pollution with S. koetjape being the most sensitive while M. indica being the least sensitive. This may be due to the high levels of air pollution in the areas. Analysis by Kruskal-Wallis test showed a significant difference in the APTI measured in the three sites and further post-hoc tests showed that the significant difference observed is due to the significant difference in the APTI measured in NAPWC and UPD which may be due to differences in their environmental conditions. It is recommended that known tolerant species be planted in these areas to serve as bioaccumulators of air pollution while the species studied may serve as bioindicators.