SCREENING OF SOME ROAD SIDE TREES FOR PLANTATION IN POLLUTED URBAN AREAS OF KATHMANDU, NEPALJAYA PRAKASH HAMAL AND MUKESH K CHETTRIAbstract Kathmandu valley is facing air pollution problem because of rapid increase in vehicular emissions. Some common road side trees like Callistemon lanceolatus, Cinnamomum camphora, Ficus reliogisa, Grevillea robusta, Jacaranda mimosifolia and Populuseuroa mericana were evaluated for their air pollution tolerance index (APTI) and metal accumulation index (MAI). These two indices were measured during winter season at different polluted sites (Airport, Balaju, Banasthali, Basundhara Dhumbarahi and Gongbu) and less polluted site (Narayanthan) in Kathmandu. Air pollution tolerance Index (APTI) ranged from 12.51±0.74 to 15.67±0.75. Highest APTI value was observed in Populuseuroa mericana (15.67±0.75) at Dhumbarahi. The mean value of metal accumulation index (MAI) values ranged from 7.34 to 20.44 and highest MAI value was observed in Populuseuroa mericana (20.44). Correlation of APTI and heavy metal (Cu, Pb and Zn) accumulation in most of the studied tree leaves were negative showing their inverse relationship, which indicated the heavy metal avoidance mechanism among them for their survival. Populuseuro americana, Jacarandamimoisi folia and Callistemon lanceolatus with high MAI and intermediate APTI range are recommended for plantation on road side of Kathmandu. |