Keefektifan dan Toleransi Jenis Tanaman Jalur Hijau Jalan dalam Mereduksi Pencemar NO2 akibat Aktivitas Transportasi

Abstract

Transportation is an important source of anthropogenic air pollutants including carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2). Vegetation has long been known to have the ability to absorb these pollutants through gas exchange processes. A number of works to investigate plant capability in absorbing NO2 have been reported in several literatures; however, information on plants tolerance to NO2 is very limited. The objectives of this study attempt to infer the effectiveness and tolerance of specified local plants in reducing NO2 through a sequence of laboratory and field experiments, which is primarily to investigate NO2 based nitrogen, and explore distributional patterns of NO2 in specified plants. Plant species are chosen from a variety of greenbelt trees and through the analysis of total ascorbate which suggest the selection of eight greenbelt trees species. They are Pterocarpus indicus, Lagerstroemia speciosa, Casuarina sumatrana, Delonix regia, Gmelina arborea, Cinnamomum burmanii, Swietenia macrophylla, and Mimusops elengi. The capability of plants to absorb and the translocation NO2 are analyzed from experiment using labeled nitrogen (15NO2). Fields experimental data are collected from a highly polluted location around midway of Jagorawi highway and a relatively unpolluted area of Sindangbarang field station. Relative growth rate and physiological parameters recorded include height, leaf area, total ascorbate, total chlorophyll, leaf-extract pH, and relative water content. Relative growth rate is calculated from measurements of plant heights and leaf areas, while plant physiological data are presented as APTI (Air Pollutant Tolerance Index). Tolerance of plant species is calculated based on the relative growth rate obtained previously. Distributional patterns of NO2 and plants capability in absorbing NO2 are derived from measurements of NO2 concentrations in both the uncovered and covered locations.