Efektivitas Jalur Hijau Jalan Dalam Mengurangi Polutan Gas No2 Di Jalan Tol Jagorawi

Abstract

Commonly, every big cities has a lot of factories and a high amount of vehicles that contribute to the air pollution which can lead to the decreasing of urban landscape quality. NO2 pollutant which is emitted by vehicles on the road can be reduced by modifying a landscape such as utilization of roadside vegetation. The aim of the research was to analyze the NO2 concentration distribution and also to analyze the effectiveness of Mahoni (Swietenia macrophylla) and Glodogan Bulat (Polyalthia fragrans) in reducing NO2 pollutant concentration in the air. This research was conducted in three different parts of the roadside vegetation of Jagorawi highway, there were plot I which vegetation was Mahoni (Swietenia macrophylla), Plot II which vegetation was Glodogan Bulat (Polyalthia fragrans), and Plot III which did not has trees (control). The canopy density of Mahoni vegetation (Plot I) and Glodogan Bulat vegetation (Plot II) were analyzed by Leaf Area Index (LAI) Method using Hemisphericalview Canopy Analyzer and measured by HemiView2.1 Canopy Analyzer software. NO2 concentrations were analyzed by Griess-Saltzman method performed by Inviromental research center, Bogor Agricultural University. The purpose of leaves sampling of Mahoni and Glodogan Bulat vegetations at the highway and BUPERTA (as a control) conducted on August 27th and September 27th in 2015 was to analyzed total N content on leaves as an indicator of NO2 absorption in the air. Total N content on leaves were analyzed by Kjendhal Method at Agronomy and Horticulture (AGH) Laboratory. The results of the analysis showed the distribution of NO2 concentration at Plot I (Mahoni) declined 52.1% and 84.8% in distance of 10 and 30 m respectivety. Meanwhile, the NO2 concentrations at Plot II (Glodogan Bulat) rise at 10 m distance on the percentage of 21.1% and declined at 30 m distance on the percentage of 18.1%. Plot III declining of NO2 concentrations tend to be consistent at a distance of 10 m at 49.4% and 30 m at 43.3% from the pollutant source. The absorption effectivity of NO2 by Mahoni was greater than control in the amount of 41.4% and also was greater than Glodogan Bulat in the amount of 66.7%. The results of Leaf Area Index (LAI) measurement showed that Glodogan Bulat has a higher canopy surface than Mahoni. However, Mahoni effectiveness of NO2 absorption was better than Glodogan Bulat. This was reinforced by the increasing of difference in the percentage of total N of Mahoni leaves which were higher than Glodogan Bulat leaves.