Biochemical Changes in Leaves and Physico-chemical Alterations in Rhizospheric soil of Selected Trees Exposed to Vehicular Pollution at Roadsides at Jabalpur, India

Abstract

In many South-Asian countries like India, the metropolitan areas get exposed to high air-pollution due to emissions from vehicles driven by the fossil fuels. This research was aimed to detect the effect of dust and gases from automobile exhausts on foliar biochemical changes of roadside vegetation and in physico-chemical properties of soil at Jabalpur, India. Considering the samples collected from least polluted areas as control set with distinction from roadsides of higher air-pollution as experimental, biochemical analyses from tender leaves were done from five pollution-resistant trees viz. Pongamia pinnata, Dalbergia sissoo, Azadirachta indica, Ficus religiosa and Cassia siamea for total carbohydrate, nitrogen, calcium, sodium, potassium, magnesium, phosphorus, ascorbic acid and phenol. Between the control and experimental samples, for few parameters like sodium and potassium assays, minimum differences in values were found, while for the others, remarkable differences were evident, which might have been happened due to physiological processes like damage-due-to-air-pollutants or resistance-and-protection-to-air-pollutants or for the both. For rhizospheric soil, physico-chemical analyses were done for pH, bulk density, electrical conductivity, cation-exchange capacity, organic carbon, available nitrogen, available potassium, available phosphorus, exchangeable potassium, exchangeable sodium, exchangeable calcium and exchangeable calcium and magnesium. All results both for foliar and soil analyses were expressed as mean values in replicates of 3 samples. Amongst the interesting findings, the following were noted like the pH was found to be higher in Pongamia pinnata, Azadirachta indica and Ficus religiosa, the available nitrogen higher in Pongamia pinnata, Ficus religiosa and Cassia siamea in the polluted samples. For some important individual elements and compounds, the findings have provided a index-guideline indicating their absorption and assimilation with the nutrient molecules. The findings are significant in relating plantation-schedules and monitoring programs in many crowded and polluted cities in tropical South Asian countries.