Roadside Vegetation in and Around the Megacity of Kolkata Along an Urbanisation Gradient

Combustion of fossil fuels by the on-road vehicles is major contributor of air pollution which affects the surrounding vegetation and their habitat in addition to human health hazards. Study on the concurrence between vehicular greenhouse gas emissions and associated plant community is important to assess the present day problem scenario on environmental equilibrium. An ecological analysis has been carried out from five locations along roadside of the suburban interiors to the highly vehicle congested urban areas of Kolkata megacity. Quantitative study on naturally grown road side vegetation covering seedlings of tree and shrubby species, herbaceous annuals and perennials along the suitable length of each study area was conducted following standard methodology. Increasing vehicular pollution shows reciprocal correlation with species richness and species diversity. From community structure analyses across the emission gradient it was revealed that a few species exhibited tolerance to withstand increasing air contamination by successful population growth. Nevertheless, the present study might be worthwhile in assessing ecological status of the local plant communities subjected to varying level of vehicle traffic.