Microbial Community on Leaf Surfaces of Broad-Leaved Alder(Alnus nepalensis D.Don) and Needle-Leaved Khasi Pine(Pinus kesiya Royle Ex Gordon) as Influenced by Atmospheric Dry Deposition of Roadside Pollution in Eastern Himalayas

Impact of roadside pollution on the population of leaf surface microorganisms of Alnus nepalensis D. Don and Pinus kesiya Royle Ex Gordon was studied at a hilly terrain in Eastern Himalayas. Changes in the population of microbes especially fungi and bacteria due to roadside pollution was noted. Leaves were collected at sites 8 m and 1 km away from the National Highway No. 44 and were analysed for microbial population, heavy metals and sulphur accumulation. Leaves of both tree species closer to the road contained higher amounts of heavy metals than those at 1 km site. The population of bacteria and most fungi species was higher at 1 km site than the site closer to the highway. Diversity of micro fungal community in phylloplane at the two sites differed significantly. Counts of fungal units (cfu) and bacteria propagules showed significant negative correlation with the concentrations of metals and sulphur. Some fungal forms including Fusarium oxysporum, Mortierella sp. and Aureobasidium pollulans were abundant in the polluted roadside compared to other species of fungi.