Variation in Stomatal Density and Air Pollution Tolerance in Invasive Asteraceous Species of Assam in Response to Cement Particulates

Air pollution is nothing less than havoc in modern developing countries. With new buildings going into construction or are finished each day, there is an increased demand of cement. Jorhat is the fastest developing district of Assam. Owing to the construction needs the cement storage facility of Chinnamara was established in an otherwise remote undisturbed environment. This has resulted in an area where air is filled with amorphous cement particles surrounding the facility. Local vegetation either fails to survive in the area or are sparsely distributed surrounding the area. However, some invasive Asteraceous species like Mikania micrantha, Spilanthes acmella and Ageratum conyzoides were frequently distributed in that area. The study was intended to understand their dominance over other vegetationin that area. Leaves of the aforesaid plants were collected from the cement polluted area their stomatal density was compared with the leaves of the same species from an area polluted with dirt and an area free of any dust pollution. Air Pollution Tolerance Index was used to understand their high adaptability to the polluted environment. Results concluded that all the three plants significantly increased their stomatal density in response to cement particulates. However, M. micrantha bore the highest stomatal density. Air pollution tolerance indices indicated that S. acmellahas greatly adapted itself to the cement particle polluted environment when compared with the other two plants. Studies of stomatal density and APTI values in invasive species in relation to air pollutants also presented itself as an efficient tool for biomonitoring cement particulate pollution in a definite area.