Function of roadside vegetation in protection of soil from automotive environment pollutants: a case study of zinc / Rola zieleni przydrożnej w ochronie gleb przed motoryzacyjnymi zanieczyszczeniami środowiska na przykładzie cynku

Road dust is one of the most toxic substances found in the environment. Numerous reports found in the literature confirm that proper plantations of various plants can protect areas surrounding communication routes. This way, spreading of different pollutants, including heavy metals, is limited. Determination of total and available zinc content in soil of roadside and soil of a parcel directly neighbouring the roadside on which Virginia mallow was cultivated, plantations of which were supposed to fulfil a function of a biological road screen, was the aim of the investigation. Content of zinc in particular parts of Virginia mallow was also determined. Obtained results of the investigation indicate that content of zinc in soil, on which Virginia fanpetals was cultivated, was similar to its content in soil of roadside directly adjacent to the road. In a course of two years of conducting the investigation, no decrease of the element was observed in the soil of both experimental plots. Moreover, the highest content of zinc was noted in leaves, which are the part of the plant most exposed to automotive pollution, lower in roots and the lowest in stems of investigated Virginia mallow plants.