The content of Cd and Pb in undeveloped and shallow soils and plant material in the area of national park Tara

Abstract

Ultramafic (serpenites) are a group of igneous or metamorphic rocks, which are characterized by high concentrations of Mg, Fe, Ni, Cr, and Co, along with low concentrations of Ca, P, and K, contain less than 45% silicon (SiO2). Tara Mountain is natural good of western Serbia where areas under serpentinites occupy 28%. Researchers agree that the flora of serpentine areas is unique and botanically very important. The specificity of the flora and the development of vegetation on serpentinites are characterized by special mechanisms of plant species adaptation to increased concentrations of some heavy metals in the soil with low content of essential elements (nutrients). This paper examines the influence of serpentinite geological substrate on the occurrence of certain plant species in the initial stages of plant community development. The soil was mainly sampled in rock crevices in the early phases of soil development (Lithosols) where the influence and origin of the metals from the rock can be considered the most obvious. Content of cadmium (Cd) and lead (Pb) in geological substratum, soil and plants biomass is analysed in order to differentiate levels and extents of natural and anthropogenic pollution and also deposition data from the EMEP program (European Monitoring and Evaluation Programme). Results show that the content of lead and cadmium in the soil and plant samples are higher than the content in the corresponding rock sample, except for two soil samples, in which the content of Cd is lower. Thissuggest that the origin of the increased Pb and Cd content might be from anthropogenic sources. Deposition (data from EMEP program) of Cd and Pb, which was analysed for the period from 1990-2018, indicate significant cumulative effect. The values of cumulative deposition in research area have a value of 91,51 kg/km2 lead, while the value of cadmium is 1665 g/km2 , which classifies NP Tara in above-average polluted area in R. Serbia.