Abstract:
The main purpose of the study is to establish the total content of an association of heavy metals (Cu, Pb, Zn, Ni, Mn, Co, Cr), which are prioritized in the organized background monitoring of the natural environment. The study was conducted in the soils of the landscapes of Milevska and Chudinska Planina, located in the Kraišten Natural Geographical Region of Bulgaria. Field and laboratory studies were conducted on the collected soil samples from different horizons of brown (Cambisols) and mountain-meadow soils (Umbrosols), as well as an integral sample of anthills in characteristic landscapes of the two mountains. The interpretation of the obtained results shows a relatively increased content of trace elements Zn (149.6 mg/kg), and to a certain extent Pb (19.16 mg/kg), compared to other soils from different regions of the world and mountainous territories of the South-West Bulgaria. In some parts of the region, the soil diversity is also due to a relatively high content of lithomass in the soil profile, which is differentiated differently for each soil type. Geochemical spectra were made to establish the soil-forming rock-soil relationship, as well as the degree of differentiation of microelements in the soil horizons. The relationship between the lithogeochemical features and the soil cover is weak to moderate and is related to the specific conditions of soil formation and the established small ore occurrences in the two mountains. The association of trace elements Cu, Ni, Mn, Co, Cr is distinguished by relatively low average contents in the studied soils and confirm the background character of the studied areas in the mountains. This applies both to brown forest soils (Cambisols) and to upland-meadow soils (Umbrosols). The results of the research can be used in the construction of complex ecological monitoring in the area of the two mountains.