Comparative assessment of Tree species as ecosystem indicator of heavy metals accumulation in calcic chernozems on the SFU’s botanical garden

Abstract

The article presents data on the accumulation of heavy metals in calcic chernozems, as well as in the leaves and needles of certain woody plant species: white poplar (Populus alba L.) and boxelder maple (Acer negundo L.), Crimean pine (Pinus nigra var. pallasiana D. Don) and Norway spruce (Picea abies (L.) H. Karst.), growing on the territory of the deciduous and coniferous trees nursery of the Southern Federal University’s Botanical Garden. The calculated values of concentration coefficients (Kc) for soils under deciduous and coniferous trees indicate a low level of soil contamination. Both deciduous and coniferous species exhibit a barrier mechanism for the entry of heavy metals, characterized by selectivity with respect to chemical elements, which is shown through the coefficients of biological absorption of heavy metals. According to the accumulation intensity, heavy metals in deciduous species can be arranged in the following series: Zn Pb Cu, while in coniferous species the sequence was found to be Zn ≈ Cu Pb. In the accumulation of metals by deciduous trees, the participation of the leaf surface is more significant, hence the inversion of lead and copper in the series of metals accumulation by deciduous trees, caused by the of lead particles being airborne and partially collected by the leaves’ surface.