Biogeochemical lichen indication study of formation and temporal changes of Oleksandriia Arboretum atmospheric pollution

Abstract

Using the method of biogeochemical lichen indication the levels of the average long-term content of K, Ca, Al, Fe, Mg, Na, Mn, Zn, Sr, Ti, Ba Cu, B, Pb, Ni, V, Cr, Co, Cd, Se, Sb in surface air were measured on the territory of Olexandriia Arboretum and adjacent territories (Bila Tserkva, Kyiv Region, Ukraine). The purpose of the study is to determine the state and dynamics of the atmospheric geochemical field on the territory of Olexandriia Arboretum and its surroundings. The method of biogeochemical lichen indication based on the values of micro- and macroelements content in epiphytic lichens was used as a research tool. Application of the ICP-OES spectroscopy method allowed the analysis for chemical elements content of the samples of epiphytic deciduous Parmelia sulcata, Xanthoria parietina and bushy Evernia prunastri lichens collected in 2009 (20 points) and 2021 (23 points). In order to identify possible sources of entering of certain elements into lichens the researchers used the factor analysis method, i.e. a method of principal components with Varimax factors rotation. Six obtained factors represent: the impact of land cover (the most significant factors F1–F3) and man-made components (minor polygenetic, factors F4–F6). As a factor's number decreases, its partial explanatory variance decreases too. Factor F1 represents a common dust loading on the atmosphere with a predominance of the terrigenous component (mostly coarse-dispersed particles). Factor F1 is responsible for the dust-aerosol loading that is largely caused by the microclimatic circulation of the city breeze type thus forming a peculiar atmospheric and geochemical association that consists of chemical elements related to the building industry and building materials production. Powerful, however, local (impactful) atmospheric man-made influences manifest themselves through factor F3. Minor factors' discrimination ability reduces if a source of atmospheric pollution is less significant. Both division of factors into subfactors and noticeable temporal dynamics are observed more often. For instance, factor F4 has two geochemical sub-associations affected by the impact on the Olexandriia's landscapes of the 1990s' ecological disaster (fall-out of oil products, geochemical marker – V) and galvanic waste causing soil pollution (Zn, Mg, Cr, Ni and Ti), as well as discharges of agricultural enterprises (K). One of the peculiarities of F4 is a gradual decrease in its intensity over time. Factor F5 should be interpreted as the only load on the environment associated with galvanic pollution with cobalt being replaced by copper as a leading pollution marker. We suggest considering Factor F6 as a factor associated with oil pollution only.

Keywords

• lichens
• biogeochemical lichen indication
• macro- and microelements
• heavy metals
• air pollution
• factor analysis
• оlexandriia arboretum