In recent years, unsatisfactory condition of trees planted along the borders of the Botanical Garden of the Komarov Botanical Institute RAS was noted. Studies were carried out to determine the cause of tree oppression using physiognomic and biogeochemical methods. Visual signs of the state of trees gave the worst indicators for trees growing on the periphery of the garden. Also near the roadway there are higher concentrations of Na+ and Cl– ions in the soils and in the tree crust, and in the crust of the linden they are 2–4 times higher than the background ones. Soil contamination with heavy metals (HM) is confined to the eastern part of the garden, where high concentrations of Mn, Zn, Pb and Cd are noted. The content of HM in the leaves of the trees does not significantly exceed the background values. The content of HM in the tree crust significantly exceeds the background valuesfor all studied elements, except for Mn and Co. The main pollutants are Pb, Cu, Ni. High values of the total indicator of contamination of the tree crust are noted both on the periphery of the garden and in its center, which indicates that it is impossible to differentiate the garden area by the level of HM contamination. Pollution of the environment by salts in the outskirts of the garden manifests itself more strongly, exerting a stressful effect on woody vegetation, however, in each specific case, the inhibition of trees can be intensified by the action of additional causes (flooding, diseases, etc.).
Keywords: biogeochemistry, botanical garden, Botanical Garden of the Komarov Botanical Institute RAS, heavy metals, heavy metals soil contamination, physiognomic signs of tree oppression, salinization, trees in botanical gardenAll articles can be accessed under Creative Commons Attribution 4.0 International Public License (CC BY 4.0).