Assessment of the ecological status of the Central District (Saint-Petersburg) on the basis of ecophytoindication

Abstract

A study of the greenspace in the Central district of St.-Petersburg found the basic elements of Fe, Cr, Ni, and Pb pollution in an association of elements isolated by factor analysis. Species-specific factors related to the accumulation of trace elements lie in the fact that leaves and bark of lime (Tilia cordata Mill.) have high a content of a majority of the above elements. Zn and Cd are accumulated in organs of the poplar (Populus x berolinensis Dippel.). Ratios of the microelement content for the city/control are: for lime leaves — Fe (9,4), Pb (5,3), Cr (4,7), Zn (4,6), Cu (4,5); for poplar leaves — Cd (6,3), Pb (5,5), Fe (4,7), Zn (3,7), Cr (3,2); for lime bark — Cu (15,9), Fe (9,6), Pb (7,5), Cr (5,8), Ba (5,5), Ni (5,1); for poplar bark — Cu (9,6), Fe (5,5), Pb (4,9), Ba (3,9). Analysis of summarized pollution indicators showed that the leaves of the trees represent seasonal pollution of the urban environment and characterize it as medium and high. The bark of the trees, however, accumulating pollutants over many years, reflects a medium, high, and very high level of pollution in the district (for lime bark 54 % of samples characterized a very high level of pollution). Spatial distribution of contaminants is very patchy, due to the particulars of anthropogenic impact and the history of development in particular areas. It is noted that plants exposed to the highest load are those on streets with heavy vehicular traffic loads. Refs 10. Figs 4. Tables 1.