Efficiency of Pinus nigra J.F. Arnold in removing pollutants from urban environment (Plovdiv, Bulgaria).

Abstract

The aim of this study was to assess the efficiency of urban vegetation in removing pollutants from the environment using Pinus nigra J.F. Arnold as a model tree. For this purpose, the concentrations of some heavy metal and potentially toxic elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, U, and Zn) in needles, branches, and roots of P. nigra, as well as in the surrounding soil, have been analyzed and the removal capacity has been estimated on the basis of element translocation. The relationship between ecosystem services provisioning and plant well-being was also analyzed through physiological (photosynthetic pigment content and ratio) and anatomical (leaf injuries appearance) indicators. Enrichment factor, translocation factor, bioaccumulation factor, and index of translocation were calculated in order to assess the urban impact and removal efficiency of sampled trees, as well as the general transport of trace elements between the studied plant's organs as results of wet and dry atmospheric deposition. Anthropogenic pollution with As, Cd, and Pb was proven in whole urban environment, so these high values of translocation through pine trees have given an added value to the regulating ecosystem services of urban vegetation. Searching and planting of trees with higher removal efficiency could be crucial for improving quality of urban environment.