ACCUMULATION OF HEAVY METALS IN THE SOIL – PLANT SYSTEM IN THE CITY OF YOSHKAR-OLA

Abstract

Pollution of environmental components with heavy metals is currently an acute environmental problem, which is most clearly manifested in urban ecosystems. For analysis, a coniferous species, common in the landscaping of the streets of Yoshkar-Ola, was chosen – Picea pungens Engelm. The research goal is to analyze the content of heavy metals (Pb, Cd, Cu, Fe) in the soil and vegetative organs of the P. pungens growing in the conditions of Yoshkar-Ola. In three functional zones of the city of Yoshkar-Ola (the Republic of Mari El), which differ in the degree of anthropogenic load, the total content of heavy metals was determined in soil samples, in shoots of the second order and in needles of the second year of life of P. pungens. Also, the ash content of the vegetative organs of prickly spruce was analyzed. The biological absorption coefficients and biogeochemical activity coefficients were calculated for P. pungens. Statistical processing of the obtained results was carried out using Microsoft Excel and Statistica 6. In the soils of the studied functional zones, there were no excesses of hygienic standards for lead, copper and iron, but the content of cadmium was somewhat higher (1.1 APC) in the industrial zone. The ash content and heavy metals content both in shoots and needles of plants growing in the industrial zone were the highest. The coefficient of biological absorption of Pb, Cd, Fe in P. pungens in all areas of Yoshkar-Ola was less than 1.0, which indicates a low intensity of their absorption. According to the series of biological absorption, Pb and Cd in the organs of P. pungens belonged to the elements of weak accumulation and medium capture, and Fe, to the elements of weak accumulation and medium capture, as well as to the elements of weak capture. The biological absorption coefficient of copper was above 1.0, indicating that it was a highly accumulative element. The biogeochemical activity of P. pungens was the highest in the recreational area of the city.

Keywords

• picea pungens engelm.
• soil pollution
• urban ecosystem
• shoots
• heavy metals
• needles