PHYTOTOXICOLOGICAL ASSESSMENT OF METALS IN PHYTOMASS OF PLANTS IN NATURAL ECOSYSTEMS (ON THE EXAMPLE OF GREEN PARK AREAS)

Abstract

Actuality. Local environment pollution is a factor limiting the survival of many species of living organisms. Plants simultaneously play the role of the main bioaccumulator of metals and the buffer of contamination in ecosystems. Detecting the classical toxicological dependence of the "dose-effect" on the phyto-component of the natural ecosystem is irrational and complicated by the significant bio- and landscape diversity. The metals influence on plants in ecosystems should first be studied systematically in relation to the patterns of distribution of metals in the territorial and species aspect. The most important centers of natural ecosystems in large cities are green parks. Goloseevo-Feofanovskaya and Koncha-Zaspivska green parks are typical natural areas in Kyiv.

Analysis of recent research and publications. Under the influence of metal ions in plants, the metabolism of substances and functional activity are violated, various mechanisms are initiated in order to prevent or eliminate negative changes at different levels: molecular, subcell, cell, organism and population. From the hygienic point of view, metals cause carcinogenic (As, Zn, Cr, Pb, Co, Hg), mutagenic (Cr) and teratogenic (Pb, As, Co, Ni) effects, almost all of them belong to the first and second classes of danger for sanitary-hygienic classification. Plant intoxication can occur as a result of the input of metals to plants by the follicular or root path, and mainly manifested in reduced biomass. The purpose of the study was to provide phytotoxicological assessment of the content of metals in phytomass of plants in natural ecosystems of Goloseyevsky-Feofanivska and Koncha-Zaspivska green areas of Kyiv.

Materials and methods of research. Goloseyevsky-Feofanivska and Koncha-Zaspivska green areas of Kyiv are part of the landscape of elevated hilly-sloping plains on the Paleogene-neogene basis, composed of forest sanded loams.  Thanks to convex relief and loamy soils, studied areas have intensive removing of elements, in particular, anthropogenic pollutants. Both studied parks are located at the junction of the Right-bank Polissya and the Forest-Steppe zones of Ukraine in warm medium-tempered agro-climatic zone. The content of Cd, Co, Cu, Pb, Ni, Pb in the phytomass was analyzed in: Gagea lutea L., Tussilago farfara L., Anemone ranunculoides L., Ficaria verna Huds., Pulmonaria obscura Dum., Stellaria holostea L., Convallaria majalis L., Hypericum perforatum L.. The photosynthetic fraction of the phytomasses of the first and second tier of the trees was analyzed in: Quercus robur L., Carpinus betulus L., Salix caprea L., Tilia cordata Mill., Acer platanoids L.; Trees of the third tier: Sambucus nigra L., Prunus padus L..

Results and discution.  According to Fisher’s criteria the difference between metals concentration in early blooming plants and trees was highlighted. Early blooming plants had considerably higher metals concentration than trees and shrubby species. Among the early blooming plants the Tussilago farfara L. was characterized by highest metals concentration in phytomass. We proposed to use Tussilago farfara L. as indicator of metals presence in the ecosystems of Green park areas. According to the value of Variation Coefficient (V) calculated for the metals concentration in the plant phytomass, the metals are located in the range: Cd> Ni> Pb> Co> Zn> Cu. The regularity of physiological individuality of metals is revealed. Regardless of growth conditions, the highest diapasons of the concentration in plants had ultra-microelements (Co, Pb, Ni, Cd), the lowest diapasons of the concentration in plants had microelements (Zn, Cu). Such lowest diapason of Zn and Cu concentration could be explains by important nutrient role for plants. The physiological role of Co, Pb, Ni, Cd today is not thoroughly investigated. According to metals concentration in phytomass the range of early blossom plant was:  Tussilago farfara L. > Anemone ranunculoides L.> Convallaria majalis L. > Stellaria holostea L. > Hypericum perforatum L.> Pulmonaria obscura Dum. > Ficaria verna Huds. > Gagea lutea L.. The highest concentration of lead (among the tree species of the third tier) was observed for Sambucus nigra L. (5.5 mg*kg^-1 dry matter), which belongs to official medicinal plants. The generative fraction of phytomass of Sambucus nigra L. is traditionally collected as medicinal raw materials. However, there are no uniform hygienic standards for the content of metals in phytomass for medical purposes. Literary data on the availability of hygiene standards are quite controversial. That’s why it is necessity to normalize the metals content in plants which traditionally used as medicines in Ukraine.  Carpinus betulus L. had no significant difference in the content of metals in phytomass of Goloseyevsky-Feofanivska and Koncha-Zaspivska green areas.

Conclusions and perspectives. Metals concentration in the phytomass of early blossom plants was significantly higher than in woody and shrub species. The Acer platanoides L. had being growing near the Goloseevsky avenue (Goloseyevka green park area), had the highest metal content among the studied trees of first and second tier. Among the early grassy herbs, the highest metals concentration was in Tussilago farfara L.. That’s why we proposed to use this plant as indicative of metal presence in the ecosystems of park green zones. The Coefficient of Variation revealed a regularity of the physiological individuality of metals.