Peculiarities of migration and accumulation of heavy metals in the system «ground-plant» by the example of the National natural park «Beloberezhye Svyatoslava»

Abstract

Heavy metals like ekopolyudanty have a high capacity for bioaccumulation, toxicity and significant mobility in the environment. Since the bulk of the land is plants, it is important to identify the processes of migration and accumulation of heavy metals in them. But keep in mind that the level of heavy metal accumulation in plants of different taxonomic groups are not the same. Cumulative capacity of plants depends on many factors: the type of soil, humidity, altitude, meteorological characteristics of the region and landscape, and more. It should be noted that the migration of heavy metals from soil to plants depends on the concentration of mobile forms in soil. Once the soil heavy metals are constantly migrating, moving to some form of chemical compounds. Although soils are characterized by resistance to chemical contamination due to its ability to accumulate and neutralize ecotoxicants. But it is significant accumulation in soil heavy metals leads to lower pH of the soil and destroys the soil-absorbing complex. The object of study in this paper selected park «Biloberezhzhya Svyatoslav» which Presidential Decree Ukraine in 2009 was granted the status of National Park «Biloberezhzhya Svyatoslav», so the park is virtually unexplored. The aim is to study the phenomenon of bioaccumulation of heavy metals in soil and plants cover various ecotheitons and their influence on the processes of human transformation in these florocomplexes. For the past 10 years the National Park is undergoing significant anthropogenic pressure on transport, recreation, hotels and aggressive recreational activities. So one of the important aspects of solving the problem is to provide control and accounting of vehicles, which enters the territory of spit and emission monitoring (especially heavy metals) which makes transport and monitoring of soil and vegetation that will characterize the current state of ecosystems National Park «Biloberezhzhya Svyatoslav» and anticipate negative processes that occur in ecosystems of different levels. To study the vegetation of the National Park «Biloberezhzhya Svyatoslav» that is able to accumulate heavy metals in significant quantities were selected samples of the dominant plant species in various microflorocomplexes. For more detailed specifications the transformation of these substances in the soil and their translocation in plants and soil samples were taken at a depth of 20 cm. In the study the accumulation of heavy metals in soils contributes primarily low acidity (neutral and slightly alkaline pH) soil horizons in gleying cuts low values ​​of redox potential and high content of amorphous hydroxides Fe. The remaining soil parameters – a low content of organic matter, light texture, low cation exchange capacity value (ECO) soil absorbing complex, a high redox potential – are unfavorable factors for the accumulation of heavy metals in soils. Analysis of mobile forms of heavy metals in the soil studied florocomplexes showed that the majority of indicators does not exceed the MCL. This minimum figure for cadmium Li, Aln, Qbp, apparently caused by acidity (pH) of the soil. Overall indicators of cadmium in florocomplexes studied ranged from 0 to 0.7 mg / kg. The maximum amount of cadmium in Mar (0,6 mg / kg), Rap (0,7 mg / kg) and only they exceed the MCL level that caused considerable indirect influence, since these florocomplexes heavy metals fall on the Dnieper River from cities and businesses located upstream. Indicators of copper in florocomplexes fluctuate within 0.5–4.0 mg / kg, thus exceeding the MCL only Mar (3,2 mg / kg), Rap (4,0 mg / kg), which reduces the enzymatic activity of soil. Similar figures have nickel 0.5–5.0 mg / kg, exceeding the MCL in Mar and Rap. Number of lead in the top layer of soil depends not only on the human impact, but also from iron oxides, which can form complexes with Lead. As he studied florokompleksah ranges from 0.8–3.8 mg / kg, and not exceeding the MCL. The maximum of the number of zinc – 2.5–7.1 mg / kg, which is caused by the structure of the parent rock, characterized by a large number of iron oxides and pH in which it is possible absorption of lead hydroxide. However, no figure does not exceed the MCL. So low rates of bioaccumulation factors indicate a low level of accumulation of heavy metals in soils of ecotheitons of National Park «Biloberezhzhya Svyatoslav», i.e. minor processes of human impacts on natural ecosystems. Sandy soils are characterized by low absorptive capacity, and a weak hold heavy metals except molybdenum and selenium. Because plants easily adsorb them, some of them even in very small concentrations have a toxic effect. So exceeded MPC Dominant Mar, Rap – Zoctera marina L. and Ruppia cirrhoza (Petagma) Grande. indicate intense indirect human impact on water florocomplexes that are part of the National Park «Biloberezhzhya Svyatoslav» because these florocomplexes heavy metals fall on the Dnieper River from cities and businesses that are located upstream. The lowest coefficients of accumulation in the soil and in plants characteristic of Hy and Lst, which is caused by geographical barriers that protect them from human activity. For values of absorption coefficients biotic can conclude not only the role of individual species of plants and vegetation in the whole cycle of elements in the ecosystem, but also the ecosystem’s ability to cleanse itself. In florocomplexes of National Park «Biloberezhzhya Svyatoslav» is obviously particularly important role in the self-cleaning from heavy metals play the genera Phragmites Trin. ex Steud. and Zoctera L., both because of the high intensity of the absorption element (Zoctera L.), and because of the high biomass of these species in communities (Phragmites Trin. ex Steud.). Among the analyzed dominant species, growing on uncontaminated and contaminated areas revealed two species hiperakumulyatory heavy metals – Phragmites australis (Cav.) Trin. ex Steud and Zoctera marina L. addition to those of the common species that accumulate significant biomass and have relatively high rates of accumulation of Cd, Zn, Pb, – a species: Grindelia squarrosa L., Salicornia prostrata Pall., Poa angustifolia L., which can be recommended as objects of future field experiments.