**1. Introduction**

Environmental protection, natural resource management, ensuring of environmental safety of human life are essential conditions for sustainable economic and social development of the European countries. Among the densely populated areas in the steppe zone of Ukraine,

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Dnipropetrovsk region is characterized by high level of metallurgic and agricultural production. Active mining extraction inevitably accompanied by diminishing of fertility in ordinary and southern chernozem, despite this soil has a great potential for agricultural exploitation. The harmfulness of such processes consists not only in reducing the square of arable land, but also in significant deterioration of ecological status on the entire territory within Dnieper steppe. As a result, increasing rate of coal extraction leads to enlargement of disturbed land area. The most significant changes are taking place with the land fund during development of coal deposits. Under such conditions, the soil cover degraded completely; new forms of relief and landscapes, having fundamental changes of properties and regimes were formed instead. Man-made landscapes connected with the activities of mining and smelting complex often formed by the low-biogenic phytotoxic rocks, this is part of the reason for their low biological productivity [7, 10, 28].

Forest remediation is one of ways for optimization of such technogenic landscapes [1]. According to the modern concept of land remediation, forest remediation is carried out in the absence of reasonability to recycle the land for agricultural use. The main purposes of forest remediation are the forest fund increasing and improvement of environment. Environmentally, the main task of the forest remediation is creation of sustainable forest plantations that have a powerful environment-forming effect on technogenically disturbed sites [4, 8]. Forest remediation is the most effective method to recovery disturbed lands under steppe conditions; after its performing will be a dramatic increase in the forest area of the damaged territory, because the forest provides a reliable water retention, reduces wind strength, redistributes better the summer and winter precipitation, conversion surface runoff waters into deep runoff waters, leveling of temperature regimes, etc. [5].

Since soil is the basis of any terrestrial ecosystem that determines direction of development and features of ecosystem functioning, the rate of its formation determines the rate of recovery of all other ecosystem components and functioning conditions (bacteria, plant and animal communities). Therefore, the efficiency of forest ecosystem recovery can be estimated by the rate of soil formation and environmental properties of the root layer created during the remediation process. We mean soil-forming process as the way of the initial substrate transformation by interaction of all soil-forming factors.

Decomposers, also referred to as reducers, are an important component of any ecosystem [21]. Among the decomposers, soil saprophages play a crucial role; their trophic activity causes environment-transforming (zoo pertinent) effect on artificial forest ecosystem within remediated lands, contributing to destruction of plant debris. They provide the ecosystem services such as waste recycling and detoxification, encouraging improvement of soil environment state. Healthy soil is one of the main conditions needed for successful growth of forest plantings within steppe territory and for maintenance of ecologically sustainable agricultural production. Healthy soil is a key point of condition for successful forest growth; it forms an environment for root zone stimulating of soil biota activity and allows the roots to spread maximally within soil space.

Coal industry activity is considered to be one of the most powerful factors leading to deterioration of natural landscapes variety. Steppe zone of Ukraine comprises a major coal-mining area: the Donetsk Coal Basin (Donbass). When deeply buried deposits of Cretaceous period are moved onto the surface, it initiated the processes of physical weathering, oxidation, dissolution, hydrolysis, and burning. A number of other negative factors are also determined, such as high concentration of soluble toxic salts, heavy metal contamination, alkalinity level rise, low absorbency and permeability, high spoil density, low carbon, and plant-available nitrogen. For example, coal wastes contain organic and mineral substances with a high content of some elements threat to human health (Ni, V, Mn, Cu, etc.); it leads to formation of the phytotoxic flows at water erosion, and strong aerial technogenic pollution at deflation, causing negative effect on all living organisms [22, 23].

Dnipropetrovsk region is characterized by high level of metallurgic and agricultural production. Active mining extraction inevitably accompanied by diminishing of fertility in ordinary and southern chernozem, despite this soil has a great potential for agricultural exploitation. The harmfulness of such processes consists not only in reducing the square of arable land, but also in significant deterioration of ecological status on the entire territory within Dnieper steppe. As a result, increasing rate of coal extraction leads to enlargement of disturbed land area. The most significant changes are taking place with the land fund during development of coal deposits. Under such conditions, the soil cover degraded completely; new forms of relief and landscapes, having fundamental changes of properties and regimes were formed instead. Man-made landscapes connected with the activities of mining and smelting complex often formed by the low-biogenic phytotoxic rocks, this is part of the reason for their low biological

Forest remediation is one of ways for optimization of such technogenic landscapes [1]. According to the modern concept of land remediation, forest remediation is carried out in the absence of reasonability to recycle the land for agricultural use. The main purposes of forest remediation are the forest fund increasing and improvement of environment. Environmentally, the main task of the forest remediation is creation of sustainable forest plantations that have a powerful environment-forming effect on technogenically disturbed sites [4, 8]. Forest remediation is the most effective method to recovery disturbed lands under steppe conditions; after its performing will be a dramatic increase in the forest area of the damaged territory, because the forest provides a reliable water retention, reduces wind strength, redistributes better the summer and winter precipitation, conversion surface runoff waters into deep runoff

Since soil is the basis of any terrestrial ecosystem that determines direction of development and features of ecosystem functioning, the rate of its formation determines the rate of recovery of all other ecosystem components and functioning conditions (bacteria, plant and animal communities). Therefore, the efficiency of forest ecosystem recovery can be estimated by the rate of soil formation and environmental properties of the root layer created during the remediation process. We mean soil-forming process as the way of the initial substrate trans-

Decomposers, also referred to as reducers, are an important component of any ecosystem [21]. Among the decomposers, soil saprophages play a crucial role; their trophic activity causes environment-transforming (zoo pertinent) effect on artificial forest ecosystem within remediated lands, contributing to destruction of plant debris. They provide the ecosystem services such as waste recycling and detoxification, encouraging improvement of soil environment state. Healthy soil is one of the main conditions needed for successful growth of forest plantings within steppe territory and for maintenance of ecologically sustainable agricultural production. Healthy soil is a key point of condition for successful forest growth; it forms an environment for root zone stimulating of soil biota activity and allows the roots to spread

Coal industry activity is considered to be one of the most powerful factors leading to deterioration of natural landscapes variety. Steppe zone of Ukraine comprises a major coal-mining

productivity [7, 10, 28].

waters, leveling of temperature regimes, etc. [5].

278 Soil Contamination - Current Consequences and Further Solutions

formation by interaction of all soil-forming factors.

maximally within soil space.

Among all biota, soil mezofauna plays a crucial role in development of the resistance mechanisms in artificial forest plantations; in particular, representatives of the saprotrophic complex (earthworms) contribute greatly in such process. These invertebrates effect significantly to transformation of soil properties because their tropho-metabolic activities, acting as a biological factor in soil organic farming. Such invertebrates are called 'ecosystem engineers' and are able to influence the habitat and soil biota community through this activity; they can cause ecosystem succession [11, 25]. Among soil invertebrates, earthworms have a leading role in formation of stability mechanisms in soil. As a result of their life activity, earthworms make a significant ecological contribution to transformation of soil characteristics and properties. Tropho-metabolic activity of earthworms is considered to be an important element in formation of soil environmental properties that cause maintaining of buffer properties in artificial soil against copper contamination within remediated areas.

Copper (*Cuprum, Cu*) is the chemical element of the first group in Mendeleev's periodic law. Serial number: 29, atomic mass: 63.54. Copper content in the Earth's crust is about 0.01%. It is found in a free state in the form of nuggets that sometimes attain a large size (up to several tons). However, native copper ore is relatively uncommon, and currently it is produced not more than 5% of copper from the total world production. Copper is a sulphophilous (chalcophilous) element; 80% of it is present in the Earth's crust in the form of compounds with sulfur [6, 12]. The average copper content (according to A. P. Vinogradov and D. M. Malyuga) in the lithosphere is 47 mg/kg, in soil from 6 to 75 mg/kg, in plant tissues from 2 to 70 mg/kg. Among the sedimentary parent rocks, the highest content of copper is characteristic of the loess, loesslike loams and clays of different origin (20–25 mg of Cu per 1 kg of soil), the least – sands (5– 12 mg/kg) [14, 27]. Regional clark of copper in soil of the steppe zone in Ukraine is equal to 27 mg/kg with a range of variation 10–64 mg/kg [3].

The share of mobile forms of copper compounds in the upper horizon of soils of the European part of the CIS countries is on average 10–12% of its total content [29]. Red soil and yellow Podzolic soil are better provided with copper; sandy soil and soil enriched in organic matter contain smaller amounts of copper [15]. Humic substances are involved in the fixation of copper by soil [16]. Copper usually accumulates within the upper soil horizons, reflecting its bioaccumulation and contemporary technogenesis. Contamination by copper is the result of usage of substances containing this element, particularly of fertilizers, agricultural and municipal wastes. Enterprises of nonferrous metallurgy are significant sources of soil pollution with copper, in addition.

Plants accumulate most of copper into their leaves and seeds, less in roots, and very little in stems [13]. Copper is a component of numerous enzymes insuring normal cells functioning; it takes part in process of chlorophyll formation and other oxidation-reduction processes into plant cells. Copper deficiency in plants causes lowering activity of synthetic processes and leads to accumulation of soluble carbohydrates, amino acids, and other degradation products of complex organic substances; such process leads to withering, turgor loss, chlorosis, delayed shooting stage, and poor seed formation [2]. In animals, copper involved in processes of enzyme activation and it is part of the respiratory proteins such as hemoglobin and hemocyanin [22]. Living organisms-concentrators of copper are well known among both plants and animals (tea plant, mollusks, spiders, etc.). Many animals and plants experience toxicity from copper excess [19]. In most cases, trace elements (particularly copper) come to the animals through trophic chains. Considering representatives of saprophages, it should be noted that copper as a trace element is always presented in their body and excreta [17].

The goal of the article was evaluation earthworm (*Lumbricidae*) tropho-metabolic effect in maintaining capacity of remediated artificial soil to resist from copper contamination. This paper determines quantitatively buffer capacity of artificial soil and earthworm casts from copper contamination, and make a comparison of immobilization capacity between earthworm casts and remediated soil. Soil buffering capacity is maintaining the chemical soil state unchanged under the influence of chemical compounds flow. Assessments of rates of *Lumbri‐ cidae* impact on the environment, particularly the effect of tropho-metabolic activity of earthworms on buffer capacity of the remediated soil are of scientific and practical interest in relation to soil fertility management.
