For many years, quarries have been used for mining, changing the landscape of many regions as a result. Many environmentalists have spoken negatively about this, but once it became clear that quarries are home to many rare organisms, the debate about their negative impact on nature has diminished (Talento et al. 2020). Abandoned quarries are characterized by low levels of biomass productivity and quantity of resources, due to extreme abiotic environmental conditions (Roberts and Mattoo 2018). Due to the fact that people are trying to increase the productivity of the land, extreme conditions are becoming increasingly rare. The early successional phase, dominated by rare representatives of the flora, requires special attention among researchers (Hattermann et al. 2018). Given that quarries are an important part of the country's economic activity, it is assumed that they can increase biodiversity in certain regions, which is especially important in densely populated areas (Wang et al. 2018).
In both natural and semi-natural habitats, soil and vegetation and associated physicochemical processes are the two main components of terrestrial ecosystems (Hölzel et al. 2016). An important factor controlling the nutrient cycle in soils for the primary production of plant communities is the consistent availability of nutrients for plant growth (Skálová et al. 2015). However, when used in agriculture or forestry, individual parameters are often insufficient to monitor soil degradation, desertification, and effective reclamation of soil substrate in post-industrial territories. Factors affecting nutrient availability in soil are the first parameters to be considered for assessing soil quality and restoring substrate function while renovating ecosystem function (Comerford 2005). Soil particulate fraction characteristics are the principal indicators of soil-vegetation system feedback (Spohn 2020). Several soil-vegetation relationships have been studied in more detail, including interactions between some tree species, desertification, and soil erosion (Wijitkosum 2020).
Knowledge of the relationship between soil physicochemical properties and vegetation functions that develop spontaneously in post-industrial zones is limited (Pourbabaei et al. 2020). These relations include the regulation of water infiltration and its availability for a specific plant community, as well as for the whole ecosystem (Fischer et al. 2014). Most studies examine the role of particulate fraction and soil properties in post-industrial sites in the rehabilitation process (Halecki and Klatka 2021).
Several studies have analyzed the effect of the soil particulate fraction on the stability of the soil vegetation system due to regeneration processes (Spohn 2020). The significance of the fine fraction in soil processes has been demonstrated in numerous studies (Comerford 2005; Halecki and Klatka 2021; Hölzel et al. 2016). Compared with soil in natural and semi-natural ecosystems, the relationship between soil particulate fractions, water, and nutrient availability, and spontaneous feedback of vegetation in post-industrial sites is much more complex. It also needs to be analyzed for practical restoration purposes.
The process of regeneration of quarries is a fairly slow process, which can take years (Krüger et al. 2017). Limited nutrients and the physical condition of the soil are the main factors affecting the development of flora in areas of abandoned quarries (Hong et al. 2019). The restored community must be capable of developing natural processes without human intervention (Lugo 2020). The recovered ecosystem must resist stress and include a set of native species (Garófano-Gómez et al. 2017). Plant species should grow in rock conditions, in soils with low nutrients and water content, in soils with very high or conversely low pH values or in areas located on steep slopes. In connection with soil disturbances in quarries, the succession of plants is slow, demanding up to several centuries, especially for forest vegetation. Therefore, it is necessary to evaluate all possible approaches to the restoration of abandoned quarries, taking into account changes in the ecological role and biodiversity of fauna.
In this study, a more general approach was taken to evaluate the relationship between the size of coal mine tailings soil particles and the diversity of forest vegetation that developed during spontaneous succession. Many samples allowed classifying the soil of vegetated areas according to the predominant proportion of particles (stone, gravel, sand, silt) on the research site. Considering that open pit landfills are characterized by significant differences, including age, this work aimed to study forest vegetation in open pits of different ages on the territory of the Russian Federation and the Republic of Kazakhstan. This constitutes the novelty of the work.
This included the following tasks:
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selecting open-pit landfills of different ages and climatic conditions to investigate the peculiarities of their soil formation;
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identifying the main physical and chemical properties of the soil;
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analyzing the diversity of forest vegetation species in the landfills studied for future comparison.