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Restoration of postmining areas is a frequently addressed topic requiring a comprehensive view. In this article, the recovery process of selected postmining spoil heap sites was evaluated using an approach based on calculation of Nash equilibrium (NE) probability distributions. Many of these sites have been allowed to recover by spontaneous succession, while on others, a variety of restoration procedures have been tested, most of them variants of the forest plantation type. The evaluation was carried out on selected data from each site that reflects four factors: the richness of the vegetation cover, the amount of biomass as soil macrofauna per unit area, the forestry yield, and the attractiveness for recreation use. The analysis was based on permuted game configurations in which these factors were treated as competing entities, adversaries that were differentially successful in each location depending on the conditions of the recovery procedure used. The game strategies that the factors exhibited as theoretically interacting entities had no primary information content, which meant that they could be treated stochastically. The result was a distribution of the NE probability at each location. Considering the fact that this result reflected the degree of optimality of the included factors, the calculation could be considered as a specific type of multicriteria evaluation, which was practically applicable and provided unambiguous results. The NE probability in sites restored by deciduous tree stands was higher, which was therefore assumed to correspond to higher stability. [ABSTRACT FROM AUTHOR]

We tested the effect of main soil characteristics and tree species on earthworm community composition and abundance in reclaimed spoil heaps planted with five different tree species. Earthworm and soil macroarthropod abundance and biomass were highest in alder plantations, followed by oak plantations. The numbers of soil macrofauna were positively correlated with the total soil N content, which was highest in alder plantation. The correlation was strongest for endogeic earthworms (genus Aporrectodea and Octolasion). Soil moisture, measured in top 10 cm, affected only endogeic species. Other soil variables (pH, Ca) did not have a strong effect on earthworms. The earthworm community composition was similar in alder and oak, with most species occurring at both types of forest; however, in alder forest the epigeic species Dendrobaena octaedra was more common, whilst in oak forest the epigeic earthworms form genus Lumbricus were more abundant (L. rubellus and L. castaneus). The anecic species Aporrectodea longa was more abundant at alder sites, but L. terrestris was more abundant under oak. The alder forest was characteristic by a thick humus layer (10–15 cm), which at oak and larch sites was thinner (4–7 cm) and at pine and spruce stands was absent. Soil compaction was lower under the deciduous trees (alder, oak, larch), than under spruce and pine. We conclude that the alder plantations have most palatable litter and lowest C/N ratio and therefore support the highest numbers of soil macrofauna, which affects the humus layer thickness and soil compaction in the surface layers. [ABSTRACT FROM AUTHOR]

We tested whether wireworms (Elaterid beetle larvae) prefer the expansive grass Calamagrostis epigejos to other early-successional plant species from the spoil heaps in two microcosm experiments and in a field survey of wireworm abundance and C. epigejos coverage on the spoil heaps at different topographic positions at the spontaneously revegetated sites with an undulating surface. In the first experiment, wireworms reduced rhizome biomass of C. epigejos the most out of the belowground organs of the 5 plant species, but did not affect its root biomass. In the second greenhouse experiment, wireworms negatively affected the growth of rhizomes of a growing C. epigejos , whilst they did not affect the other plant species or the aboveground biomass. In the field survey, C. epigejos coverage was lowest at the bottoms of depressions, despite the higher moisture and nutrient levels at this position. Wireworm numbers were the highest in depressions. The results of this study support the hypothesis that wireworms can negatively impact the C. epigejos by feeding on its rhizomes and have the potential to slow down the expansion of this weed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Infiltration and preferential flow were markedly affected by planted tree species. • Litter quality influenced number of earthworms, infiltration, and preferential flow. • Architecture of root system was important for distribution of infiltrated water. • Connections and size of pores were crucial factors for water flow in emerging soil. Soil recovery is crucial for successful ecosystem restoration at post-mining sites. Water infiltration and preferential flow in soil are important but little studied soil characteristics. In this study, we explore effects of tree species on infiltration, geometry of preferential flows, size distribution and origin of pores, and related properties of soil. An experiment was conducted at post-mining sites developing under monocultures of three tree species (alder, oak and spruce) after lignite mining near Sokolov, Czech Republic. A key hydraulic parameter of soil, field saturated hydraulic conductivity (K s), measured in topsoil, was highest under alder (mean value of 6.9 × 10−5 ms−1) and lowest under spruce (mean value of 1.9 × 10−5 ms−1). In subsoil, there were no significant differences in K s between tree species. For the alder site, dye tracer tests showed that water penetrates almost uniformly to the top 15 cm of soil depth and with the greatest lateral flow. In a deeper part of the alder soil profile, preferential flow was concentrated around earthworm burrows and roots, where the two often occur together. Thin soil sections of alder soil show that earthworm casts and burrows substantially contribute to porosity around the roots (59 % of dyed worm-created structures in alder-root microsite). A similar situation was observed in oak, but preferential flows along roots started from the surface and cross section of preferential flow was smaller than in alder soil. In spruce, preferential flow was concentrated around roots and cracks in claystones and the cross section was even smaller. Comparison among the forest stands indicates that overall porosity does not correspond with infiltration of dye tracer and K s , which seem to be more driven by pore size distribution and pore connectivity. This is consistent with larger occurrence of macropores (>300 μm) in alder. The results show that trees affect infiltration and preferential flow in soil by their specific root systems and to a large extent indirectly by effect of litter quality on earthworm populations, which then enhance macroporosity and pore connectivity. [ABSTRACT FROM AUTHOR]

We tested the effect of main soil characteristics and tree species on earthworm community composition and abundance in reclaimed spoil heaps planted with five different tree species. Earthworm abundance and biomass was highest at alder plantation, followed by the oak plantation. It was positively correlated with the total N content (C:N ratio), which was highest in alder plantation. The correlation was stronger for endogeic earthworms (genus Aporrectodea and Octolasion) than litter-feeders. Soil moisture, measured in top 10 cm, affected only endogeic species. Other soil variables (pH, total P, Ca) didn't have a strong effect on earthworms. The earthworm community composition was similar in alder and oak, with most species occurring at both sites, however in alder forest the epigeic species Dendrobaena octaedra was more common, whilst in oak forest the epigeic earthworms form genus Lumbricus were more abundant (L. rubellus and L. castaneus). The anecic species Aporrectodea longa was more abundant at the alder site, but L. terrestris was more abundant at the Oak site. The alder forest was characteristic by a thick humus layer (10 – 15 cm), which at oak and larch site was thinner (4 – 7 cm) and at pine and spruce stands was absent. Soil macroarthropods were most abundant in alder forest and were strongly correlated with earthworm abundance at each specific site. We conclude that the alder plantations have most palatable litter and lowest C:N ratio, therefore support the highest numbers of soil macrofauna. [ABSTRACT FROM AUTHOR]