Search

The estimation of Soil Organic Carbon (SOC), Total Nitrogen (TN), and Soil Water Storage (SWS) is crucial in comprehending ecosystem services and environmental sustainability. It plays a crucial role in guiding sustainable restoration strategies and supporting the long-term health of post-mining sites. Remote sensing technology provides valuable tools for modelling and mapping soil properties in reclaimed post-mining sites efficiently and cost-effectively. This study aimed to utilize remote sensing data to estimate SOC, TN, and SWS in a reclaimed post-mining site. Field data was collected from 130 research plots to obtain reference data for SOC, TN, and SWS from the Sonica hard coal post-mine spoil heap. Remote sensing data were: airborne laser scanning (ALS) point clouds and Planets cope satellite imageries. Generalized Additive Models (GAM) were used to develop predictive models. Wall-to-wall predictions of analyzed variables were performed. The results identified topographic and remote sensing indicators that significantly influence SOC, TN, and SWS. Digital Terrain Model (DTM), aspect, and blue spectral band are variables that explain SOC storage, with a significant influence of DTM, ranging from −8 to 18 Mg ha−1. TN was explained by DTM, Canopy Height Model (CHM), blue and Near Infrared (NIR) spectral bands, and Normalized Difference Vegetation Index (NDVI), mainly influenced by NIR and NDVI, ranging from −1.1 to 0.8 and −0.9 to 1.4 Mg ha−1, respectively. The values of Topographic Wetness Index (TWI), aspect, CHM, blue and NIR spectral bands explained SWS, highlighting their importance in assessing soil water dynamics in post-mining landscapes, with TWI and CHM being particularly influential, ranging from −2 to 5.1 and −6 to 2 mm, respectively. However, caution is advised when predicting SOC and TN using remote sensing in post-mining sites due to geogenic carbon considerations.

Aiming at the deformation control problem of the tunnel entrance crossing the spoil heap at the Xialao junction, this paper adopts the micropile combined with the coupling beams method to treat the spoiled layers. The results show that the excavation of the tunnel after the construction of the micropile and coupling beam will cause vertical deformation of the tunnel and the slope surface. The main reason is that the soil layer structure is loose, and the tunnel excavation causes the whole displacement of the loose body. In addition, the buried depth of the tunnel is shallow, so it cannot form an effective soil arch. The stability process after the construction of the micropile method is the process of stress redistribution, and the rock and soil are gradually compressed and compacted. That is, the construction by the micropile method changes the surrounding rock level of the tunnel and reduces the height of the soil arch. Therefore, it is suggested that the tunnel excavation should be carried out when the micropile is constructed after the soil layers are consolidated completely. The micropile method treats the loose spoiled soil at the tunnel entrance, which saves 73% of the total cost compared with the scheme of directly digging out the accumulation, and the economic benefit is very obvious. [ABSTRACT FROM AUTHOR]

Many studies examining plant and terrestrial invertebrate communities have revealed the high conservation potential of spoil heaps. On the other hand, the freshwater communities inhabiting post‐mining ponds within these human‐made habitats are almost unexplored. We focused on aquatic macroinvertebrate, zooplankton, and phytoplankton communities in the littoral zones of 24 ponds situated on spoil heaps created after lignite mining in the Czech Republic. We compared environmental factors, taxa richness, and conservation value (number of threatened aquatic macroinvertebrate species) in the ponds, based on the type of restoration approach applied, that is, technical reclamation, spontaneous succession, and their combination (semi‐spontaneous succession). While macroinvertebrate and zooplankton taxa richness did not differ significantly between the three types of pond, the phytoplankton community did, with the highest taxa richness recorded in technically established ponds. From a nature conservation point of view, the spontaneously developed ponds hosted almost twice as many threatened macroinvertebrates as the other ponds; nevertheless, even the technically constructed ponds hosted considerable populations of rare species, e.g. the regionally extinct beetle Limnebius nitidus (Marsham, 1802), and contributed to the overall conservation value of the spoil heaps. The most significant driver structuring post‐mining pond freshwater communities was the percentage of vegetation in the littoral zone. [ABSTRACT FROM AUTHOR]

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]

Most ground filtering algorithms are primarily designed for airborne LiDAR point cloud processing and their successful use in identifying ground points from photogrammetric point clouds remains questionable. We compared six ground filtering algorithms implemented in Metashape, ArcGIS, CloudCompare, LAStools, and PDAL. We used UAV photogrammetry-based (acquired under leaf-off conditions) and airborne LiDAR (leaf-on) point clouds of the same area to: (i) compare accuracy of generated DTMs; (ii) evaluate the effect of vegetation density and terrain slope on filtering accuracy; and (iii) assess which algorithm parameters have the greatest effect on the filtering accuracy. Our results show that the performance of filtering algorithms was affected by the point cloud type, terrain slope and vegetation cover. The results were generally better for LiDAR (RMSE 0.13–0.19 m) than for photogrammetric (RMSE 0.19–0.23 m) point clouds. The behavior in varying vegetation and terrain conditions was consistent for LiDAR point clouds. However, when applied on photogrammetric point clouds, the algorithms’ behavior was inconsistent, especially in areas of steep slope (except for the Progressive Triangulated Irregular Network in LAStools). Parameters related to the selection of the initial minimum elevation ground points were the most influential in all algorithms and point clouds.

Functional traits are linked to ecosystem processes and services and therefore relevant in recovery assessment. However, traits of bryophytes and lichens, important components of many ecosystems, have received less attention than those of vascular plants. We explored the use of functional traits of multiple important organism groups in recovery assessment. We combined data on traits and species composition for vascular plants, bryophytes, and lichens from four alpine spoil heaps and their undisturbed surroundings in western Norway, collected at three time‐points spanning more than two decades. We studied changes in community‐weighted mean (CWM) trait values and distribution of trait‐category optima over time. We analyzed temporal variation in joint functional trait composition using the ordination regression‐based approach (ORBA) to predict time to recovery. We observed functional shifts along the successional gradient for all organism groups, e.g. from wind‐dispersed propagules shortly after disturbance to vegetative reproduction at later successional stages. Over time, the similarity between dispersal‐related traits of vascular plants and bryophytes on the spoil heaps and in their surroundings increased, indicating that propagule influx is important in alpine restoration. The joint functional trait composition of all spoil heaps converged towards that of their surroundings: one spoil heap had recovered 34 years after construction, while the predicted time to recovery for the other three was 59–74 years. Our results indicate that inclusion of multiple organism groups improves trait‐based recovery assessments and time‐to‐recovery predictions. Further development of trait databases is essential for future use of joint functional trait composition in recovery assessment. [ABSTRACT FROM AUTHOR]

Inland water bodies are globally threatened by environmental degradation and climate change. On the other hand, new water bodies can be designed during landscape restoration (e.g. after coal mining). Effective management of new water resources requires continuous monitoring; in situ surveys are, however, extremely time-demanding. Remote sensing has been widely used for identifying water bodies. However, the use of optical imagery is constrained by accuracy problems related to the difficulty in distinguishing water features from other surfaces with low albedo, such as tree shadows. This is especially true when mapping water bodies of different sizes. To address these problems, we evaluated the potential of integrating hyperspectral data with LiDAR (hereinafter “integrative approach”). The study area consisted of several spoil heaps containing heterogeneous water bodies with a high variability of shape and size. We utilized object-based classification (Support Vector Machine) based on: (i) hyperspectral data; (ii) LiDAR variables; (iii) integration of both datasets. Besides, we classified hyperspectral data using pixel-based approaches (K-mean, spectral angle mapper). Individual approaches (hyperspectral data, LiDAR data and integrative approach) resulted in 2–22.4 % underestimation of the water surface area (i.e, omission error) and 0.4–1.5 % overestimation (i.e., commission error).The integrative approach yielded an improved discrimination of open water surface compared to other approaches (omission error of 2 % and commission error of 0.4 %). We also evaluated the success of detecting individual ponds; the integrative approach was the only one capable of detecting the water bodies with both omission and commission errors below 10 %. Finally, the assessment of misclassification reasons showed a successful elimination of shadows in the integrative approach. Our findings demonstrate that the integration of hyperspectral and LiDAR data can greatly improve the identification of small water bodies and can be applied in practice to support mapping of restoration process.

Most ground filtering algorithms are primarily designed for airborne LiDAR point cloud processing and their successful use in identifying ground points from photogrammetric point clouds remains questionable. We compared six ground filtering algorithms implemented in Metashape, ArcGIS, CloudCompare, LAStools, and PDAL. We used UAV photogrammetry-based (acquired under leaf-off conditions) and airborne LiDAR (leaf-on) point clouds of the same area to: (i) compare accuracy of generated DTMs; (ii) evaluate the effect of vegetation density and terrain slope on filtering accuracy; and (iii) assess which algorithm parameters have the greatest effect on the filtering accuracy. Our results show that the performance of filtering algorithms was affected by the point cloud type, terrain slope and vegetation cover. The results were generally better for LiDAR (RMSE 0.13–0.19 m) than for photogrammetric (RMSE 0.19–0.23 m) point clouds. The behavior in varying vegetation and terrain conditions was consistent for LiDAR point clouds. However, when applied on photogrammetric point clouds, the algorithms' behavior was inconsistent, especially in areas of steep slope (except for the Progressive Triangulated Irregular Network in LAStools). Parameters related to the selection of the initial minimum elevation ground points were the most influential in all algorithms and point clouds. [ABSTRACT FROM AUTHOR]

Spoil heaps laid from the infrastructure building sites or the mining sites are confoundedly prone to accelerated soil erosion and inducing debris flows on extreme rainfall occasion, thus threatening water quality and personal safety. In present study, the roughness and drainage network evolution of the loess spoil heap (a 33° slope gradient) were investigated via indoor simulation experiment under three rainfall intensities (60, 90, and 120 mm/h). A detailed scan of the slope using laser scanner, topographic analysis based on ArcGIS software, and statistical analyses were the main methods utilized in the study. The results showed that surface roughness increased with cumulative rainfall. For three rainfall intensity treatments, the proneness of shallow landslide under 90 mm/h intensity resulted in the largest roughness. The drainage density and stream frequency of the spoil heap slope both decreased with cumulative rainfall and negatively correlated with surface roughness, which indicated the convergence of the drainage network. Meanwhile, the individual flow paths presented an increasing sinuosity and a decreasing gradient with cumulative rainfall. However, drainage network features varied in a less marked degree during different rainfall intensities, showing comparable fractal dimensions of 1.350–1.454, 1.305–1.459, and 1.292–1.455 for the three rainfall intensities. Evaluating the response of four hydrodynamic characteristics of runoff to the drainage network evolution, stream power was found to be most sensitive. The linearity of the relationships between stream power and drainage density and that between stream sinuosity and gradient were estimated to have R2 between 0.961 and 0.979.

• Post-mining brooks represent habitats similar to endangered natural spring brooks. • Post-mining brooks harboured spring specialists and red-listed species. • Species compositions of post-mining and natural brooks were distinct. • Differences were caused mainly by extreme environment related to post-mining brooks. Surface coal mining severely affects natural ecosystems, though it might also result in an establishment of biologically unique anthropogenic habitats. We studied spontaneously created post-mining calcareous brooks located at the brown coal spoil heap in the Sokolov coal basin (Czechia). Despite their extreme water conditions, linked most to the ionic mixture of dissolved ions (mainly SO 4 2−, Ca2+ and Mg2+), and ferric hydroxide precipitations, we recorded unexpectedly species-rich assemblages there (150 species), including several spring fen specialists (31 species) and eight threatened red-listed species. Macroinvertebrate assemblages of post-mining calcareous habitats were compared with those reported from natural brooks draining Western Carpathians calcareous spring fens. The species richness found in the post-mining calcareous brooks was significantly lower than that of the natural calcareous spring brooks. Although we found 29% of species recorded in the two study systems in common (i.e. 80 species), species composition of their assemblages was systematically distinct. This suggests a possible role of environmental filtering in the post-mining brooks and/or dispersal limitation of some species typical for natural calcareous spring brooks (e.g. Trichodrilus strandi , Bythinella austriaca). In contrast, many macroinvertebrates, particularly those of high dispersal capacities (i.e. Odonata, Coleoptera and Diptera), can recognize post-mining calcareous brooks as surrogate habitats for the natural calcareous spring brooks. [ABSTRACT FROM AUTHOR]

No in‐depth studies covering litter decomposition were previously conducted on afforested postmining sites despite the importance of litter decomposition on soil formation, especially in degraded areas. We aimed to compare leaf litter decomposition rates of 14 tree species growing in mixed stands on a postmining spoil heap, and to compare their decay rates with those obtained in pure stands of tree species that are very often planted in postmining areas. The study was conducted on the Bełchatów Lignite Mine spoil heap, central Poland. We studied litter decomposition rates over 5 years using the litterbag method. Leaf litter decomposition rates (k constants; yr−1) after 5 years of the experiment were arranged from highest to lowest as follows: Prunus serotina (1.04), Alnus glutinosa (0.86), Fraxinus excelsior (0.81), Ulmus laevis (0.73), Acer pseudoplatanus (0.68), Populus tremula (0.63), Populus × canadensis (0.59), Betula pendula (0.54), Populus nigra 'Italica' (0.38), Quercus rubra (0.36), Pinus sylvestris (0.34), Robinia pseudoacacia (0.34), Fagus sylvatica (0.25), and Quercus robur (0.22). Decomposition rates increased with Mg, Ca, and summed Mg + Ca + P + K contents in freshly fallen leaves (%). All species‐specific decomposition rates were higher in mixed than in Scots pine stands. Half of them were also higher than in pure stands of other tree species. Our results indicate that tree species composition could significantly affect the physiochemical properties of upper soil horizons on reclaimed areas. Based on these findings, we recommend planting high share of not only A. pseudoplatanus, A. glutinosa, and U. laevis but also F. sylvatica and Q. robur in stands on postmining spoil heaps, because mixed stands can accelerate soil development more than pure stands. [ABSTRACT FROM AUTHOR]

The paper presents the results of a study of epigenetic changes in technogenic-redeposited coal-bearing rocks of Irkutsk and Kuznetsk coal basin spoil heaps (Russia). Hydrocarbon products formed under high-temperature and low-temperature pyrolysis of coal-bearing rocks were studied by using a chromatography-mass spectrometer GCMS-QP2010NC Plus (made by Shimadzu Company). The average temperature of low-temperature natural pyrolysis does not exceed 120 °C, and its average speed is approximately 2 m/year. In this case, three pyrolysis zones gradually built metamorphic rock mass (from bottom to top) are clearly established: heating (focal) activated and enriched. The average temperature of high-temperature pyrolysis reaches 850 °C, and its average speed is approximately 20 m/year. Unlike low-temperature pyrolysis, high-temperature pyrolysis is accompanied by the presence of two major zones (from bottom to top): pyrogenic (focal) and enriched (coke). The chemical composition of the enriched pyrolysis zone was studied in detail. It has been established that hydrocarbon compounds in samples of the pyrolysis zone are presented by six classes: asphaltic-resinous substances; polycyclic aromatic hydrocarbons, heterocyclic compounds, organic sulphur compounds; pyrolytic hydrocarbon and heavy hydrocarbon residue. Quantitative content of hydrocarbon compounds in the analyzed samples varies from 0.35% to 41.88%.

In recent years, there has been a major development in the field of Unmanned Aerial Vehicles (UAVs) as well as a significant increase in the use of aerial photogrammetry, which is an affordable alternative to using LiDAR. However, the nature of the data obtained from photogrammetry differs from LiDAR data. Photogrammetry using the Structure from Motion (SfM) method is however computationally complicated, and results can be affected by many influences. In this paper, data from two UAVs were compared. The first one is a commercial eBee system produced by SenseFly equipped with a Sony Cyber-shot DCS-WX220 camera. The other is a home assembled solution consisting of EasyStar II motorised glider and 3DR Pixhawk B autopilot equipped with Nikon Coolpix A camera. The area of spoil heap was measured by both systems in the leaf-off period. Both systems were set up identically for data acquisition (overlapping, resolution), which made a comparison of the output quality possible. The ground control points (GCPs) were placed in the study area and their position determined by GNSS (RTK method). A traditional approach for point clouds accuracy validation is their comparison with data of greater accuracy. Unfortunately, the photogrammetry is often validated using GNSS points, the position of which is determined under different conditions than GCPs (different daytime, number, and visibility of satellites, etc.). The magnitude of photogrammetry errors is theoretically the same as that of GNSS. Therefore, in this study, we suggest a novel approach that can be used to compare the accuracy of UAV point clouds without the need for additional validation data (for example, GNSS survey). To exemplify this approach, we used data gathered by two UAV systems (eBee and Easy Star II). Particularly, we statistically estimated the accuracy of the UAV point clouds; used two approaches to estimate standard deviations (one of them using estimated dependencies between data); and investigated the influence of the vegetation cover. To determine the systematic and random errors of the UAV systems data, three areas were selected, each with a typical example of vegetation on the spoil heap (forest, grass, bush). A comparison of the individual data in a grassy area suggests that the accuracy of the differences is about 0.03 m, which corresponds to the actual pixel size. Average shift (systematic error) ranged from 0.01 m to 0.08 m. In the forest terrain, the accuracy of data differences is about 0.04 m, which is slightly worse than in the grassy area. Bushy terrain data achieves precision values between a grassy area and a forest area. [ABSTRACT FROM AUTHOR]

Tree species effects in afforestation of post-industrial lands have important impacts on biodiversity of restored sites. We aimed to assess tree species effects on bryophytes in a novel ecosystem – a reclaimed lignite mine spoil heap. We investigated bryophyte species pools in tree stands of six species: Alnus glutinosa , Betula pendula , Pinus sylvestris , Quercus robur , Q. rubra and Robinia pseudoacacia in two substratum groups: epigeic and epiphytic species. We assessed beta-diversity among tree stand types and bryophyte guilds. We also analyzed impacts of light availability, pH and C/N ratios of bark and soil, annual litterfall and bark water capacity of the main tree species, on bryophyte species pools among tree stands and species groups, using canonical correspondence analysis. Our study revealed tree species effects on bryophyte species richness, beta-diversity and composition. Main mechanisms connected with tree species effects were light availability and substratum C/N ratio, as well as substratum pH and bark water capacity. We confirmed that tree species traits connected with C/N ratios and light availability affect bryophyte species composition. Guilds of bryophytes responded differently to tree species effects on ecosystem properties and their turnover differed between tree stands. Influence of the factors studied on species pools was similar to those reported from mature woodlands. Presence of many woodland specific bryophytes has shown restoration success ca. 30 years after afforestation of post-industrial land. Different tree species provided different habitats for bryophytes, and therefore decisions regarding what tree species to plant affect restoration success and the future bryophyte species pool. [ABSTRACT FROM AUTHOR]

Tree litter decomposition on disturbed post-mining sites has been mainly studied within successional gradients, whereas almost no results were shown from afforested spoil heaps. Litterfall and its decomposition rate are considered the most important ecological processes for soil restoration during stand development on such initial forest habitats. These processes allow development of a functional ecosystem and productive forest stands. Moreover, the pedogenesis process on such “soilless”’ habitats can be significantly improved and accelerated by tree species selection during afforestation. The main aim of the study was to determine litter decomposition rates of nine tree species used for afforestation of a lignite mine spoil heap. We assumed that leaf litter decomposition rates would differ among tree species studied and that the site conditions would significantly influence this process. Our study was conducted on the spoil heap of the lignite open cast mine in Bełchatów, central Poland. We studied leaf litter decomposition of Alnus glutinosa , Betula pendula , Pinus sylvestris , Quercus robur , Q. rubra and Robinia pseudoacacia in pure stands of these species (home stands), and litter decomposition of Acer pseudoplatanus , A. glutinosa , Fagus sylvatica , Prunus serotina , Q. rubra , and R. pseudoacacia in Scots pine stands. We used the litterbag method. The experiments lasted for three years and the samples were collected every three months. Leaf litter decomposition calculated for home stands after three years of decomposition was 94.4% of the initial leaf mass for A. glutinosa , 70.9% for R. pseudoacacia , 70.1% for P. sylvestris , 68.3% for B. pendula , 66.9% for Q. rubra and 61.5% for Q. robur . In Scots pine stands, after three years of the experiment, 92.3% of the initial leaf mass decomposed for P. serotina , 85.7% for A. glutinosa , 83.5% for A. pseudoplatanus , 65.2% for R. pseudoacacia , 50.9% for Q. rubra and 40.1% for F. sylvatica . A. glutinosa , R. pseudoacacia and Q. rubra leaves decomposed significantly faster in home stands than in Scots pine stands. Site aspect significantly influenced litter decomposition of the species studied, with higher rates mostly on the western slope. Our study revealed that the decision on tree species used for afforestation might shorten the period needed for soil restoration and achievement of sustainability of novel ecosystems. Proper selection of main and admixture tree species for afforestation of the post-mining sites might reduce the renewal period of the soilless and newly created habitats, which may provide noticeable ecological and economical effects during stand management. [ABSTRACT FROM AUTHOR]

Many studies have investigated the vegetation and terrestrial fauna of post-mining spoil heaps, but little is known about aquatic macroinvertebrates in these areas, particularly at spring-fed habitats. We studied nine seepages (i.e. spring-fed habitats) located at two neighbouring spoil heaps in the Sokolov brown-coal basin (Czech Republic), characterised by basic water pH, calcium carbonate precipitation, high heavy metal and sulphate concentrations. Along with these nine artificial calcareous seepages, we also sampled macroinvertebrates at 15 natural and well-preserved calcareous spring fens to compare species richness and assemblage similarity between these two systems. We also categorised recorded species as spring specialists or generalists (i.e. matrix-derived species) to compare their importance for the similarity in diversity of these two habitat types. Our study revealed that post-mining calcareous seepages harboured unusually taxa-rich macroinvertebrate assemblages (158 taxa), despite their harsh conditions related to extreme water chemistry. Diptera, with 85 taxa, were the most diverse group, reaching taxon richness comparable with dipteran assemblages in natural calcareous spring fens. According to Sørensen pair-wise dissimilarity, dipteran assemblages of post-mining and natural sites were more similar in the composition of spring specialists than that of generalists, showing a strict relationship between specialist assemblages and specific environmental conditions of post-mining and natural sites. In addition, dipterans inhabiting post-mining seepages were demonstrated not to be limited by their extreme water chemistry, but they seemed to be associated with specific substratum properties, creating a mosaic of various microhabitats. We can therefore conclude that calcareous post-mining seepages have great potential to offer valuable analogues of natural habitats and may create biodiversity refuges for a high number of aquatic invertebrates, including spring habitat specialists and nationally threatened species. Thus, post-mining seepages seem to have similar or even higher conservation potential to more complex and larger post-mining freshwater habitats, such as post-mining streams and mine subsidence pools. [ABSTRACT FROM AUTHOR]

Research Highlights: Direct comparison of leaf litter decomposition rates between harsh soil conditions of degraded lands and adjacent “closer to natural„ forest areas has not been done before. Background and Objectives: We aimed to fill this knowledge gap by determining the differences in amounts of carbon and nitrogen released by species-specific litter depending on decomposition rates in various stand and habitat conditions, which enables selection of the most ecologically and economically appropriate (for fast soil organic layer development) tree species for afforestation of reclaimed lands. Materials and Methods: The study was conducted on the external spoil heap of the “Bełchatów„ lignite mine (Central Poland) and adjacent forests. In December 2013, we established a litterbag experiment beneath the canopies of birch and pine stands. We used litter of Alnus glutinosa (Gaertn.), Betula pendula (Roth), Pinus sylvestris (L.), and Quercus robur (L.) collected ex situ, which we installed (after oven-drying) beneath the canopies of eight stands. The experiment lasted for three years (with sampling of three-month intervals). Results: Harsh soil conditions of degraded lands are unfavorable for litter mineralization. It was found that 23%–74% of decomposed materials were mineralized in spoil heap stands, whereas in forest stands these amounts ranged from 35%–83%. Litter of Q. robur in birch stands on the spoil heap is predicted to take 12 years longer for total decomposition than in forest stands of the same species. This hinders organic carbon turnover and could result in elongation of the time for full biological and economic reclamation of degraded lands. On the other hand, decomposition of relatively fast decomposable litter (A. glutinosa and B. pendula) in pine stands on the spoil heap was faster than in pine stands in forest sites (17% and 13% faster, respectively). We did not observe this trend for decomposition of more recalcitrant litter types of P. sylvestris and Q. robur. Conclusions: The results show the value of selective choice of tree species for afforestation of post-mining areas to accelerate the development of technogenic soil substrates. We recommend introducing all tree species studied in the cluster form of admixtures as all of them could bring some profits in ecological and economical reclamation.

The main objective of reclamation activities is to accelerate the restoration of post-industrial areas. However current ecological studies that compare reclaimed and non-reclaimed habitats evaluate these areas mainly by species richness and conservation potential. We thus tested which environmental characteristics of the spoil heap determine the structure of the beetle communities and their successional rate. During the years 1993–2007, we sampled epigeic beetles on reclaimed and non-reclaimed parts of a spoil heap in the city of Ostrava, Czech Republic. For comparison, we used multivariate methods and functional diversity indices. Our ordination models revealed that the beetle communities on the non-reclaimed part of the spoil heap were determined by forest cover and time; in contrast, the communities on the reclaimed habitat were determined by herb cover and bare ground cover. Compositional heterogeneity was significantly higher on the non-reclaimed part of the spoil heap. A comparison of the functional diversity indices showed significantly higher functional richness and evenness on the spontaneously restored part of the spoil heap. Our results provide evidence that technical reclamation is a significant disturbance that slows down the successional rate of beetle communities and negatively influences their structure. We thus recommend that at least some parts of the areas needing to be reclaimed be allowed to undergo spontaneous succession during reclamation. The areas undergoing spontaneous succession would become refuges for particular species while also supporting the heterogeneity of the habitat. [ABSTRACT FROM AUTHOR]