Search

Heterogeneity of environmental conditions is the crucial factor supporting biodiversity in various habitats, including post-mining sites. The effects of micro-topographic heterogeneity on biodiversity and conservation potential of arthropod communities in post-industrial habitats had not been studied before now. At one of the largest European brown coal spoil heaps, we sampled eight groups of terrestrial arthropods with different life strategies (moths, spiders, ground beetles, ants, orthopteroids, centipedes, millipedes, and woodlice), in successionally young plots (5–18 y), with a heterogeneous wavy surface after heaping, and compared the communities with plots flattened by dozing. A combination of the standardized quantitative sampling, using two different methods, and a paired design of the plot selection enabled a robust analysis. Altogether, we recorded 380 species of the focal arthropods, 15 of them nationally threatened. We revealed the importance of the micro-topographic heterogeneity for the formation of the biodiversity of arthropods in their secondary refuges. The communities with higher biodiversity and conservation value were detected in the plots with heterogeneous surfaces; exceptions were ground beetles and millipedes. The surface flattening, often the first step of technical reclamation projects, thus suppress biodiversity of most terrestrial arthropods during the restoration of post-mining sites. Since the communities of both surface types differed, the proportional presence on both surfaces could be more efficient in supporting the local biodiversity. We suggest reducing the surface dozing for the cases with other concerns only, to achieve a proportional representation of both surface types. Such a combination of different restoration approaches would, thus, efficiently support high biodiversity of groups with various needs.

It has been well established that grazing by fungivorous soil fauna alters competitive relationships among fungal species in simplified microcosmal conditions. To which extent fungal grazers modify the composition of complex fungal communities, however, remains little explored. We therefore addressed the question how microarthropods influence rhizospheric fungal communities and compared the effects of microarthropods among functional guilds of fungi as well as with those of the plant's mycorrhizal type, the key bottom up factor structuring microbial communities in the rhizosphere. In a greenhouse experiment, we cultivated Tripleurospermum inodorum (Asteraceae), a host plant for arbuscular mycorrhizal, and Salix caprea, an ectomycorrhizal host, or both hosts together in soil from a locality where both plants coexist. The defaunated soil contained its native fungal community while microarthropods were either left absent or re-introduced in two experimental treatments, combined in a factorial design with the three host plant treatments. While only plant combination influenced the composition of the fungal communities by the main functional guilds (arbuscular mycorrhiza fungi, ectomycorrhizal fungi, endophytes, plant pathogens and saprotrophs), microarthropod presence had a significant effect on their taxonomic composition. Of the more abundant fungal genera (over 1% community share), microarthropods approximately doubled the relative abundances of five (Cadophora, Exophiala, Truncatella, Meliniomyces, Trichosporon), and significantly increased the absolute abundances of four. In contrast, only one genus (Inocybe) was significantly suppressed by the microarthropods. The genera belonged to all the main functional guilds except arbuscular mycorrhizal fungi. Tolerance to mechanical disturbance, dispersion in soil or response to low intensity grazing are suggested as mechanisms behind the observed stimulation of some fungal taxa.

Geodiversity plays an important role in species establishment during spontaneous succession. At post-mining sites in the Czech Republic in 2003, we established plots in which the surface of the heaped overburden was either kept wave-like or leveled. Based on surveys conducted from 2006 to 2015, leveled plots were increasingly dominated by grasses and herbs (and especially by the grass Calamagrostis epigejos) while the wave-like plots were increasingly dominated by the trees Salix caprea and Betula pendula. In 2015, a detailed survey was conducted of the dominant species. Both S. caprea and B. pendula occurred more often in wave-like plots than in leveled plots; this was particularly true for trees taller than 1 m, which were absent in leveled plots. In wave-like plots, leaf and root biomasses of both woody species were higher on the wave slopes than on the wave depressions. Nitrogen content was higher but content stress indicating proline in leaves of S. caprea was lower in wave-like plots than in leveled plots. In wave-like plots, both woody species occurred mainly on wave slopes but C. epigejos occurred mainly in the depressions. We speculate that trees were more abundant in wave-like plots than in leveled plots because the waves trapped tree seeds and snow and because the soil porosity was greater in wave-like than in leveled plots. Grasses may have preferred the leveled plots because soil porosity was lower and clay content was higher in leveled than in wave-like plots.

To study the effect(s) of soil transplantation on survival and colonization of post-mining spoil heaps by soil fauna, we transplanted blocks of topsoil (3 × 10 × 0.4 m) from a well-developed meadow into the bare post-mining heap in Sokolov coal mining region (Czechia) in 1995. The soil meso and macrofauna were studied in two periods, namely 1995–1997 (initial period) and 20 years later in 2015–16 (follow-up period). We sampled transplanted blocks (Transported), overburden at a 2-m distance from the blocks (Adjacent), and overburden at a 30-m distance from the blocks (Control). The number of mites was highest in the Transported, in the initial period, and at the Control 20 years after- i.e. in the follow-up period. Judging by their higher densities, for Lumbricidae, and most of the miscellaneous macrofauna, Transported was favored in both time periods. The high macroarthropod densities in the Transported position, even after 20 years, and the low microarthropod densities in the Adjacent position together suggest a limited role of transplanted soil blocks in the colonization of the spoil overburden, signifying that soil development of the spoil overburden might be even more critical than the migration barrier.

The majority of studies that investigate plant functional trait effects on ecosystem properties use traits obtained from databases. However, we know little regarding their explanatory power proportionate to that of the semi-quantitative vegetation properties, and much less still is known when considering their temporal changes in a chronosequence. We determined whether soil chemical and biological properties were associated with plant functional traits, observed vegetation properties (“patch type” = bare soil, grassy, woody), and site age (10, 18, 28, and 55 years), at four spontaneously overgrown post-mining locations in the Czech Republic. Abiotic soil properties were expected to be closely related to the site age, while above and below ground macrofauna (epigeic and endogeic, respectively), mesofauna, and microbial biomass were expected to be related to the plant functional traits and patch types. Site age and plant functional traits were more important explanatory factors for most of the chemical, microbial, and macrofaunal soil properties than the patch types. Patch type was the only plant-related factor capable of explaining the mesofauna community variations. Epigeic macrofauna were found to correlate more strongly with the plant functional traits than endogeic macrofauna. The abundance of most fauna correlated positively with an increase in plant cover and litter input and was significantly higher in vegetated patches and old sites.

Woodchip-based denitrification bioreactors are widely used for treatment of high loads of nitrate pollution in agricultural run-off water. A concern raised recently, as a consequence of various organic fillings being experimented with, is whether the positive effect given by nitrate reduction could override the negative effects of such bioreactors, mainly caused by degradation of wood and the production of potentially harmful conditions for aquatic ecosystems. This paper presents the results of the experimental testing of two different filling materials: birch (BWCH) and spruce (SWCH) woodchip, and their mixture with washed gravel (WG) in volumetric ratio 10:1. We have focused on the leaching of organic carbon and phenols, and its impact on selected aquatic organisms, as well as on their denitrification efficiency and NO3− load removal rate (LRT). The results show that TOC, DOC and FNI (phenolic index) leaching is higher for the pure woodchip materials and is closely correlated with the growth inhibition of tested organisms (Vibrio fischeri, Daphnia magna, Desmodesmus subspicatus, Lemna minor). The highest denitrification efficiency and the highest load removal rates were recorded in mixed filling material (96% and 1.4 mg NO3−·dm3·d−1 for WG:BWCH; 85% and 1.2 mg NO3−·dm3·d−1 for WG:SWCH). Denitrification bioreactors with mixed woodchip filling material present a promising, cheap, and extensive technology for the treatment of agricultural field run-offs.

Although plant-soil interactions are increasingly recognized as an important factor in ecosystem restoration, their effects on community assembly during de novo ecosystem establishment are largely unknown. In a heathland restoration trial after topsoil removal we introduced either only aboveground heathland species with fresh herbage or both above- and belowground heathland species with sods to facilitate community assembly. Sod inoculation increased resemblance of the microbial community to the reference system, with a higher fungal and lower bacterial proportion to the community structure. Also densities of bacteriophagous and phytophagous nematodes, Acari and Collembola increased after sod inoculation. The cover of heathland plant species increased by 49% after sod inoculation. The introduction of solely aboveground heathland species increased the cover of these species by only 13%, and did not affect soil community assembly. Additionally, the increase in cover of heathland species over time was inversely correlated to the cover of mesotrophic grassland species. Inverse correlations were also observed between changes in fungal and bacterial abundances. Simultaneous introduction of key species of both above- and below-ground communities had a critical effect on the establishment of both communities, providing a potential shortcut for successful restoration of target ecosystems on disturbed soils.

The absence of environmentally sensitive soil management systems can be considered as one of the major risks to sustainability of agricultural soils in Iran. Tillage is the most critical operation in soil management designed to achieve high crop yield, but it can adversely affect the soil fauna in several ways. In the present study, assessment of soil fauna was carried out in Western Iran in 2008 and 2009 in soil subjected to conventional (CT), minimum (MT) and no (NT)-tillage systems and amended with three levels of cattle manure (CM). Earthworm, mite, springtail and nematode populations were measured as indicators of macro, meso and micro fauna groups, respectively. Soil moisture and bulk density were also determined. Generally, low populations of soil fauna were observed consistent with expectations under similar conditions for this region. Earthworm populations were low and had a patchy distribution. Tillage and CM were found to have no effects on soil mites in both years. Soil springtails were reduced by soil tillage, indicating their sensivity to soil disturbance induced by tillage. In 2008, the nematode population was greater with application of 40 ton ha−1 CM applications (113 N.100 g soil−1). Soil tillage-induced disturbance reduced nematode population in 2009 (214 N.100 g soil−1 at CT). Minimum seedbed preparation besides less soil disturbance makes MT a proper tillage system for Zea mays cultivation. Cattle manure application increased Z. mays’ biomass, but according to our results its annual application is not recommended. There were no changes in BD in both years. We conclude that in short-term studies, soil nematode populations are suitable biological indices (under similar soil and climatic conditions) for the ecological comparison of agricultural management systems in Iran.