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Soil management practices such as organic matter input can ameliorate soil health, including microbial com munities that are crucial for ecological processes. In this study, the effect of successive application of cattle dung and/or dung beetle on the diversity and ecological guild of topsoil fungal assemblages on a post-coal mining reclaimed site was investigated. Three experimental treatments namely: dung plus dung beetles (dung + beetle), dung only (dung-only), and no dung, no dung beetle (control) was established on 4-m2 subplots on a ≥16-year old post-coal mining reclamation area. Following a 17-month experimental period, topsoil fungal assemblage was determined using next-generation sequencing of fungal ribosomal internally transcribed spacer 2 region. The highest operational taxonomic unit (OTU) richness and Shannon-Wiener diversity were obtained in the dung only treatment while the lowest OTU richness and diversity was obtained in control treatment. Although not statistically significant, a trend towards lower OTU richness in the topsoil was observed with the addition of dung beetle compared to the only dung treatment. In multivariate space, fungal communities were differentiated between dung-only and control, suggesting the influence of dung addition. Overall, dung addition primarily improved topsoil fungal diversity and the abundance of beneficial plant-fungal symbionts important for nutrient mobilisation in the soil, with a trend towards lower diversity observed with dung beetle addition suggesting possible vertical displacement of organic matter and ecologically relevant fungal species to deeper soil depths.

Soil management practices such as organic matter input can ameliorate soil health, including microbial com munities that are crucial for ecological processes. In this study, the effect of successive application of cattle dung and/or dung beetle on the diversity and ecological guild of topsoil fungal assemblages on a post-coal mining reclaimed site was investigated. Three experimental treatments namely: dung plus dung beetles (dung + beetle), dung only (dung-only), and no dung, no dung beetle (control) was established on 4-m2 subplots on a ≥16-year old post-coal mining reclamation area. Following a 17-month experimental period, topsoil fungal assemblage was determined using next-generation sequencing of fungal ribosomal internally transcribed spacer 2 region. The highest operational taxonomic unit (OTU) richness and Shannon-Wiener diversity were obtained in the dung only treatment while the lowest OTU richness and diversity was obtained in control treatment. Although not statistically significant, a trend towards lower OTU richness in the topsoil was observed with the addition of dung beetle compared to the only dung treatment. In multivariate space, fungal communities were differentiated between dung-only and control, suggesting the influence of dung addition. Overall, dung addition primarily improved topsoil fungal diversity and the abundance of beneficial plant-fungal symbionts important for nutrient mobilisation in the soil, with a trend towards lower diversity observed with dung beetle addition suggesting possible vertical displacement of organic matter and ecologically relevant fungal species to deeper soil depths

Anthropogenic disturbances of soil environments predispose loss of soil ecosystem functions, including its habitat support function. In this study, the potential ecosystem support and habitat functions of soils from stockpiles and post-mining reclamation areas (ranging from 3 to 25 years) in two coal mining sites were assessed using Eisenia andrei bioassays. Endpoints such as avoidance response, mortality, relative growth rate and fecundity were determined. By taking into cognisance the ages of the reclamation areas, inference was drawn on the potential restoration of ecosystem support functions over the years since reclamation. Mortality and fecundity of earthworms did not suggest limited support functions of control and test soils. Net avoidance response (AR) indicated significant differences (P < 0.05) among treatments with only the net AR in a 3-year old reclaimed soil >80%. Earthworms generally preferred (P < 0.05) undisturbed (“reference”) soils to OECD and test soils. Furthermore, trends in AR suggested a negative effect (P < 0.05) of anthropogenic disturbance and a general improvement of soil habitat function in older reclaimed areas. Of all endpoints, the avoidance test was the most sensitive, which generally reflected the differences in soil physicochemical properties among test soils. Although high intra-site variations in soil properties suggest lack of strict adherence to best reclamation practices, coal mining soil environments are not ecologically derelict with regards to supporting biocoenosis

Soil microbial communities are suitable soil ecosystem health indicators due to their sensitivity to management practices and role in soil ecosystem processes. Presently, information on structural and functional differentiation of bacterial communities in post-coal mining reclamation soils of South Africa is sparse. Here, bacterial communities in three post-coal mining reclamation soils were investigated using community-level physiological profiling (CLPP), enzyme activities, and next-generation sequencing of 16S rRNA gene. Inferences were drawn in reference to adjacent unmined soils. CLPP-based species diversity and proportionality did not differ significantly (P > 0.05) whereas activities of β-glucosidase, urease and phosphatases were significantly (P < 0.05) influenced by site and soil history (reclaimed vs unmined). Bacterial communities were influenced (PERMANOVA, P < 0.05) by soil history and site differences, with several phylotypes differentially abundant between soils. Contrastingly, predicted functional capabilities of bacterial communities were not different (PERMANOVA, P > 0.05), suggesting redundancy in bacterial community functions between reclamation and unmined soils. Silt content, bulk density, pH, electrical conductivity, Na and Ca significantly influenced soil bacterial communities. Overall, results indicate that bacterial community structure reflects underlying differences between soil ecosystems, and suggest the restoration of bacterial diversity and functions over chronological age in reclamation soils

Until recently, research has focused on Clostridium perfringens in clinical settings without considering environmental isolates. In this study, environmental genomes were used to investigate possible antibiotic resistance and the presence of virulence traits in C. perfringens strains from raw surface water. In silico assembly of three C. perfringens strains, DNA generated almost complete genomes setting their length ranging from 3.4 to 3.6 Mbp with GC content of 28.18%. An average of 3,175 open reading frames was identified, with the majority associated with carbohydrate and protein metabolisms. The genomes harboured several antibiotic resistance genes for glycopeptides, macrolide–lincosamide–streptogramin B, β-lactam, trimethoprim, tetracycline and aminoglycosides and also the presence of several genes encoding for polypeptides and multidrug resistance efflux pumps and 35 virulence genes. Some of these encode for haemolysins, sialidase, hyaluronidase, collagenase, perfringolysin O and phospholipase C. All three genomes contained sequences indicating phage, antibiotic resistance and pathogenic islands integration sites. A genomic comparison of these three strains confirmed high similarity and shared core genes with clinical C. perfringens strains, highlighting their health security risks. This study provides a genomic insight into the potential pathogenicity of C. perfringens present in the environment and emphasises the importance of monitoring this niche in the future