Effect of dung and dung beetle application on topsoil fungal assemblage of a post-coal mining reclamation land: Towards soil health improvement

Abstract

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.