Mycobiota of revegetated post‐mining and adjacent unmined sites 10 years after mining decommissioning

Abstract

Although overlooked in post‐mining rehabilitation, soil mycobiota constitute an important fraction of biodiversity, playing pivotal functions in soil that contribute to the revegetation process and soil stability in post‐mining environments. Evaluating the rehabilitation progress requires comparing it, when possible, with a reference site, preferably identical or similar to pre‐mining characteristics. Here, we investigated the mycobiota from a reference site, comparable to pre‐mining characteristics, and a post‐mining revegetated site 10 years after decommissioning and revegetation, during rainy and dry seasons. We combined the metabarcoding approach with functional traits from fungal operational taxonomic units and complemented our results with traditional techniques for arbuscular mycorrhizal fungi (AMF) surveys using spore morphology and mycorrhizal colonization. Our findings demonstrated that the composition of the fungal community exhibited more differences between the two sites studied than the intra‐annual periods assessed, even though the sites were under the same climatic conditions, spatially nearby, and without barriers between them. The mycobiota composition displayed differences between sites from phylum to genus levels. However, the predictive trophic modes (pathotrophs, saprotrophs, and symbionts) were equivalent in the two sites. All roots of plants assessed had AMF colonization, and AMF spore densities were similar. While many fungal taxa were present at both sites, the spatial connectivity between both sites was insufficient for equivalence of fungal community structure and composition. Differences in chemical and physical soil characteristics may have shaped the fungal communities. This study highlights the need to comprehend the fungal community from mining environments, considering concepts of landscape connectivity.