Response of soil geochemical properties and microbial communities to long-term storage in two mine operations in the Interior of British Columbia: Implications for restoration practices

Mining activities are often severely disruptive to the landscape and a major barrier to reclamation after mining is lack of quality topsoil. This project addresses knowledge gaps in the industry by exploring the compositional nature of topsoil stockpiles and their ability to facilitate post-mining revegetation after long-term storage. To do this, we conducted an extensive profile characterization of two topsoil stockpiles in the interior of British Columbia, where soil geochemical properties and microbial communities with high-throughput sequencing were investigated. Both stockpiles show depleted soil quality and significant changes compared to reference soils. Importantly, there were declines in microbial diversity, major shifts in community structure, and a reduction in soil nutrients with increasing stockpile depths in one of the stockpiles. These results highlight the important influence of topsoil-stockpile height on geochemical properties and microbial communities in the soil, which ultimately influences the success of restoration. This research can help industry to optimize restoration and expediate recovery in their mine-closure practices and provides insights into the general structure of the microbiome existing across a gradient in severely disturbed mining soils.mine reclamationsoil microbial ecologyecosystem restorationsoil response to disturbancehigh-throughput sequencin