Occurrence of arbuscular mycorrhizal fungi in mining-impacted sites and their contribution to ecological restoration: Mechanisms and applications

Mining activities generally decrease topsoil and vegetation, reduce soil biodiversity, and yield extremely harsh environmental conditions, which in turn limit natural revegetation and soil restoration. Ecological restoration of mining sites using beneficial microorganisms such as arbuscular mycorrhizal (AM) fungi (AMF) is considered necessary and useful. In this article, several aspects of AMF-assisted ecological restoration of mining-impacted sites were reviewed. First, the data collected from 98 previous studies show that more than 80% of surveyed plants growing on mining sites are colonized by AMF, and a great number of AMF species and a large AMF diversity exist in various mining-impacted sites. Second, AMF can promote ecological restoration of mining-impacted sites through various possible mechanisms at different scales, such as improving mineral acquisition and tolerance of host plants, contributing to soil structure and quality, and helping maintain ecosystem stability and functioning. Third, a total of 101 studies on AMF and mine restoration, including 22 field and 79 laboratory experiments, were summarized, most of which (95%) confirm that AMF exhibit significant positive effects, such as increased plant survival, enhanced growth and nutrition, improved soil structure and quality, and greater plant re-establishment. Finally, the future prospects regarding enhancing AMF-assisted restoration were discussed.