Ecological restoration technologies for ion-adsorption rare earth mines: progress, challenges, and future directions

The large-scale extraction of ion-adsorption rare earth minerals in southern China has led to severe ecological degradation. This degradation is characterized by soil acidification, accumulation of rare earth elements and associated metals, ammonia nitrogen pollution, and oligotrophication, creating combined stresses that hinder restoration. This review systematically summarizes the pollution characteristics and ecological risks of such mining areas, evaluating various single remediation approaches, including physical (soil covering), chemical (lime, phosphates, biochar), and biological (plants, microorganisms, earthworms) methods, as well as their combined technologies. Case studies are analyzed to explore the mechanisms of soil improvement, microbial activity enhancement, and vegetation succession promotion. Special emphasis is placed on the synergistic effects of amendments, plants, and functional microorganisms, and on the pathways for restoring soil fertility and ecosystem functionality under complex pollution. Importantly, this paper highlights the integrative perspective of amendment–plant–microbe interactions, offering novel insights into their coordinated role in mine-site restoration. Furthermore, it discusses future directions including mechanism-oriented research and data-driven dynamic monitoring. This article aims to provide theoretical and practical guidance for selecting and optimizing ecological restoration technologies for ion-type rare earth mining sites.