Abstract：
A large amount of metal tailings causes many environmental issues. Thus, the techniques for their ecological restoration have garnered extensive attention. However, they are still in the exploratory stage. Biological soil crusts (BSCs) are a coherent layer comprising photoautotrophic organisms, heterotrophic organisms and soil particles. They are crucial in global terrestrial ecosystems and play an equal importance in metal tailings. We summarized the existing knowledge on BSCs growing on metal tailings. The main photosynthetic organisms (cyanobacteria, eukaryotic algae, lichens, and mosses) of BSCs exhibit a high heavy metal(loid) (HM) tolerance. BSCs also have a strong adaptability to other adverse conditions in tailings, such as poor structure, acidification, and infertility. The literature about tailing BSCs has been rapidly increasing, particularly after 2022. The extensive literature confirms that the BSCs distributed on metal tailings, including all major types of metal tailings in different climatic regisions, are common. BSCs perform various ecological functions in tailings, including HM stress reduction, soil structure improvement, soil nutrient increase, biogeochemical cycle enhancement, and microbial community restoration. They interact and accelerate revegetation of tailings (at least in the temperate zone) and soil formation. Restoring tailings by accelerating/inducing BSC formation (e.g., resource augmentation and inoculation) has also attracted attention and achieved small-scale on-site application. However, some knowledge gaps still exist. The potential areas for further research include the relation between BSCs and HMs, large-scale quantification of tailing BSCs, application of emerging biological techniques, controlled laboratory experiments, and other restoration applications.
摘要：
大量的金属尾矿会引起许多环境问题。因此，其生态修复技术受到广泛关注。然而,他们仍处于探索阶段。生物土壤结皮（BSC）是包含光合自养生物的连贯层，异养生物和土壤颗粒。它们在全球陆地生态系统中至关重要，在金属尾矿中同样重要。我们总结了金属尾矿上生长BSC的现有知识。主要的光合生物（蓝细菌，真核藻类,地衣,和苔藓）的BSC表现出高的重金属（类）（HM）耐受性。BSC对尾矿中的其他不利条件也有很强的适应性,比如糟糕的结构，酸化,和不孕症。关于拖尾BSC的文献一直在迅速增加，尤其是2022年之后。大量文献证实，BSC分布在金属尾矿上，包括不同气候区域的所有主要类型的金属尾矿，很常见。BSC在尾矿中发挥各种生态功能，包括HM应力降低，土壤结构改善，土壤养分增加，增强生物地球化学循环，和微生物群落恢复。它们相互作用并加速尾矿的重新植被（至少在温带地区）和土壤形成。通过加速/诱导BSC形成来恢复尾矿(例如，资源扩充和接种）也引起了人们的注意，并实现了小规模的现场应用。然而,一些知识差距仍然存在。进一步研究的潜在领域包括BSC和HMs之间的关系，尾矿BSC的大规模定量，新兴生物技术的应用，受控实验室实验，和其他恢复应用程序。
