Spontaneous growth of native vegetation in abandoned metal(loid) mine tailings can be valuable for phytomanagement restoration projects. This study aimed to assess the degree to which spontaneous plant colonization of abandoned metal(loid) mine tailings from Mediterranean semiarid areas led to functional soil improvement, and to identify, if possible, a critical level indicating that this functionality was moving towards that of the vegetated soils from the surroundings. Vegetation ecological indexes, plant life forms and species functional roles, together with physicochemical and functional soils parameters, were studied in metal(loid) mine tailings abandoned ~40 years ago and surrounding forests in SE Spain. Vegetation patches showed only small differences in physicochemical parameters related to soil abiotic stress conditions (pH, salinity and metals), regardless of the vegetation. However, vegetation patches with greater species diversity and richness and presence of plants with contrasted life forms and functional traits that facilitate the growth of less stress-tolerant species showed an increase of the soil microbial functionality (higher microbial biomass C, β-glucosidase activity, bacterial metabolic activity and functional diversity). Moreover, these vegetation patches showed a functional soil status comparable to that of the forests outside the mine tailings. In this sense, the present study showed the value of preserving these vegetation patches since they may act as nucleation spots favoring positive plant-soil feedbacks that may help to accelerate the functional recovery of these degraded areas. Furthermore, strategies to promote the creation of new vegetation patches including a variety of species with contrasted life forms and functional traits should be considered in phytomanagement restoration projects for abandoned metal(loid) mine tailings.

废弃金属（类）矿尾矿中原生植被的自发生长对于植物管理恢复项目很有价值。本研究旨在评估来自地中海半干旱地区的废弃金属（类）尾矿的自发植物定植导致土壤功能改善的程度，并在可能的情况下确定一个临界水平，表明该功能正朝着来自周围的植被土壤。在大约 40 年前废弃的金属（液体）尾矿和西班牙东南部周围的森林中研究了植被生态指标、植物生命形式和物种功能作用，以及物理化学和功能土壤参数。植被斑块在与土壤非生物胁迫条件（pH、盐度和金属），而与植被无关。然而，具有更大物种多样性和丰富度的植被斑块以及具有对比生命形式和功能特征的植物的存在，这些植物促进了耐逆性较差的物种的生长，显示出土壤微生物功能的增加（更高的微生物生物量 C、β-葡萄糖苷酶活性、细菌代谢活性和功能多样性）。此外，这些植被斑块显示出与尾矿外森林相当的功能性土壤状态。从这个意义上说，本研究显示了保护这些植被斑块的价值，因为它们可能充当有利于植物 - 土壤正反馈的成核点，这可能有助于加速这些退化区域的功能恢复。此外，