Department of Agricultural Engineering of the E.T.S.I.A. & Soil Ecology and Biotechnology Unit of the Institute of Plant Biotechnology, Technical University of Cartagena, 30203 Cartagena, Spain.
Department of Agricultural Engineering of the E.T.S.I.A. & Soil Ecology and Biotechnology Unit of the Institute of Plant Biotechnology, Technical University of Cartagena, 30203 Cartagena, Spain; Department of Geography, University of Barcelona, 08001 Barcelona, Spain.
Sci Total Environ. 2022 Sep 10;838(Pt 1):155945. doi: 10.1016/j.scitotenv.2022.155945. Epub 2022 May 13.
This study aimed to evaluate whether the improvement in soil conditions induced by the vegetation spontaneously colonizing abandoned metal(loid) mine tailings from semiarid areas is consistent throughout seasons and to identify if the temporal variability of that conditions is of similar magnitude of that of the surrounding forests. Soil climatic (temperature and moisture), chemical (pH, electrical conductivity and water-soluble salts and metal(loid)s) and biological (water-soluble organic carbon and ammonium, microbial biomass carbon, dehydrogenase and β-glucosidase activity, organic matter decomposition and feeding activity of soil dwelling organisms) parameters were seasonally evaluated for one year in bare soils and different vegetated patches within metalliferous mine tailings and surrounding forests in southeast Spain. The results indicated that the improvement in soil conditions (as shown by softening of climatic conditions and lower scores for salinity and water-soluble metals and higher for biological parameters) induced by vegetation colonization was consistent throughout seasons. This amelioration was more evident in the more complex vegetation patches (trees with herbs and shrubs under the canopy), compared to bare soils and simpler soil-plant systems (only trees), and closer to forest soils outside the tailings. Bare soils and, to a lesser extent, vegetation patches solely composed by trees, showed stronger seasonal variability in temperature, moisture content, salinity, and water-soluble metals. In contrast, changes in biological and biological-related parameters were more pronounced in the more complex vegetation patches within mine tailings and surrounding forests due to its greater biological activity. In summary, the results demonstrated that vegetation patches formed by spontaneous colonization act as microsites that modulate seasonal variability in soil conditions and stimulate biological activity. This suggests that tailings vegetation patches might have higher resilience against climate change effects than bare soils. Therefore, they should be preserved as valuable spots in the phytomanagement of metal(loid)s mine tailings from semiarid areas.
本研究旨在评估半干旱地区废弃金属（类）矿山尾矿上自然定居的植被是否能持续改善土壤条件，并确定这些条件的时间变化是否与周围森林相似。在西班牙东南部，对裸露土壤以及金属尾矿和周围森林中的不同植被斑块进行了为期一年的土壤气候（温度和湿度）、化学（pH 值、电导率和水溶性盐和金属（类））和生物（水溶性有机碳和铵、微生物生物量碳、脱氢酶和β-葡萄糖苷酶活性、有机质分解和土壤生物的摄食活动）参数的季节性评估。结果表明，植被定居所引起的土壤条件改善（表现为气候条件软化、盐度和水溶性金属分数降低、生物参数分数升高）在整个季节都是一致的。与裸露土壤和更简单的土壤-植物系统（仅树木）相比，这种改善在更复杂的植被斑块（树冠下的树木和草本植物和灌木）中更为明显，与尾矿外的森林土壤更为接近。裸露土壤和，在较小程度上，仅由树木组成的植被斑块，在温度、水分含量、盐分和水溶性金属方面表现出更强的季节性变化。相比之下，由于生物活性更高，矿山尾矿和周围森林中更复杂的植被斑块内的生物和生物相关参数的变化更为显著。总之，结果表明，由自然定居形成的植被斑块充当微生境，调节土壤条件的季节性变化并刺激生物活性。这表明尾矿植被斑块可能比裸露土壤具有更高的对气候变化影响的恢复力。因此，在半干旱地区金属（类）矿山尾矿的植物管理中，它们应该被视为宝贵的斑块而得到保护。
