The University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, 6009, Australia.
Charles Darwin University, Ellengowan Drive, Casuarina, Northern Territory, 0810, Australia.
Sci Rep. 2020 Feb 19;10(1):2880. doi: 10.1038/s41598-020-59390-9.
Globally, mining activities have been responsible for the contamination of soils, surface water and groundwater. Following mine closure, a key issue is the management of leachate from waste rock accumulated during the lifetime of the mine. At Ranger Uranium Mine in northern Australia, magnesium sulfate (MgSO) leaching from waste rock has been identified as a potentially significant surface and groundwater contaminant which may have adverse affects on catchment biota. The primary objective of this study was to determine the effect of elevated levels of MgSO on two riparian trees; Melaleuca viridiflora and Alphitonia excelsa. We found that tolerance to MgSO was species-specific. M. viridiflora was tolerant to high concentrations of MgSO (15,300 mg l), with foliar concentrations of ions suggesting plants regulate uptake. In contrast, A. excelsa was sensitive to elevated concentrations of MgSO (960 mg l), exhibiting reduced plant vigour and growth. This information improves our understanding of the toxicity of MgSO as a mine contaminant and highlights the need for rehabililitation planning to mitigate impacts on some tree species of this region.
在全球范围内，采矿活动已经导致土壤、地表水和地下水受到污染。矿山关闭后，一个关键问题是处理矿山生命周期中积累的废石淋出液。在澳大利亚北部的兰杰铀矿，从废石中浸出的硫酸镁 (MgSO) 已被确定为一种潜在的重要地表水和地下水污染物，可能对集水区生物群产生不利影响。本研究的主要目的是确定高水平的 MgSO 对两种河岸树木；桃金娘科绿白千层和金合欢属 excelsa 的影响。我们发现，对 MgSO 的耐受性是特定于物种的。M. viridiflora 能耐受高浓度的 MgSO（15300mg/L），叶片中的离子浓度表明植物能调节吸收。相比之下，A. excelsa 对高浓度的 MgSO（960mg/L）敏感，表现出植物活力和生长的降低。这些信息提高了我们对硫酸镁作为矿山污染物的毒性的认识，并强调了恢复规划的必要性，以减轻对该地区一些树种的影响。
