Centre for Mine Site Restoration, Department of Environment and Agriculture, Curtin University, GPO Box U1987, Bentley, WA 6102, Perth, Australia; School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Perth, Australia; Kings Park and Botanic Garden, Kings Park, WA 6005, Perth, Australia.
School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Perth, Australia.
Sci Total Environ. 2017 Dec 31;607-608:168-175. doi: 10.1016/j.scitotenv.2017.07.005. Epub 2017 Jul 27.
Tailings are artificial soil-forming substrates that have not been created by the natural processes of soil formation and weathering. The extreme pH environment and corresponding low availability of some macro- and micronutrients in alkaline tailings, coupled with hostile physical and geochemical conditions, present a challenging environment to native biota. Some significant nutritional constraints to ecosystem reconstruction on alkaline tailings include i) predominant or complete absence of combined nitrogen (N) and poor soil N retention; ii) the limited bioavailability of some micronutrients at high soil pH (e.g., Mn, Fe, Zn and Cu); and iii) potentially toxic levels of biologically available soil phosphorus (P) for P-sensitive plants. The short regulatory time frames (years) for mine closure on tailings landforms are at odds with the long time required for natural pedogenic processes to ameliorate these factors (thousands of years). However, there are similarities between the chemical composition and nutrient status of alkaline tailings and the poorly-developed, very young calcareous soils of biodiverse regions such as south-western Australia. We propose that basic knowledge of chronosequences that start with calcareous soils may provide an informative model for understanding the pedogenic processes required to accelerate soil formation on tailings. Development of a functional, stable root zone is crucial to successful ecological restoration on tailings, and three major processes should be facilitated as early as possible during processing or in the early stages of restoration to accelerate soil development on alkaline tailings: i) acidification of the upper tailings profile; ii) establishment of appropriate and resilient microbial communities; and iii) the early development of appropriate pioneer vegetation. Achieving successful ecological restoration outcomes on tailings landforms is likely one of the greatest challenges faced by restoration ecologists and the mining industry, and successful restoration on alkaline tailings likely depends upon careful management of substrate chemical conditions by targeted amendments.
尾矿是一种人工土壤形成基质，不是通过土壤形成和风化的自然过程产生的。在碱性尾矿中，极端的 pH 环境和相应的一些大量和微量元素的低可用性，加上恶劣的物理和地球化学条件，对本地生物群构成了挑战。在碱性尾矿上进行生态系统重建的一些重要营养限制包括：i）主要或完全缺乏结合氮（N）和土壤 N 保留能力差；ii）在高土壤 pH 下一些微量元素的生物利用度有限（例如，Mn、Fe、Zn 和 Cu）；iii）对 P 敏感植物而言，土壤中有效磷（P）的潜在毒性水平。尾矿地貌上矿山关闭的监管时间框架很短（几年），与自然成土过程改善这些因素所需的时间（数千年）不匹配。然而，碱性尾矿的化学成分和养分状况与生物多样性丰富的地区（如澳大利亚西南部）发育不良、非常年轻的钙质土壤相似。我们提出，从钙质土壤开始的年代序列的基本知识可能为理解加速尾矿上土壤形成所需的成土过程提供一个有启发性的模型。在尾矿上进行成功的生态恢复，功能性、稳定的根区的发展至关重要，应尽早在处理过程中或恢复的早期阶段促进三个主要过程，以加速碱性尾矿上的土壤发育：i）尾矿上层剖面的酸化；ii）建立适当和有弹性的微生物群落；iii）适当的先锋植被的早期发展。在尾矿地貌上实现成功的生态恢复结果可能是恢复生态学家和采矿业面临的最大挑战之一，而在碱性尾矿上的成功恢复可能取决于通过有针对性的改良剂对基质化学条件的精心管理。
