Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China.
Technical Innovation Center of Mine Geological Environmental Restoration Engineering in Southern Karst Area, MNR, Guilin 541004, China.
Sci Total Environ. 2022 Dec 20;853:158291. doi: 10.1016/j.scitotenv.2022.158291. Epub 2022 Aug 27.
A major challenge for the restoration of the Lead-Zinc tailing pond in Karst areas lies in how to establish vegetation with less soil and restore the ecological functions of the substrate. In this study, a novel method, rhizosphere soil cover method (RSC), was applied to recover the vegetation at a Pb-Zn tailing pond in Karst areas. Two local tolerate plants, Miscanthus sinensis and Pueraria phaseoloides, were planted as pioneer species. Although 68 % of the tailing pond was not covered with soil, the vegetation coverage has reached over 90 % after restoration for three years. Compared with the natural revegetation process (vegetation coverage was <5 % after 20 years of natural succession), the revegetation in the tailing pond was accelerated by RSC and planting pioneer species. Both the plant's diversity and richness have significantly increased in the tailings pond during the restoration (p < 0.05). The important value indicators of M. sinensis and P. phaseoloides were the highest in the plant community, indicating the dominant role of these two plants in revegetation. Moreover, the total organic carbon, total nitrogen, total phosphorus, and total potassium in the tailings increased annually (p < 0.05), which demonstrated that the revegetation has improved the chemical properties in the substrate. In addition, the Shannon diversity index of bacteria in the tailings increased significantly from 4.11 to 5.51. The relative abundance of microbial genes related to carbon fixation and nitrogen fixation in the tailings increased by 17 % and 43 %, respectively. Meanwhile, the physicochemical properties, microbial community structure, and nutrient cycling function in the tailings without topsoil were improved more obviously than those in soils. It is thereby concluded that RSC is an efficient means for ecological restoration of the tailing ponds in Karst areas to improve the ecosystem structure and function of Pb-Zn tailings.
在喀斯特地区，铅锌尾矿库植被恢复的一个主要挑战在于如何在土壤较少的情况下建立植被，并恢复基质的生态功能。本研究采用根际土壤覆盖法（RSC）恢复喀斯特地区铅锌尾矿库植被。种植了两种当地耐受植物，芒属植物和葛藤作为先锋物种。尽管尾矿库 68%的区域没有土壤覆盖，但经过三年的恢复，植被覆盖率已超过 90%。与自然植被恢复过程（自然演替 20 年后植被覆盖率<5%）相比，RSC 和种植先锋物种加速了尾矿库的植被恢复。在恢复过程中，尾矿库中的植物多样性和丰富度都显著增加（p<0.05）。芒属植物和葛藤在植物群落中的重要值指标最高，表明这两种植物在植被恢复中起主导作用。此外，尾矿中的总有机碳、总氮、总磷和总钾含量逐年增加（p<0.05），表明植被恢复改善了基质的化学性质。此外，尾矿中细菌的 Shannon 多样性指数从 4.11 显著增加到 5.51。尾矿中与固碳和固氮相关的微生物基因的相对丰度分别增加了 17%和 43%。同时，无表土尾矿的理化性质、微生物群落结构和养分循环功能的改善比土壤中更为明显。因此，RSC 是一种有效的喀斯特地区尾矿库生态恢复方法，可以改善铅锌尾矿的生态系统结构和功能。
