Pedosphere 34(4): 826--836, 2024
ISSN 1002-0160/CN 32-1315/P
©2024 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Changes of nutrients and microbial communities in recovery process of abandoned rare earth tailings |
Bing ZHANG1, Junli WU2, Mengyuan HUANG2, Yan ZHANG2, Jin ZHAO2, Chuntao HE3 , Zhongyi YANG2 |
1 School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006 (China);
2 School of Life Sciences, Sun Yat-sen University, Guangzhou 510275 (China);
3 School of Agriculture, State Key Laboratory for Biocontrol, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen 518107 (China) |
| ABSTRACT |
| Rare earth element (REE) mining has wrought severe ecosystem destruction, particularly in the loss of carbon (C), nitrogen (N), and phosphorus (P). Furthermore, its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood. In this study, an investigation was conducted to determine C, N, and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5 (1.5-Y), 7 (7-Y), 10 (10-Y), and 14 (14-Y) years and at an unmined site (the control group) in Jiangxi Province, China. Longitudinal tailing delamination at each site was investigated in 0–15 (layer 1) and 15–30 (layer 2) cm tailing layers. During the abandoned duration of REE tailings, C and P in layer 1 continued to recover from 1.62 to 8.51 g kg-1 and from 0.71 to 1.94 g kg-1, respectively; N losses of 0.60 and 0.22 g kg-1 occurred at the 1.5-Y and 10-Y sites, while N in layer 1 slightly increased at the 14-Y site. Mesorhizobium, Methylosinus, Bradyrhizobium, Pseudomonas, and Azospirillum were dominant bacteria at the 14-Y site and in the control. The relative abundances of N-fixing bacteria Mesorhizobium (32.94%), Sinorhizobium (0.24%), Frankia (0.71%), and Burkholderia (2.38%) at the 14-Y site were 1.33–3.97 times those in the control (24.19%, 0.18%, 0.32% and 0.60%, respectively), which was helpful for tailing N recovery. At the 14-Y site, Tylospora (50.24%), Luellia (11.02%), Tomentella (6.94%), and Chaetomium (4.34%) were the dominant fungal genera, while Tylospora (56.93%), Suillus (11.45%), and Penicillium (6.78%) predominated in the control. The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site (0.42%) was 4.2 times that in the control (0.1%), which may lead to the improved tailing P solubility. At the 14-Y site, woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas. This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings, thus providing a novel insight into ecological recovery and restoration after mining. |
| Key Words: abandoned duration,mining tailing,N-fixing bacteria,nutrient recovery,P-solubilizing fungi,rare earth element |
| Citation: Zhang B, Wu J L, Huang M Y, Zhang Y, Zhao J, He C T, Yang Z Y. 2024. Changes of nutrients and microbial communities in recovery process of abandoned rare earth tailings. Pedosphere. 34(4): 826–836. |
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