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Samad A, Degenhardt D, Séguin A, Morency MJ, Gagné P, Martineau C. Microbial community structural and functional differentiation in capped thickened oil sands tailings planted with native boreal species. Front Microbiol 2023; 14:1168653. [PMID: 37465026 PMCID: PMC10350512 DOI: 10.3389/fmicb.2023.1168653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/12/2023] [Indexed: 07/20/2023] Open
Abstract
The oil sands mining operations in Alberta have produced billions of m3 of tailings which must be reclaimed and integrated into various mine closure landforms, including terrestrial landforms. Microorganisms play a central role in nutrient cycling during the reclamation of disturbed landscapes, contributing to successful vegetation restoration and long-term sustainability. However, microbial community succession and response in reconstructed and revegetated tailings remain largely unexplored. This study aimed to monitor the structural and functional responses of microbial communities in tailings subjected to different capping and vegetation strategies over two growing seasons (GS). To achieve this, a column-based greenhouse experiment was conducted to investigate microbial communities in tailings that were capped with a layer (10 or 30 cm) of peat-mineral mix (PMM) and planted with either upland or wetland communities. DNA metabarcoding analysis of the bacterial 16S rRNA gene and fungal ITS2 region as well as shotgun metagenomics were used to asses the impact of treatments on microbial taxonomy and functions, respectively. Results showed that tailings microbial diversity and community composition changed considerably after two GS compared to baseline samples, while communities in the PMM capping layer were much more stable. Likewise, several microbial functions were significantly enriched in tailings after two GS. Interestingly, the impact of capping on bacterial communities in tailings varied depending on the plant community, leading to a higher number of differentially abundant taxa and to a decrease in Shannon diversity and evenness in the upland treatment but not in the wetland treatment. Moreover, while capping in the presence of wetland vegetation increased the energy-related metabolic functions (carbon, nitrogen, and sulfur), these functions were depleted by capping in the upland treatment. Fungi represented a small proportion of the microbial community in tailings, but the relative abundance of several taxa changed over time, while the capping treatments favored the growth of some beneficial taxa, notably the root endophyte Serendipita, in both upland and wetland columns. The results suggest that selecting the right combination of capping material and vegetation type may contribute to improve below-ground microbial processes and sustain plant growth in harsh environments such as oil sands tailings.
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Affiliation(s)
- Abdul Samad
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada
| | - Dani Degenhardt
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB, Canada
| | - Armand Séguin
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada
| | - Marie-Josée Morency
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada
| | - Patrick Gagné
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada
| | - Christine Martineau
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada
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Jiang M, He L, Fan B, Wang T, Yang N, Liu Y, Xu Y, Dong K, Hao G, Chen L, Ren A, Zhao N, Wang J, Gao Y. Intraspecific more than interspecific diversity plays an important role on Inner Mongolia grassland ecosystem functions: A microcosm experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 826:154134. [PMID: 35219658 DOI: 10.1016/j.scitotenv.2022.154134] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Biodiversity changes in terrestrial communities continue in the context of global changes. However, the interactive effects of the changes in diversity at inter- and intraspecific levels as well as cascading effects from plant to soil microorganisms on ecosystem functioning under climate changes remains largely unexplored. Using grassland species in the semi-arid Inner Mongolia Steppe, we conducted a microcosm experiment to assess how drought treatment (non-drought and drought conditions), species diversity (2, 4, and 7 species) and genotypic diversity of the dominant species Leymus chinensis (1, 3, and 6 genotypes) affected ecosystem functions directly or indirectly via regulating plant community functional structure [community-weighted mean (CWM) and functional dispersion (FDis)] and soil microbial diversity (Shannon-Wiener index). Drought treatment, species and genotypic diversity significantly and interactively affected soil N, P cycle and soil multifunctionality as well as soil microbial diversity. Drought treatment significantly affected biomass, soil C cycle, CWM and soil microbial diversity. Species diversity significantly affected soil N cycle, CWM and FDis, and genotypic diversity significantly affected all soil functions and soil microbial diversity. CWM regulated the responses of all ecosystem functions except soil N cycle to the changes in soil moisture and species diversity, which supports the mass ratio hypothesis. The cascading effect from genotypic diversity to soil microbial diversity was significant on belowground biomass but not on any of the other ecosystem functions observed in this study. These findings highlight the importance of genotypic diversity of the dominant species L. chinensis in affecting belowground ecosystem functioning as well as soil microbial diversity, which should not be ignored for grassland protection and management. This study provides further insights into biodiversity and ecosystem functioning mechanisms in semi-arid grasslands in the context of global climate changes.
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Affiliation(s)
- Man Jiang
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Luoyang He
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Baijie Fan
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Tao Wang
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Nan Yang
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Yulin Liu
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Yujuan Xu
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Ke Dong
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Guang Hao
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Lei Chen
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Anzhi Ren
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
| | - Nianxi Zhao
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China.
| | - Jinlong Wang
- College of Agronomy & Resources and Environment, Tianjin Agricultural University, No. 22 Jinjing Road, Tianjin 300384, PR China
| | - Yubao Gao
- Department of Plant Biology and Ecology, College of Life Science, Nankai University, No. 94 Weijin Road, Tianjin 300071, PR China
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