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Li D, Zhang Y, Yu F, Wang J, Zhang X, Feng L, Lang T, Yang F. Vadose-zone characteristic pollutants distribution, microbial community structure and functionality changes in response to long-term leachate pollution of an informal landfill site. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174596. [PMID: 38997023 DOI: 10.1016/j.scitotenv.2024.174596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/26/2024] [Accepted: 07/05/2024] [Indexed: 07/14/2024]
Abstract
The study embarked on a comprehensive examination of the evolution and diversity of microorganisms within long-term leachate pollution environments, with a focus on varying depths and levels of contamination, and its linkage to soil characteristics and the presence of heavy metals. It was observed that microbial diversity presented distinct cross-depth trend, where archaeal communities were found to be particularly sensitive to alterations in soil depth. Noteworthily, Euryarchaeota increased by 4.82 %, 7.64 % and 9.87 % compared with topsoil. The abundance of Tahumarchaeota was successively reduced by 5.79 %, 9.58 %, and 12.66 %. The bacterial community became more sensitive to leachate pollution, and the abundance of Protebacteria in contaminated soil decreased by 10.27 %, while the abundance of Firmicutes increased by 7.46 %. The bacterial genus Gemmobacter, Chitinophaga and Rheinheimera; the archaeal genus Methanomassiliicoccus and Nitrosopumilus; along with the fungal genus Goffeauzyma, Gibberella, and Setophaeosphaeria emerged as pivotal biological markers for their respective domains, underpinning the biogeochemical dynamics of these environments. Furthermore, the study highlighted that geochemical factors, specifically nitrate (NO₃--N) levels and humic acid (HA) fractions, played crucial roles in modulating the composition and metabolic potential of these communities. Predictive analyses of functional potentials suggested that the N functional change of archaea was more pronounced, with anaerobic ammonia oxidation and nitrification decreased by 15.78 % and 14.62 %, respectively. Overall, soil characteristics alone explained 57.9 % of the total variation in the bacterial community structure. For fungal communities within contaminated soil, HMs were the primary contributors, explaining 46.9 % of the variability, while soil depth accounting for 6.4 % of the archaeal variation. This research enriches the understanding of the complex interrelations between heavy metal pollution, soil attributes, and microbial communities, paving the way for informed strategies in managing informal landfill sites effectively.
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Affiliation(s)
- Dong Li
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China
| | - Yuling Zhang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China.
| | - Furong Yu
- North China University of Water Resources and Electric Power, Zhengzhou 450046, China
| | - Jili Wang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China
| | - Xinying Zhang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China
| | - Liuyuan Feng
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China
| | - Tao Lang
- North China University of Water Resources and Electric Power, Zhengzhou 450046, China
| | - Fengtian Yang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; College of New Energy and Environment, Jilin University, Changchun 130021, China; Institute of Water Resources and Environment, Jilin University, Changchun 130021, China.
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Li Y, Xue Y, Roy Chowdhury T, Graham DE, Tringe SG, Jansson JK, Taş N. Genomic insights into redox-driven microbial processes for carbon decomposition in thawing Arctic soils and permafrost. mSphere 2024; 9:e0025924. [PMID: 38860762 PMCID: PMC11288003 DOI: 10.1128/msphere.00259-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 05/03/2024] [Indexed: 06/12/2024] Open
Abstract
Climate change is rapidly transforming Arctic landscapes where increasing soil temperatures speed up permafrost thaw. This exposes large carbon stocks to microbial decomposition, possibly worsening climate change by releasing more greenhouse gases. Understanding how microbes break down soil carbon, especially under the anaerobic conditions of thawing permafrost, is important to determine future changes. Here, we studied the microbial community dynamics and soil carbon decomposition potential in permafrost and active layer soils under anaerobic laboratory conditions that simulated an Arctic summer thaw. The microbial and viral compositions in the samples were analyzed based on metagenomes, metagenome-assembled genomes, and metagenomic viral contigs (mVCs). Following the thawing of permafrost, there was a notable shift in microbial community structure, with fermentative Firmicutes and Bacteroidota taking over from Actinobacteria and Proteobacteria over the 60-day incubation period. The increase in iron and sulfate-reducing microbes had a significant role in limiting methane production from thawed permafrost, underscoring the competition within microbial communities. We explored the growth strategies of microbial communities and found that slow growth was the major strategy in both the active layer and permafrost. Our findings challenge the assumption that fast-growing microbes mainly respond to environmental changes like permafrost thaw. Instead, they indicate a common strategy of slow growth among microbial communities, likely due to the thermodynamic constraints of soil substrates and electron acceptors, and the need for microbes to adjust to post-thaw conditions. The mVCs harbored a wide range of auxiliary metabolic genes that may support cell protection from ice formation in virus-infected cells. IMPORTANCE As the Arctic warms, thawing permafrost unlocks carbon, potentially accelerating climate change by releasing greenhouse gases. Our research delves into the underlying biogeochemical processes likely mediated by the soil microbial community in response to the wet and anaerobic conditions, akin to an Arctic summer thaw. We observed a significant shift in the microbial community post-thaw, with fermentative bacteria like Firmicutes and Bacteroidota taking over and switching to different fermentation pathways. The dominance of iron and sulfate-reducing bacteria likely constrained methane production in the thawing permafrost. Slow-growing microbes outweighed fast-growing ones, even after thaw, upending the expectation that rapid microbial responses to dominate after permafrost thaws. This research highlights the nuanced and complex interactions within Arctic soil microbial communities and underscores the challenges in predicting microbial response to environmental change.
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Affiliation(s)
- Yaoming Li
- College of Grassland Science, Beijing Forest University, Beijing, China
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Yaxin Xue
- Data Sciences and Quantitative Biology, Discovery Sciences, AstraZeneca R&D, Cambridge, United Kingdom
| | | | - David E. Graham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Susannah G. Tringe
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Janet K. Jansson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Neslihan Taş
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Rafie SAA, Blentlinger LR, Putt AD, Williams DE, Joyner DC, Campa MF, Schubert MJ, Hoyt KP, Horn SP, Franklin JA, Hazen TC. Impact of prescribed fire on soil microbial communities in a Southern Appalachian Forest clear-cut. Front Microbiol 2024; 15:1322151. [PMID: 38741734 PMCID: PMC11090169 DOI: 10.3389/fmicb.2024.1322151] [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: 10/15/2023] [Accepted: 04/08/2024] [Indexed: 05/16/2024] Open
Abstract
Escalating wildfire frequency and severity, exacerbated by shifting climate patterns, pose significant ecological and economic challenges. Prescribed burns, a common forest management tool, aim to mitigate wildfire risks and protect biodiversity. Nevertheless, understanding the impact of prescribed burns on soil and microbial communities in temperate mixed forests, considering temporal dynamics and slash fuel types, remains crucial. Our study, conducted at the University of Tennessee Forest Resources AgResearch and Education Center in Oak Ridge, TN, employed controlled burns across various treatments, and the findings indicate that low-intensity prescribed burns have none or minimal short-term effects on soil parameters but may alter soil nutrient concentrations, as evidenced by significant changes in porewater acetate, formate, and nitrate concentrations. These burns also induce shifts in microbial community structure and diversity, with Proteobacteria and Acidobacteria increasing significantly post-fire, possibly aiding soil recovery. In contrast, Verrucomicrobia showed a notable decrease over time, and other specific microbial taxa correlated with soil pH, porewater nitrate, ammonium, and phosphate concentrations. Our research contributes to understanding the intricate relationships between prescribed fire, soil dynamics, and microbial responses in temperate mixed forests in the Southern Appalachian Region, which is valuable for informed land management practices in the face of evolving environmental challenges.
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Affiliation(s)
- S. A. A. Rafie
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, United States
- Institute for a Secure and Sustainable Environment, University of Tennessee, Knoxville, TN, United States
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - L. R. Blentlinger
- Department of Geography, University of Tennessee, Knoxville, TN, United States
| | - A. D. Putt
- Institute for a Secure and Sustainable Environment, University of Tennessee, Knoxville, TN, United States
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, United States
| | - D. E. Williams
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, United States
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - D. C. Joyner
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, United States
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - M. F. Campa
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, United States
- Bredesen Center—Genome Science and Technology, University of Tennessee, Knoxville, TN, United States
| | - M. J. Schubert
- Forest Resources AgResearch and Education Center, Knoxville, TN, United States
| | - K. P. Hoyt
- Forest Resources AgResearch and Education Center, Knoxville, TN, United States
| | - S. P. Horn
- Department of Geography, University of Tennessee, Knoxville, TN, United States
| | - J. A. Franklin
- Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, United States
| | - T. C. Hazen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, United States
- Institute for a Secure and Sustainable Environment, University of Tennessee, Knoxville, TN, United States
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, United States
- Bredesen Center—Genome Science and Technology, University of Tennessee, Knoxville, TN, United States
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Liu Z, Gu H, Yao Q, Jiao F, Hu X, Liu J, Jin J, Liu X, Wang G. Soil pH and carbon quality index regulate the biogeochemical cycle couplings of carbon, nitrogen and phosphorus in the profiles of Isohumosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171269. [PMID: 38423323 DOI: 10.1016/j.scitotenv.2024.171269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 02/13/2024] [Accepted: 02/23/2024] [Indexed: 03/02/2024]
Abstract
Soil biogeochemical cycles are essential for regulating ecosystem functions and services. However, little knowledge has been revealed on microbe-driven biogeochemical processes and their coupling mechanisms in soil profiles. This study investigated the vertical distribution of soil functional composition and their contribution to carbon (C), nitrogen (N) and phosphorus (P) cycling in the humus horizons (A-horizons) and parent material horizons (C-horizons) in Udic and Ustic Isohumosols using shotgun sequencing. Results showed that the diversity and relative abundance of microbial functional genes was influenced by soil horizons and soil types. In A-horizons, the relative abundances of N mineralization and liable C decomposition genes were significantly greater, but the P cycle-related genes, recalcitrant C decomposition and denitrification genes were lower compared to C-horizons. While, Ustic Isohumosols had lower relative abundances of C decomposition genes but higher relative abundances of N mineralization and P cycling-related pathways compared to Udic Isohumosols. The network analysis revealed that C-horizons had more interactions and stronger stability of functional gene networks than in A-horizons. Importantly, our results provide new insights into the potential mechanisms for the coupling processes of soil biogeochemical cycles among C, N and P, which is mediated by specific microbial taxa. Soil pH and carbon quality index (CQI) were two sensitive indicators for regulating the relative abundances and the relationships of functional genes in biogeochemical cycles. This study contributes to a deeper understanding of the ecological functions of soil microorganisms, thus providing a theoretical basis for the exploration and utilization of soil microbial resources and the development of soil ecological control strategies.
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Affiliation(s)
- Zhuxiu Liu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Haidong Gu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qin Yao
- College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Feng Jiao
- College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Xiaojing Hu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Junjie Liu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
| | - Jian Jin
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Xiaobing Liu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Guanghua Wang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
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Ma L, Zhou G, Zhang J, Jia Z, Zou H, Chen L, Zhang C, Ma D, Han C, Duan Y. Long-term conservation tillage enhances microbial carbon use efficiency by altering multitrophic interactions in soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:170018. [PMID: 38224879 DOI: 10.1016/j.scitotenv.2024.170018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 12/03/2023] [Accepted: 01/06/2024] [Indexed: 01/17/2024]
Abstract
Microbial carbon (C) use efficiency (CUE) plays a key role in soil C storage. The predation of protists on bacteria and fungi has potential impacts on the global C cycle. However, under conservation tillage conditions, the effects of multitrophic interactions on soil microbial CUE are still unclear. Here, we investigate the multitrophic network (especially the keystone ecological cluster) and its regulation of soil microbial CUE and soil organic C (SOC) under different long-term (15-year) tillage practices. We found that conservation tillage (CT) significantly enhanced microbial CUE, turnover, and SOC (P < 0.05) compared to traditional tillage (control, CK). At the same time, tillage practice and soil depth had significant effects on the structure of fungal and protistan communities. Furthermore, the soil biodiversity of the keystone cluster was positively correlated with the microbial physiological traits (CUE, microbial growth rate (MGR), microbial respiration rate (Rs), microbial turnover) and SOC (P < 0.05). Protistan richness played the strongest role in directly shaping the keystone cluster. Compared with CK, CT generally enhanced the correlation between microbial communities and microbial physiological characteristics and SOC. Overall, our results illustrate that the top-down control (the organisms at higher trophic levels affect the organisms at lower trophic levels) of protists in the soil micro-food web plays an important role in improving microbial CUE under conservation tillage. Our findings provide a theoretical basis for promoting the application of protists in targeted microbial engineering and contribute to the promotion of conservation agriculture and the improvement of soil C sequestration potential.
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Affiliation(s)
- Ling Ma
- College of Land and Environment, Shenyang Agricultural University, National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Arable Land Conservation in Northeast China, Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Guixiang Zhou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jiabao Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Zhongjun Jia
- Chinese Academy of Sciences, Northeast Institute of Geography and Agroecology, Changchun 130102, China
| | - Hongtao Zou
- College of Land and Environment, Shenyang Agricultural University, National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Arable Land Conservation in Northeast China, Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Lin Chen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Congzhi Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Donghao Ma
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Changdong Han
- College of Land and Environment, Shenyang Agricultural University, National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Arable Land Conservation in Northeast China, Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Yan Duan
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
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Li H, Zou Y, Song W, Xin J, Gao J. Effects of frequency and amount of stover mulching on the microbial community composition and structure in the endosphere and rhizosphere. Front Microbiol 2024; 15:1372471. [PMID: 38468854 PMCID: PMC10925793 DOI: 10.3389/fmicb.2024.1372471] [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: 01/18/2024] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
Stover mulching, as a sustainable agricultural conservation practice, has been shown to effectively increase soil organic matter and enhance crop yields. The impact of stover mulching on soil microorganisms has been extensively studied. However, less attention has been given to endophytic and rhizospheric microorganisms that have closer relationships with crops. How do the quality and frequency of stover mulching affect the composition and structure of these endosphere and rhizosphere microbial communities? And what is their influence on critical indicators of soil health such as bacterial plant pathogen and Rhizobiales? These questions remain unresolved. Therefore, we investigated the responses of the microbial functional guilds in the endosphere and rhizosphere to maize stover mulching qualities (0%, 33%, 67%, and total stover mulching every year) and frequencies (once every 3 years and twice every 3 years) under 10-year no-till management. Results showed significant correlations between Bacillales and Rhizobiales orders and soil SOC, NO3-N, and NH4+N; Hypocreales and Eurotiales orders were significantly correlated with soil NO3-N, with the Aspergillus genus also showing a significant correlation with soil SOC. The frequency and quality of stover mulching had a significant effect on root and rhizospheric microbial communities, with the lowest relative abundance of bacterial plant pathogens and highest relative abundance of nitrogen-fixing bacteria such as Rhizobiales and Hypocreales observed under F1/3 and F2/3 conditions. The most complex structures in endosphere and rhizospheric microbial communities were found under Q33 and Q67 conditions, respectively. This research indicates that from a soil health perspective, low-frequency high-coverage stover mulching is beneficial for the composition of endosphere and rhizosphere microbial communities, while moderate coverage levels are conducive to more complex structures within these communities. This study holds significant ecological implications for agricultural production and crop protection.
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Affiliation(s)
- Haowen Li
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Yawen Zou
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Wenchen Song
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Jiaxun Xin
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Jian Gao
- School of Ecology and Environment, Baotou Teachers’ College, Inner Mongolia University of Science and Technology, Baotou, China
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Bandla A, Akhtar H, Lupascu M, Sukri RS, Swarup S. Elevated methane flux in a tropical peatland post-fire is linked to depth-dependent changes in peat microbiome assembly. NPJ Biofilms Microbiomes 2024; 10:8. [PMID: 38253600 PMCID: PMC10803758 DOI: 10.1038/s41522-024-00478-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Fires in tropical peatlands extend to depth, transforming them from carbon sinks into methane sources and severely limit forest recovery. Peat microbiomes influence carbon transformations and forest recovery, yet our understanding of microbiome shifts post-fire is currently limited. Our previous study highlighted altered relationships between the peat surface, water table, aboveground vegetation, and methane flux after fire in a tropical peatland. Here, we link these changes to post-fire shifts in peat microbiome composition and assembly processes across depth. We report kingdom-specific and depth-dependent shifts in alpha diversity post-fire, with large differences at deeper depths. Conversely, we found shifts in microbiome composition across all depths. Compositional shifts extended to functional groups involved in methane turnover, with methanogens enriched and methanotrophs depleted at mid and deeper depths. Finally, we show that community shifts at deeper depths result from homogeneous selection associated with post-fire changes in hydrology and aboveground vegetation. Collectively, our findings provide a biological basis for previously reported methane fluxes after fire and offer new insights into depth-dependent shifts in microbiome assembly processes, which ultimately underlie ecosystem function predictability and ecosystem recovery.
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Affiliation(s)
- Aditya Bandla
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Hasan Akhtar
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Department of Geography, National University of Singapore, Singapore, Singapore
- School of Liberal Arts and Sciences, RV University, Bengaluru, Karnataka, India
| | - Massimo Lupascu
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Department of Geography, National University of Singapore, Singapore, Singapore
| | - Rahayu Sukmaria Sukri
- Institute for Biodiversity and Environmental Research, Universiti Brunei Darussalam, Gadong, Brunei Darussalam
| | - Sanjay Swarup
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore.
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore.
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
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Barbour KM, Weihe C, Walters KE, Martiny JBH. Testing the contribution of dispersal to microbial succession following a wildfire. mSystems 2023; 8:e0057923. [PMID: 37747204 PMCID: PMC10654055 DOI: 10.1128/msystems.00579-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/28/2023] [Indexed: 09/26/2023] Open
Abstract
IMPORTANCE Identifying the mechanisms underlying microbial community succession is necessary for predicting how microbial communities, and their functioning, will respond to future environmental change. Dispersal is one mechanism expected to affect microbial succession, yet the difficult nature of manipulating microorganisms in the environment has limited our understanding of its contribution. Using a dispersal exclusion experiment, this study isolates the specific effect of environmental dispersal on bacterial and fungal community assembly over time following a wildfire. The work demonstrates the potential to quantify dispersal impacts on soil microbial communities over time and test how dispersal might further interact with other assembly processes in response to environmental change.
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Affiliation(s)
- Kristin M. Barbour
- Department of Ecology and Evolutionary Biology, University of California-Irvine, Irvine, California, USA
| | - Claudia Weihe
- Department of Ecology and Evolutionary Biology, University of California-Irvine, Irvine, California, USA
| | | | - Jennifer B. H. Martiny
- Department of Ecology and Evolutionary Biology, University of California-Irvine, Irvine, California, USA
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Chen L, Hong T, Wu Z, Song W, Chen SX, Liu Y, Shen L. Genomic analyses reveal a low-temperature adapted clade in Halorubrum, a widespread haloarchaeon across global hypersaline environments. BMC Genomics 2023; 24:508. [PMID: 37653415 PMCID: PMC10468875 DOI: 10.1186/s12864-023-09597-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/16/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND Cold-adapted archaea have diverse ecological roles in a wide range of low-temperature environments. Improving our knowledge of the genomic features that enable psychrophiles to grow in cold environments helps us to understand their adaptive responses. However, samples from typical cold regions such as the remote Arctic and Antarctic are rare, and the limited number of high-quality genomes available leaves us with little data on genomic traits that are statistically associated with cold environmental conditions. RESULTS In this study, we examined the haloarchaeal genus Halorubrum and defined a new clade that represents six isolates from polar and deep earth environments ('PD group' hereafter). The genomic G + C content and amino acid composition of this group distinguishes it from other Halorubrum and the trends are consistent with the established genomic optimization of psychrophiles. The cold adaptation of the PD group was further supported by observations of increased flexibility of proteins encoded across the genome and the findings of a growth test. CONCLUSIONS The PD group Halorubrum exhibited denser genome packing, which confers higher metabolic potential with constant genome size, relative to the reference group, resulting in significant differences in carbon, nitrogen and sulfur metabolic patterns. The most marked feature was the enrichment of genes involved in sulfur cycling, especially the production of sulfite from organic sulfur-containing compounds. Our study provides an updated view of the genomic traits and metabolic potential of Halorubrum and expands the range of sources of cold-adapted haloarchaea.
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Affiliation(s)
- Liangzhong Chen
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
- Anhui Provincial Key Laboratory of Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, and Auhui Provincial Engineering Research Centre for Molecular Detection and Diagnostics, Anhui Normal University, Wuhu, 241000, China
| | - Tao Hong
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Zirui Wu
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Weizhi Song
- Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Shaoxing X Chen
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China.
| | - Yongqin Liu
- Center for the Pan-third Pole Environment, Lanzhou University, Lanzhou, 730000, China
- State Key Laboratory of Tibetan Plateau Earth System Science, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 100085, Beijing, China
| | - Liang Shen
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China.
- Anhui Provincial Key Laboratory of Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, China.
- State Key Laboratory of Tibetan Plateau Earth System Science, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 100085, Beijing, China.
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Sannino C, Qi W, Rüthi J, Stierli B, Frey B. Distinct taxonomic and functional profiles of high Arctic and alpine permafrost-affected soil microbiomes. ENVIRONMENTAL MICROBIOME 2023; 18:54. [PMID: 37328770 DOI: 10.1186/s40793-023-00509-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Global warming is affecting all cold environments, including the European Alps and Arctic regions. Here, permafrost may be considered a unique ecosystem harboring a distinct microbiome. The frequent freeze-thaw cycles occurring in permafrost-affected soils, and mainly in the seasonally active top layers, modify microbial communities and consequently ecosystem processes. Although taxonomic responses of the microbiomes in permafrost-affected soils have been widely documented, studies about how the microbial genetic potential, especially pathways involved in C and N cycling, changes between active-layer soils and permafrost soils are rare. Here, we used shotgun metagenomics to analyze the microbial and functional diversity and the metabolic potential of permafrost-affected soil collected from an alpine site (Val Lavirun, Engadin area, Switzerland) and a High Arctic site (Station Nord, Villum Research Station, Greenland). The main goal was to discover the key genes abundant in the active-layer and permafrost soils, with the purpose to highlight the potential role of the functional genes found. RESULTS We observed differences between the alpine and High Arctic sites in alpha- and beta-diversity, and in EggNOG, CAZy, and NCyc datasets. In the High Arctic site, the metagenome in permafrost soil had an overrepresentation (relative to that in active-layer soil) of genes involved in lipid transport by fatty acid desaturate and ABC transporters, i.e. genes that are useful in preventing microorganisms from freezing by increasing membrane fluidity, and genes involved in cell defense mechanisms. The majority of CAZy and NCyc genes were overrepresented in permafrost soils relative to active-layer soils in both localities, with genes involved in the degradation of carbon substrates and in the degradation of N compounds indicating high microbial activity in permafrost in response to climate warming. CONCLUSIONS Our study on the functional characteristics of permafrost microbiomes underlines the remarkably high functional gene diversity of the High Arctic and temperate mountain permafrost, including a broad range of C- and N-cycling genes, and multiple survival and energetic metabolisms. Their metabolic versatility in using organic materials from ancient soils undergoing microbial degradation determine organic matter decomposition and greenhouse gas emissions upon permafrost thawing. Attention to their functional genes is therefore essential to predict potential soil-climate feedbacks to the future warmer climate.
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Affiliation(s)
- Ciro Sannino
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | - Weihong Qi
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics SIB, Geneva, Switzerland
| | - Joel Rüthi
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Beat Stierli
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland.
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11
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Waldrop MP, Chabot CL, Liebner S, Holm S, Snyder MW, Dillon M, Dudgeon SR, Douglas TA, Leewis MC, Walter Anthony KM, McFarland JW, Arp CD, Bondurant AC, Taş N, Mackelprang R. Permafrost microbial communities and functional genes are structured by latitudinal and soil geochemical gradients. THE ISME JOURNAL 2023:10.1038/s41396-023-01429-6. [PMID: 37217592 DOI: 10.1038/s41396-023-01429-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/24/2023]
Abstract
Permafrost underlies approximately one quarter of Northern Hemisphere terrestrial surfaces and contains 25-50% of the global soil carbon (C) pool. Permafrost soils and the C stocks within are vulnerable to ongoing and future projected climate warming. The biogeography of microbial communities inhabiting permafrost has not been examined beyond a small number of sites focused on local-scale variation. Permafrost is different from other soils. Perennially frozen conditions in permafrost dictate that microbial communities do not turn over quickly, thus possibly providing strong linkages to past environments. Thus, the factors structuring the composition and function of microbial communities may differ from patterns observed in other terrestrial environments. Here, we analyzed 133 permafrost metagenomes from North America, Europe, and Asia. Permafrost biodiversity and taxonomic distribution varied in relation to pH, latitude and soil depth. The distribution of genes differed by latitude, soil depth, age, and pH. Genes that were the most highly variable across all sites were associated with energy metabolism and C-assimilation. Specifically, methanogenesis, fermentation, nitrate reduction, and replenishment of citric acid cycle intermediates. This suggests that adaptations to energy acquisition and substrate availability are among some of the strongest selective pressures shaping permafrost microbial communities. The spatial variation in metabolic potential has primed communities for specific biogeochemical processes as soils thaw due to climate change, which could cause regional- to global- scale variation in C and nitrogen processing and greenhouse gas emissions.
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Affiliation(s)
- Mark P Waldrop
- Geology, Minerals, Energy, and Geophysics Science Center, United States Geological Survey, Menlo Park, CA, 94025, USA.
| | - Christopher L Chabot
- California State University Northridge, 18111 Nordhoff St., Northridge, CA, 91330, USA
| | - Susanne Liebner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473, Potsdam, Germany
- University of Potsdam, Institute of Biochemistry and Biology, 14476, Potsdam, Germany
| | - Stine Holm
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473, Potsdam, Germany
| | - Michael W Snyder
- California State University Northridge, 18111 Nordhoff St., Northridge, CA, 91330, USA
| | - Megan Dillon
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Steven R Dudgeon
- California State University Northridge, 18111 Nordhoff St., Northridge, CA, 91330, USA
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory 9th Avenue, Building 4070 Fort, Wainwright, AK, 99703, USA
| | - Mary-Cathrine Leewis
- Agriculture and Agri-Food Canada, 2560 Boulevard Hochelaga, Québec, QC, G1V 2J3, Canada
| | - Katey M Walter Anthony
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Jack W McFarland
- Geology, Minerals, Energy, and Geophysics Science Center, United States Geological Survey, Menlo Park, CA, 94025, USA
| | - Christopher D Arp
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Allen C Bondurant
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Neslihan Taş
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Rachel Mackelprang
- California State University Northridge, 18111 Nordhoff St., Northridge, CA, 91330, USA.
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12
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Abstract
Soil viruses are highly abundant and have important roles in the regulation of host dynamics and soil ecology. Climate change is resulting in unprecedented changes to soil ecosystems and the life forms that reside there, including viruses. In this Review, we explore our current understanding of soil viral diversity and ecology, and we discuss how climate change (such as extended and extreme drought events or more flooding and altered precipitation patterns) is influencing soil viruses. Finally, we provide our perspective on future research needs to better understand how climate change will impact soil viral ecology.
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Affiliation(s)
- Janet K Jansson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA.
| | - Ruonan Wu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
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13
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Liu X, Zhou W, Wang X, Wu H, Dong W. Microbial gradual shifts during the process of species replacement in Taihang Mountain. Front Microbiol 2023; 14:1158731. [PMID: 37089536 PMCID: PMC10113637 DOI: 10.3389/fmicb.2023.1158731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/16/2023] [Indexed: 04/08/2023] Open
Abstract
IntroductionUnderstanding microbial gradual shifts along species replacement can help elucidate the mechanisms driving secondary succession, and predict microbial responses to changing environments. However, how climate-induced species replacement alters microbial processes, and whether microbial shifts follow predictable assembly trajectories remain unclear.MethodsUsing space-for-time substitution approach, we studied shifts in bacterial and fungal communities in the succession from Leptodermis oblonga to Vitex negundo var. heterophylla shrubland in Taihang Mountain.Results and DiscussionSpecies replacement, induced by climate related environmental change, significantly increased the above-ground biomass of shrublands, and TP and TK contents in topsoil. The succession from L. oblonga to V. negundo var. heterophylla communities resulted in the gradually replacement of cold-tolerant microbes with warm-affinity ones, and alterations of microbial communities involved in soil biogeochemical processes. Soil and plant variables, such as above-ground biomass, soil pH, total phosphorus, and total potassium, well explained the variations in microbial communities, indicating that the coordinated changes in plant communities and soil properties during secondary succession caused accompanied shifts in microbial diversity and composition.
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Affiliation(s)
- Xiuping Liu
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
| | - Wangming Zhou
- School of Life Sciences, Anqing Normal University, Anqing, China
| | - Xinzhen Wang
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
| | - Hongliang Wu
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
| | - Wenxu Dong
- Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China
- *Correspondence: Wenxu Dong,
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14
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Ernakovich JG, Barbato RA, Rich VI, Schädel C, Hewitt RE, Doherty SJ, Whalen E, Abbott BW, Barta J, Biasi C, Chabot CL, Hultman J, Knoblauch C, Vetter M, Leewis M, Liebner S, Mackelprang R, Onstott TC, Richter A, Schütte U, Siljanen HMP, Taş N, Timling I, Vishnivetskaya TA, Waldrop MP, Winkel M. Microbiome assembly in thawing permafrost and its feedbacks to climate. GLOBAL CHANGE BIOLOGY 2022; 28:5007-5026. [PMID: 35722720 PMCID: PMC9541943 DOI: 10.1111/gcb.16231] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/24/2022] [Indexed: 05/15/2023]
Abstract
The physical and chemical changes that accompany permafrost thaw directly influence the microbial communities that mediate the decomposition of formerly frozen organic matter, leading to uncertainty in permafrost-climate feedbacks. Although changes to microbial metabolism and community structure are documented following thaw, the generality of post-thaw assembly patterns across permafrost soils of the world remains uncertain, limiting our ability to predict biogeochemistry and microbial community responses to climate change. Based on our review of the Arctic microbiome, permafrost microbiology, and community ecology, we propose that Assembly Theory provides a framework to better understand thaw-mediated microbiome changes and the implications for community function and climate feedbacks. This framework posits that the prevalence of deterministic or stochastic processes indicates whether the community is well-suited to thrive in changing environmental conditions. We predict that on a short timescale and following high-disturbance thaw (e.g., thermokarst), stochasticity dominates post-thaw microbiome assembly, suggesting that functional predictions will be aided by detailed information about the microbiome. At a longer timescale and lower-intensity disturbance (e.g., active layer deepening), deterministic processes likely dominate, making environmental parameters sufficient for predicting function. We propose that the contribution of stochastic and deterministic processes to post-thaw microbiome assembly depends on the characteristics of the thaw disturbance, as well as characteristics of the microbial community, such as the ecological and phylogenetic breadth of functional guilds, their functional redundancy, and biotic interactions. These propagate across space and time, potentially providing a means for predicting the microbial forcing of greenhouse gas feedbacks to global climate change.
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Affiliation(s)
- Jessica G. Ernakovich
- Natural Resources and the EnvironmentUniversity of New HampshireDurhamNew HampshireUSA
- Molecular, Cellular and Biomedical SciencesUniversity of New HampshireDurhamNew HampshireUSA
- EMergent Ecosystem Response to ChanGE (EMERGE) Biology Integration Institute
| | - Robyn A. Barbato
- U.S. Army Cold Regions Research and Engineering LaboratoryHanoverNew HampshireUSA
| | - Virginia I. Rich
- EMergent Ecosystem Response to ChanGE (EMERGE) Biology Integration Institute
- Microbiology DepartmentOhio State UniversityColumbusOhioUSA
- Byrd Polar and Climate Research CenterOhio State UniversityColombusOhioUSA
- Center of Microbiome ScienceOhio State UniversityColombusOhioUSA
| | - Christina Schädel
- Center for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Rebecca E. Hewitt
- Center for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
- Department of Environmental StudiesAmherst CollegeAmherstMassachusettsUSA
| | - Stacey J. Doherty
- Molecular, Cellular and Biomedical SciencesUniversity of New HampshireDurhamNew HampshireUSA
- U.S. Army Cold Regions Research and Engineering LaboratoryHanoverNew HampshireUSA
| | - Emily D. Whalen
- Natural Resources and the EnvironmentUniversity of New HampshireDurhamNew HampshireUSA
| | - Benjamin W. Abbott
- Department of Plant and Wildlife SciencesBrigham Young UniversityProvoUtahUSA
| | - Jiri Barta
- Centre for Polar EcologyUniversity of South BohemiaCeske BudejoviceCzech Republic
| | - Christina Biasi
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandKuopioFinland
| | - Chris L. Chabot
- California State University NorthridgeNorthridgeCaliforniaUSA
| | | | - Christian Knoblauch
- Institute of Soil ScienceUniversität HamburgHamburgGermany
- Center for Earth System Research and SustainabilityUniversität HamburgHamburgGermany
| | - Maggie C. Y. Lau Vetter
- Department of GeosciencesPrinceton UniversityPrincetonNew JerseyUSA
- Laboratory of Extraterrestrial Ocean Systems (LEOS)Institute of Deep‐sea Science and EngineeringChinese Academy of SciencesSanyaChina
| | - Mary‐Cathrine Leewis
- U.S. Geological Survey, GeologyMinerals, Energy and Geophysics Science CenterMenlo ParkCaliforniaUSA
- Agriculture and Agri‐Food CanadaQuebec Research and Development CentreQuebecQuebecCanada
| | - Susanne Liebner
- GFZ German Research Centre for GeosciencesSection GeomicrobiologyPotsdamGermany
| | | | | | - Andreas Richter
- Centre for Microbiology and Environmental Systems ScienceUniversity of ViennaViennaAustria
- Austrian Polar Research InstituteViennaAustria
| | | | - Henri M. P. Siljanen
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandKuopioFinland
| | - Neslihan Taş
- Lawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | | | - Tatiana A. Vishnivetskaya
- University of TennesseeKnoxvilleTennesseeUSA
- Institute of Physicochemical and Biological Problems of Soil SciencePushchinoRussia
| | - Mark P. Waldrop
- U.S. Geological Survey, GeologyMinerals, Energy and Geophysics Science CenterMenlo ParkCaliforniaUSA
| | - Matthias Winkel
- GFZ German Research Centre for GeosciencesInterface GeochemistryPotsdamGermany
- BfR Federal Institute for Risk AssessmentBerlinGermany
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15
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Nelson AR, Narrowe AB, Rhoades CC, Fegel TS, Daly RA, Roth HK, Chu RK, Amundson KK, Young RB, Steindorff AS, Mondo SJ, Grigoriev IV, Salamov A, Borch T, Wilkins MJ. Wildfire-dependent changes in soil microbiome diversity and function. Nat Microbiol 2022; 7:1419-1430. [PMID: 36008619 PMCID: PMC9418001 DOI: 10.1038/s41564-022-01203-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 07/18/2022] [Indexed: 12/13/2022]
Abstract
Forest soil microbiomes have crucial roles in carbon storage, biogeochemical cycling and rhizosphere processes. Wildfire season length, and the frequency and size of severe fires have increased owing to climate change. Fires affect ecosystem recovery and modify soil microbiomes and microbially mediated biogeochemical processes. To study wildfire-dependent changes in soil microbiomes, we characterized functional shifts in the soil microbiota (bacteria, fungi and viruses) across burn severity gradients (low, moderate and high severity) 1 yr post fire in coniferous forests in Colorado and Wyoming, USA. We found severity-dependent increases of Actinobacteria encoding genes for heat resistance, fast growth, and pyrogenic carbon utilization that might enhance post-fire survival. We report that increased burn severity led to the loss of ectomycorrhizal fungi and less tolerant microbial taxa. Viruses remained active in post-fire soils and probably influenced carbon cycling and biogeochemistry via turnover of biomass and ecosystem-relevant auxiliary metabolic genes. Our genome-resolved analyses link post-fire soil microbial taxonomy to functions and reveal the complexity of post-fire soil microbiome activity.
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Affiliation(s)
- Amelia R Nelson
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Adrienne B Narrowe
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
- Eastern Regional Research Center, Agricultural Research Service, Wyndmoor, PA, USA
| | - Charles C Rhoades
- Rocky Mountain Research Station, U.S. Forest Service, Fort Collins, CO, USA
| | - Timothy S Fegel
- Rocky Mountain Research Station, U.S. Forest Service, Fort Collins, CO, USA
| | - Rebecca A Daly
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Holly K Roth
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Rosalie K Chu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kaela K Amundson
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Robert B Young
- Chemical Analysis and Instrumentation Laboratory, New Mexico State University, Las Cruces, NM, USA
| | - Andrei S Steindorff
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Stephen J Mondo
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
| | - Igor V Grigoriev
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Asaf Salamov
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Thomas Borch
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO, USA
| | - Michael J Wilkins
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA.
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16
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Song W, Wang J, Hou L. Effects of frequency and amount of stover mulching on soil nitrogen and the microbial functional guilds of the endosphere and rhizosphere. Front Microbiol 2022; 13:976154. [PMID: 36090112 PMCID: PMC9449521 DOI: 10.3389/fmicb.2022.976154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/05/2022] [Indexed: 11/20/2022] Open
Abstract
Stover mulching as a conservation and sustainable agricultural practice is beneficial for maintaining soil nitrogen (N) requirements and plant health. The microbial functional guilds of the root and rhizosphere are important factors in the soil nitrogen cycle. However, it is unclear how the frequency and amount of stover mulching influence microbial functional guilds in the root and rhizosphere. Therefore, we investigated the responses of the microbial functional guilds in the endosphere and rhizosphere to maize stover mulching amounts (0, 1/3, 2/3, and total stover mulching every year) and frequencies (once every 3 years and twice every 3 years) under 10-year no-till management. The bacterial functional guilds of nitrogen fixation, nitrification, and anaerobic nitrate oxidation displayed the significantly correlation with C/N, total nitrogen, NO3−, and NH4+. The fungal functional guilds of plant pathogens and saprotrophs showed significantly correlations with C/N, total nitrogen, and NO3−. Moreover, we found that bacterial guilds play a pivotal role in maintaining N requirements at the jointing stage, whereas root endophytic fungal guilds play a more important role than bacterial guilds in regulating plant health at the mature stage. The frequency and amount of stover mulching had significant effects on the microbial functional guilds in the root and rhizosphere. Our data suggest that stover mulch application twice every 3 years is the optimal mulching frequency because it yielded the lowest abundance of nitrifying and anaerobic nitrate-oxidising bacteria and the highest abundance of nitrogen-fixing bacteria at the jointing stage, as well as the lowest abundance of fungal plant pathogens in roots at the mature stage.
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Affiliation(s)
- Wenchen Song
- Key Laboratory of Ecology and Environment in Minority Areas, Minzu University of China, National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- *Correspondence: Wenchen Song,
| | - Jing Wang
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Lei Hou
- Beijing Pollution Source Related Affair Management Center, Beijing, China
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17
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Bonanomi G, Idbella M, Abd-ElGawad AM, Motti R, Ippolito F, Santorufo L, Adamo P, Agrelli D, De Marco A, Maisto G, Zotti M. Impact of prescribed burning, mowing and abandonment on a Mediterranean grassland: A 5-year multi-kingdom comparison. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155442. [PMID: 35469869 DOI: 10.1016/j.scitotenv.2022.155442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 03/20/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Mediterranean grasslands are semi-natural, fire-prone, species-rich ecosystems that have been maintained for centuries through a combination of fire, grazing, and mowing. Over the past half century, however, grasslands have faced numerous threats, including the abandonment of traditional agro-pastoral practices. Our hypothesis was that mowing and prescribed burning are management practices potentially effective in counteracting the reduction of plant diversity triggered by land abandonment. However, the long-term effects of such management practices on plant communities and soil microbiota in Mediterranean grassland remain poorly studied. Here, we conducted a 5-year field experiment comparing prescribed fire, vegetation mowing, and abandonment in a fire-prone Mediterranean grassland in southern Italy in order to evaluate the capability of such management strategies to counteract the detrimental impacts of land abandonment on plant diversity and the associated increase of wildfire. We combined vegetation analysis and soil chemical characterization and several microbiota analyses, including microbial biomass and respiration, arthropod community, and high-throughput sequencing of bacterial and eukaryotic rRNA gene markers. Burning and mowing significantly increased plant species richness and diversity compared to abandonment plots, reducing the abundance of perennial tall grasses in favour of short-lived species. Standing litter followed the same trend, being 3.8-fold greater and largely composed of grass remains in the abandoned compared to burnt and mowed plots. In the soil, prescribed burning caused significant increase in pH, a reduction in organic carbon, total N, and cation exchange capacity. Diversity and taxonomic composition of bacterial and fungal microbiota was affected by burning and mowing treatments. Abandonment caused shifts of microbiota towards a fungal-dominated system, composed of late successional fungi of the Basidiomycota. Fast-growing and putative fungal pathogens were more abundant under burnt and mowed treatments. Soil arthropods were influenced by vegetation and microbiota changes, being strongly reduced in mowed plots. Our study demonstrated that grassland abandonment promotes the spread of tall grasses, reducing plant diversity and increasing the risk of wildfire, while prescribed burning and mowing are effective in counteracting such negative effects.
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Affiliation(s)
- Giuliano Bonanomi
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy; Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy; Cicerale Research Center, Cicerale 84053, Campania region, Italy
| | - Mohamed Idbella
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy; Laboratory of Biosciences, Faculty of Sciences and Techniques, Hassan II University, Casablanca, Morocco; Cicerale Research Center, Cicerale 84053, Campania region, Italy.
| | - Ahmed M Abd-ElGawad
- Plant Production Department, College of Food & Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia; Department of Botany, Faculty of Sciences, Mansoura University, Mansoura, Egypt
| | - Riccardo Motti
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
| | - Francesca Ippolito
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
| | - Lucia Santorufo
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, via Cinthia ed. 7, 80126 Naples, Italy
| | - Paola Adamo
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
| | - Diana Agrelli
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
| | - Anna De Marco
- Department of Pharmacy, University of Naples Federico II, Via Montesano 49, 80131 Naples, Italy; Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
| | - Giulia Maisto
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, via Cinthia ed. 7, 80126 Naples, Italy; Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
| | - Maurizio Zotti
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
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18
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Microbiogeochemical Traits to Identify Nitrogen Hotspots in Permafrost Regions. NITROGEN 2022. [DOI: 10.3390/nitrogen3030031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Permafrost-affected tundra soils are large carbon (C) and nitrogen (N) reservoirs. However, N is largely bound in soil organic matter (SOM), and ecosystems generally have low N availability. Therefore, microbial induced N-cycling processes and N losses were considered negligible. Recent studies show that microbial N processing rates, inorganic N availability, and lateral N losses from thawing permafrost increase when vegetation cover is disturbed, resulting in reduced N uptake or increased N input from thawing permafrost. In this review, we describe currently known N hotspots, particularly bare patches in permafrost peatland or permafrost soils affected by thermokarst, and their microbiogeochemical characteristics, and present evidence for previously unrecorded N hotspots in the tundra. We summarize the current understanding of microbial N cycling processes that promote the release of the potent greenhouse gas (GHG) nitrous oxide (N2O) and the translocation of inorganic N from terrestrial into aquatic ecosystems. We suggest that certain soil characteristics and microbial traits can be used as indicators of N availability and N losses. Identifying N hotspots in permafrost soils is key to assessing the potential for N release from permafrost-affected soils under global warming, as well as the impact of increased N availability on emissions of carbon-containing GHGs.
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19
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Honeyman AS, Fegel TS, Peel HF, Masters NA, Vuono DC, Kleiber W, Rhoades CC, Spear JR. Statistical Learning and Uncommon Soil Microbiota Explain Biogeochemical Responses after Wildfire. Appl Environ Microbiol 2022; 88:e0034322. [PMID: 35703548 PMCID: PMC9275219 DOI: 10.1128/aem.00343-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/16/2022] [Indexed: 11/20/2022] Open
Abstract
Wildfires are a perennial event globally, and the biogeochemical underpinnings of soil responses at relevant spatial and temporal scales are unclear. Soil biogeochemical processes regulate plant growth and nutrient losses that affect water quality, yet the response of soil after variable intensity fire is difficult to explain and predict. To address this issue, we examined two wildfires in Colorado, United States, across the first and second postfire years and leveraged statistical learning (SL) to predict and explain biogeochemical responses. We found that SL predicts biogeochemical responses in soil after wildfire with surprising accuracy. Of the 13 biogeochemical analytes analyzed in this study, 9 are best explained with a hybrid microbiome + biogeochemical SL model. Biogeochemical-only models best explain 3 features, and 1 feature is explained equally well with the hybrid and biogeochemical-only models. In some cases, microbiome-only SL models are also effective (such as predicting NH4+). Whenever a microbiome component is employed, selected features always involve uncommon soil microbiota (i.e., the "rare biosphere" [existing at <1% mean relative abundance]). Here, we demonstrate that SL paired with DNA sequence and biogeochemical data predicts environmental features in postfire soils, although this approach could likely be applied to any biogeochemical system. IMPORTANCE Soil biogeochemical processes are critical to plant growth and water quality and are substantially disturbed by wildfire. However, soil responses to fire are difficult to predict. To address this issue, we developed a large environmental data set that tracks postfire changes in soil and used statistical learning (SL) to build models that exploit complex data to make predictions about biogeochemical responses. Here, we show that SL depends upon uncommon microbiota in soil (the "rare biosphere") to make surprisingly accurate predictions about soil biogeochemical responses to wildfire. Using SL to explain variation in a natively chaotic environmental system is mechanism independent. Likely, the approach that we describe for combining SL with microbiome and biogeochemical parameters has practical applications across a range of issues in the environmental sciences where predicting responses would be useful.
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Affiliation(s)
- Alexander S. Honeyman
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - Timothy S. Fegel
- Rocky Mountain Research Station, USDA Forest Service, Fort Collins, Colorado, USA
| | - Henry F. Peel
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - Nicole A. Masters
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - David C. Vuono
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - William Kleiber
- Applied Mathematics, University of Colorado, Boulder, Colorado, USA
| | - Charles C. Rhoades
- Rocky Mountain Research Station, USDA Forest Service, Fort Collins, Colorado, USA
| | - John R. Spear
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado, USA
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20
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Ecological and genomic responses of soil microbiomes to high-severity wildfire: linking community assembly to functional potential. THE ISME JOURNAL 2022; 16:1853-1863. [PMID: 35430593 PMCID: PMC9213548 DOI: 10.1038/s41396-022-01232-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/06/2022] [Accepted: 03/28/2022] [Indexed: 12/14/2022]
Abstract
Increasing wildfire severity, which is common throughout the western United States, can have deleterious effects on plant regeneration and large impacts on carbon (C) and nitrogen (N) cycling rates. Soil microbes are pivotal in facilitating these elemental cycles, so understanding the impact of increasing fire severity on soil microbial communities is critical. Here, we assess the long-term impact of high-severity fires on the soil microbiome. We find that high-severity wildfires result in a multi-decadal (>25 y) recovery of the soil microbiome mediated by concomitant differences in aboveground vegetation, soil chemistry, and microbial assembly processes. Our results depict a distinct taxonomic and functional successional pattern of increasing selection in post-fire soil microbial communities. Changes in microbiome composition corresponded with changes in microbial functional potential, specifically altered C metabolism and enhanced N cycling potential, which related to rates of potential decomposition and inorganic N availability, respectively. Based on metagenome-assembled genomes, we show that bacterial genomes enriched in our earliest site (4 y since fire) harbor distinct traits such as a robust stress response and a high potential to degrade pyrogenic, polyaromatic C that allow them to thrive in post-fire environments. Taken together, these results provide a biological basis for previously reported process rate measurements and explain the temporal dynamics of post-fire biogeochemistry, which ultimately constrains ecosystem recovery.
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21
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Xu W, Elberling B, Ambus PL. Fire increases soil nitrogen retention and alters nitrogen uptake patterns among dominant shrub species in an Arctic dry heath tundra. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150990. [PMID: 34656575 DOI: 10.1016/j.scitotenv.2021.150990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Climate change increases the frequency and severity of fire in the Arctic tundra regions. We assessed effects of fire in combination with summer warming on soil biogeochemical N- and P cycles with a focus on mineral N over two years following an experimental fire in a dry heath tundra, West Greenland. We applied stable isotopes (15NH4+-N and 15NO3--N) to trace the post-fire mineral N pools. The partitioning of 15N in the bulk soils, soil dissolved organic N (TDN), microbes and plants (roots and leaves) was established. The fire tended to increase microbial P pools by four-fold at both one and two years after the fire. Two years after the fire, the bulk soil 15N recovery has decreased to 10.4% in unburned plots while relatively high recovery was maintained (30%) in burned plots, suggesting an increase in soil N retention after the fire. The contribution of microbial 15N recovery to bulk soil 15N recovery increased from 11.2% at 21 days to 31.5% two years after the fire, suggesting that higher post-fire N retention was due largely to the increased incorporation of N into microbial biomass. Fire also increased 15N recovery in bulk roots after one and two years, but only under summer warming. This suggests that higher retention of post-fire N can strongly increase the potential for N uptake of recovering plants under a future warmer climate. There was significantly lower 15N enrichment of Betula nana leaves while higher 15N enrichment of Vaccinium uliginosum leaves (after three years) in burned than control plots. This shows that fire can alter the N uptake differently among dominant shrub species in this tundra ecosystem, and implies that wildfires may change plant species composition in the longer term.
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Affiliation(s)
- Wenyi Xu
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark.
| | - Bo Elberling
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Per Lennart Ambus
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
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22
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Su WQ, Tang C, Lin J, Yu M, Dai Z, Luo Y, Li Y, Xu J. Recovery patterns of soil bacterial and fungal communities in Chinese boreal forests along a fire chronosequence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:150372. [PMID: 34818758 DOI: 10.1016/j.scitotenv.2021.150372] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/11/2021] [Accepted: 09/12/2021] [Indexed: 05/17/2023]
Abstract
Wildfire has profound and pervasive consequences for forest ecosystems via directly altering soil physicochemical properties and modulating microbial community. In this study, we examined the changes in soil properties and microbial community composition and structure at different periods after highly severe wildfire events (44 plots, 113 samples) in the Chinese Great Khingan Mountains. We also separated charcoal from burnt soils to establish the relationship between microbial community structures in soils and charcoal. We found that wildfire only significantly altered bacterial and fungal β-diversity, but had no effect on microbial α-diversity across a 29-year chronosequence. The network analysis revealed that the complexity and connectivity of bacterial and fungal communities were significantly increased from 17 years after fire, compared with either unburnt soils or soils with recent fires (0-4 years after fire). Differential abundance analysis suggested that bacterial and fungal OTUs were enriched or depleted only during 0-4 years after fire compared with the unburnt soils. In addition, soil pH, dissolved organic C and dissolved organic N were key determinants of soil bacterial and fungal communities during 17-29 years after fire. The fire-derived charcoal provided a new niche for microbial colonization, and microbes colonized in the charcoal had a significantly different community structure from those of burnt soils. Our data suggest that soil bacterial and fungal communities changed significantly during the recovery from fire events in terms of the abundance and co-occurrence networks in the boreal forest ecosystems.
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Affiliation(s)
- Wei-Qin Su
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Caixian Tang
- Department of Animal, Plant and Soil Sciences, La Trobe University, Melbourne Campus, Bundoora, VIC 3086, Australia
| | - Jiahui Lin
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Mengjie Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Zhongmin Dai
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yu Luo
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yong Li
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Jianming Xu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China.
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23
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Wu L, Yang F, Feng J, Tao X, Qi Q, Wang C, Schuur EAG, Bracho R, Huang Y, Cole JR, Tiedje JM, Zhou J. Permafrost thaw with warming reduces microbial metabolic capacities in subsurface soils. Mol Ecol 2021; 31:1403-1415. [PMID: 34878672 DOI: 10.1111/mec.16319] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/04/2021] [Accepted: 12/01/2021] [Indexed: 01/27/2023]
Abstract
Microorganisms are major constituents of the total biomass in permafrost regions, whose underlain soils are frozen for at least two consecutive years. To understand potential microbial responses to climate change, here we examined microbial community compositions and functional capacities across four soil depths in an Alaska tundra site. We showed that a 5-year warming treatment increased soil thaw depth by 25.7% (p = .011) within the deep organic layer (15-25 cm). Concurrently, warming reduced 37% of bacterial abundance and 64% of fungal abundances in the deep organic layer, while it did not affect microbial abundance in other soil layers (i.e., 0-5, 5-15, and 45-55 cm). Warming treatment altered fungal community composition and microbial functional structure (p < .050), but not bacterial community composition. Using a functional gene array, we found that the relative abundances of a variety of carbon (C)-decomposing, iron-reducing, and sulphate-reducing genes in the deep organic layer were decreased, which was not observed by the shotgun sequencing-based metagenomics analysis of those samples. To explain the reduced metabolic capacities, we found that warming treatment elicited higher deterministic environmental filtering, which could be linked to water-saturated time, soil moisture, and soil thaw duration. In contrast, plant factors showed little influence on microbial communities in subsurface soils below 15 cm, despite a 25.2% higher (p < .05) aboveground plant biomass by warming treatment. Collectively, we demonstrate that microbial metabolic capacities in subsurface soils are reduced, probably arising from enhanced thaw by warming.
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Affiliation(s)
- Linwei Wu
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Felix Yang
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Jiajie Feng
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Xuanyu Tao
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Qi Qi
- School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing, China
| | - Cong Wang
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | - Rosvel Bracho
- Department of Biology, School of Forest Resources and Conservation, University of Florida, Gainesville, Florida, USA
| | - Yi Huang
- College of Environmental Science and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing, China
| | - James R Cole
- Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, USA
| | - James M Tiedje
- Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, USA
| | - Jizhong Zhou
- Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA.,Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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24
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Xu W, Lambæk A, Holm SS, Furbo-Halken A, Elberling B, Ambus PL. Effects of experimental fire in combination with climate warming on greenhouse gas fluxes in Arctic tundra soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148847. [PMID: 34246149 DOI: 10.1016/j.scitotenv.2021.148847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
The frequency and severity of fire is increasing in Arctic tundra regions with climate change. Here we investigated effects of experimental low-intensity fire and shrub cutting, in combination with warming, on soil biogeochemical cycles and post-fire greenhouse gas (GHG) emissions in a dry heath tundra, West Greenland. We performed in vitro incubation experiments based on soil samples collected for up to two years after the fire. We observed tendency for increased soil nitrate (14-fold) and significant increases in soil ammonium and phosphate (four-fold and five-fold, respectively) two years after the fire, but no effects of shrub cutting on these compounds. Thus, changes appear to be largely due to fire effects rather than indirect effects by vegetation destruction. Two years after fire, nitrous oxide (N2O) and carbon dioxide (CO2) production was significantly increased (three-fold and 32% higher, respectively), in burned than unburned soils, while methane (CH4) uptake remained unchanged. This stimulated N2O and CO2 production by the fire, however, was only apparent under conditions when soil was at maximum water holding capacity, suggesting that fire effects can be masked under dry conditions in this tundra ecosystem. There were positive effects by modest 2.5 °C warming on CO2 production in control but not in burned soils, suggesting that fire may decrease the temperature response in soil respiration. Methane uptake was neither altered by the modest warming in shrub-cut nor in burned soils after two years, suggesting that the removal of vegetation may play a key role in controlling future temperature response of CH4 oxidation. Altogether, our results show that post-fire tundra soils have the potential to enhance soil GHG emissions (e.g. N2O and CO2) especially during episodes with wet soil conditions. On the other hand, the lack of warming responses in post-fire soil respiration may weaken this positive feedback to climate change.
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Affiliation(s)
- Wenyi Xu
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark.
| | - Anders Lambæk
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Signe Skjold Holm
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Annesofie Furbo-Halken
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Bo Elberling
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Per Lennart Ambus
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark
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25
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Chen Y, Liu F, Kang L, Zhang D, Kou D, Mao C, Qin S, Zhang Q, Yang Y. Large-scale evidence for microbial response and associated carbon release after permafrost thaw. GLOBAL CHANGE BIOLOGY 2021; 27:3218-3229. [PMID: 33336478 DOI: 10.1111/gcb.15487] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
Permafrost thaw could trigger the release of greenhouse gases through microbial decomposition of the large quantities of carbon (C) stored within frozen soils. However, accurate evaluation of soil C emissions from thawing permafrost is still a big challenge, partly due to our inadequate understanding about the response of microbial communities and their linkage with soil C release upon permafrost thaw. Based on a large-scale permafrost sampling across 24 sites on the Tibetan Plateau, we employed meta-genomic technologies (GeoChip and Illumina MiSeq sequencing) to explore the impacts of permafrost thaw (permafrost samples were incubated for 11 days at 5°C) on microbial taxonomic and functional communities, and then conducted a laboratory incubation to investigate the linkage of microbial taxonomic and functional diversity with soil C release after permafrost thaw. We found that bacterial and fungal α diversity decreased, but functional gene diversity and the normalized relative abundance of C degradation genes increased after permafrost thaw, reflecting the rapid microbial response to permafrost thaw. Moreover, both the microbial taxonomic and functional community structures differed between the thawed permafrost and formerly frozen soils. Furthermore, soil C release rate over five month incubation was associated with microbial functional diversity and C degradation gene abundances. By contrast, neither microbial taxonomic diversity nor community structure exhibited any significant effects on soil C release over the incubation period. These findings demonstrate that permafrost thaw could accelerate C emissions by altering the function potentials of microbial communities rather than taxonomic diversity, highlighting the crucial role of microbial functional genes in mediating the responses of permafrost C cycle to climate warming.
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Affiliation(s)
- Yongliang Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Futing Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Luyao Kang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dianye Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Dan Kou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Chao Mao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shuqi Qin
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiwen Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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26
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Habitat heterogeneity induced by pyrogenic organic matter in wildfire-perturbed soils mediates bacterial community assembly processes. THE ISME JOURNAL 2021; 15:1943-1955. [PMID: 33514880 PMCID: PMC8245576 DOI: 10.1038/s41396-021-00896-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 12/16/2020] [Accepted: 01/14/2021] [Indexed: 01/30/2023]
Abstract
Although pyrogenic organic matter (PyOM) generated during wildfires plays a critical role in post-fire ecosystem recovery, the specific mechanisms by which PyOM controls soil microbial community assembly after wildfire perturbation remain largely uncharacterized. Herein we characterized the effect of PyOM on soil bacterial communities at two independent wildfire-perturbed forest sites. We observed that α-diversity of bacterial communities was the highest in wildfire-perturbed soils and that bacterial communities gradually changed along a sequence of unburnt soil → burnt soil → PyOM. The microbial communities reconstructed from unburnt soil and PyOM resembled the real bacterial communities in wildfire-perturbed soils in their α-diversity and community structure. Bacterial specialists in PyOM and soils clustered in phylogenetic coherent lineages with intra-lineage pH-niche conservatism and inter-lineage pH-niche divergence. Our results suggest that PyOM mediates bacterial community assembly in wildfire-perturbed soils by a combination of environmental selection and dispersal of phylogenetic coherent specialists with habitat preference in the heterogeneous microhabitats of burnt soils with distinct PyOM patches.
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27
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Montgomery K, Williams TJ, Brettle M, Berengut JF, Zhang E, Zaugg J, Hugenholtz P, Ferrari BC. Persistence and resistance: survival mechanisms of Candidatus Dormibacterota from nutrient-poor Antarctic soils. Environ Microbiol 2021; 23:4276-4294. [PMID: 34029441 DOI: 10.1111/1462-2920.15610] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/28/2022]
Abstract
Candidatus Dormibacterota is an uncultured bacterial phylum found predominantly in soil that is present in high abundances within cold desert soils. Here, we interrogate nine metagenome-assembled genomes (MAGs), including six new MAGs derived from soil metagenomes obtained from two eastern Antarctic sites. Phylogenomic and taxonomic analyses revealed these MAGs represent four genera and five species, representing two order-level clades within Ca. Dormibacterota. Metabolic reconstructions of these MAGs revealed the potential for aerobic metabolism, and versatile adaptations enabling persistence in the 'extreme' Antarctic environment. Primary amongst these adaptations were abilities to scavenge atmospheric H2 and CO as energy sources, as well as using the energy derived from H2 oxidation to fix atmospheric CO2 via the Calvin-Bassham-Benson cycle, using a RuBisCO type IE. We propose that these allow Ca. Dormibacterota to persist using H2 oxidation and grow using atmospheric chemosynthesis in terrestrial Antarctica. Fluorescence in situ hybridization revealed Ca. Dormibacterota to be coccoid cells, 0.3-1.4 μm in diameter, with some cells exhibiting the potential for a symbiotic or syntrophic lifestyle.
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Affiliation(s)
- Kate Montgomery
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Randwick, NSW, 2052, Australia
| | - Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Randwick, NSW, 2052, Australia
| | - Merryn Brettle
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, UNSW Sydney, Randwick, NSW, 2052, Australia
| | - Jonathan F Berengut
- EMBL Australia Node for Single Molecule Science, School of Medical Sciences, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Eden Zhang
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Randwick, NSW, 2052, Australia
| | - Julian Zaugg
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Belinda C Ferrari
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Randwick, NSW, 2052, Australia
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28
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Dove NC, Klingeman DM, Carrell AA, Cregger MA, Schadt CW. Fire alters plant microbiome assembly patterns: integrating the plant and soil microbial response to disturbance. THE NEW PHYTOLOGIST 2021; 230:2433-2446. [PMID: 33525047 PMCID: PMC8251558 DOI: 10.1111/nph.17248] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/27/2021] [Indexed: 05/06/2023]
Abstract
It is increasingly evident that the plant microbiome is a strong determinant of plant health. While the ability to manipulate the microbiome in plants and ecosystems recovering from disturbance may be useful, our understanding of the plant microbiome in regenerating plant communities is currently limited. Using 16S ribosomal RNA (rRNA) gene and internal transcribed spacer (ITS) region amplicon sequencing, we characterized the leaf, stem, fine root, rhizome, and rhizosphere microbiome of < 1-yr-old aspen saplings and the associated bulk soil after a recent high-intensity prescribed fire across a burn severity gradient. Consistent with previous studies, we found that soil microbiomes are responsive to fire. We extend these findings by showing that certain plant tissue microbiomes also change in response to fire. Differences in soil microbiome compositions could be attributed to soil chemical characteristics, but, generally, plant tissue microbiomes were not related to plant tissue elemental concentrations. Using source tracking modeling, we also show that fire influences the relative dominance of microbial inoculum and the vertical inheritance of the sapling microbiome from the parent tree. Overall, our results demonstrate how fire impacts plant microbiome assembly, diversity, and composition and highlights potential for further research towards increasing plant fitness and ecosystem recovery after fire events.
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Affiliation(s)
- Nicholas C. Dove
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Dawn M. Klingeman
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Alyssa A. Carrell
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Melissa A. Cregger
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTN37996USA
| | - Christopher W. Schadt
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of MicrobiologyUniversity of TennesseeKnoxvilleTN37996USA
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29
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North American boreal forests are a large carbon source due to wildfires from 1986 to 2016. Sci Rep 2021; 11:7723. [PMID: 33833331 PMCID: PMC8032736 DOI: 10.1038/s41598-021-87343-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/24/2021] [Indexed: 11/08/2022] Open
Abstract
Wildfires are a major disturbance to forest carbon (C) balance through both immediate combustion emissions and post-fire ecosystem dynamics. Here we used a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to simulate C budget in Alaska and Canada during 1986-2016, as impacted by fire disturbances. We extracted the data of difference Normalized Burn Ratio (dNBR) for fires from Landsat TM/ETM imagery and estimated the proportion of vegetation and soil C combustion. We observed that the region was a C source of 2.74 Pg C during the 31-year period. The observed C loss, 57.1 Tg C year-1, was attributed to fire emissions, overwhelming the net ecosystem production (1.9 Tg C year-1) in the region. Our simulated direct emissions for Alaska and Canada are within the range of field measurements and other model estimates. As burn severity increased, combustion emission tended to switch from vegetation origin towards soil origin. When dNBR is below 300, fires increase soil temperature and decrease soil moisture and thus, enhance soil respiration. However, the post-fire soil respiration decreases for moderate or high burn severity. The proportion of post-fire soil emission in total emissions increased with burn severity. Net nitrogen mineralization gradually recovered after fire, enhancing net primary production. Net ecosystem production recovered fast under higher burn severities. The impact of fire disturbance on the C balance of northern ecosystems and the associated uncertainties can be better characterized with long-term, prior-, during- and post-disturbance data across the geospatial spectrum. Our findings suggest that the regional source of carbon to the atmosphere will persist if the observed forest wildfire occurrence and severity continues into the future.
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Metabolic capabilities mute positive response to direct and indirect impacts of warming throughout the soil profile. Nat Commun 2021; 12:2089. [PMID: 33828081 PMCID: PMC8027381 DOI: 10.1038/s41467-021-22408-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
Increasing global temperatures are predicted to stimulate soil microbial respiration. The direct and indirect impacts of warming on soil microbes, nevertheless, remain unclear. This is particularly true for understudied subsoil microbes. Here, we show that 4.5 years of whole-profile soil warming in a temperate mixed forest results in altered microbial community composition and metabolism in surface soils, partly due to carbon limitation. However, microbial communities in the subsoil responded differently to warming than in the surface. Throughout the soil profile-but to a greater extent in the subsoil-physiologic and genomic measurements show that phylogenetically different microbes could utilize complex organic compounds, dampening the effect of altered resource availability induced by warming. We find subsoil microbes had 20% lower carbon use efficiencies and 47% lower growth rates compared to surface soils, which constrain microbial communities. Collectively, our results show that unlike in surface soils, elevated microbial respiration in subsoils may continue without microbial community change in the near-term.
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Mehta S, Crane M, Leith E, Batut B, Hiltemann S, Arntzen MØ, Kunath BJ, Pope PB, Delogu F, Sajulga R, Kumar P, Johnson JE, Griffin TJ, Jagtap PD. ASaiM-MT: a validated and optimized ASaiM workflow for metatranscriptomics analysis within Galaxy framework. F1000Res 2021; 10:103. [PMID: 34484688 PMCID: PMC8383124 DOI: 10.12688/f1000research.28608.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
The Earth Microbiome Project (EMP) aided in understanding the role of microbial communities and the influence of collective genetic material (the 'microbiome') and microbial diversity patterns across the habitats of our planet. With the evolution of new sequencing technologies, researchers can now investigate the microbiome and map its influence on the environment and human health. Advances in bioinformatics methods for next-generation sequencing (NGS) data analysis have helped researchers to gain an in-depth knowledge about the taxonomic and genetic composition of microbial communities. Metagenomic-based methods have been the most commonly used approaches for microbiome analysis; however, it primarily extracts information about taxonomic composition and genetic potential of the microbiome under study, lacking quantification of the gene products (RNA and proteins). On the other hand, metatranscriptomics, the study of a microbial community's RNA expression, can reveal the dynamic gene expression of individual microbial populations and the community as a whole, ultimately providing information about the active pathways in the microbiome. In order to address the analysis of NGS data, the ASaiM analysis framework was previously developed and made available via the Galaxy platform. Although developed for both metagenomics and metatranscriptomics, the original publication demonstrated the use of ASaiM only for metagenomics, while thorough testing for metatranscriptomics data was lacking. In the current study, we have focused on validating and optimizing the tools within ASaiM for metatranscriptomics data. As a result, we deliver a robust workflow that will enable researchers to understand dynamic functional response of the microbiome in a wide variety of metatranscriptomics studies. This improved and optimized ASaiM-metatranscriptomics (ASaiM-MT) workflow is publicly available via the ASaiM framework, documented and supported with training material so that users can interrogate and characterize metatranscriptomic data, as part of larger meta-omic studies of microbiomes.
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Affiliation(s)
- Subina Mehta
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Marie Crane
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Emma Leith
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Bérénice Batut
- Department of Bioinformatics, University of Freiburg, Georges-Köhler-Allee 106, Freiburg, Germany
| | - Saskia Hiltemann
- Department of Pathology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | | | | | - Ray Sajulga
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Praveen Kumar
- University of Minnesota, Twin Cities, MN, 55455, USA
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Mehta S, Crane M, Leith E, Batut B, Hiltemann S, Arntzen MØ, Kunath BJ, Pope PB, Delogu F, Sajulga R, Kumar P, Johnson JE, Griffin TJ, Jagtap PD. ASaiM-MT: a validated and optimized ASaiM workflow for metatranscriptomics analysis within Galaxy framework. F1000Res 2021; 10:103. [PMID: 34484688 PMCID: PMC8383124 DOI: 10.12688/f1000research.28608.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/03/2021] [Indexed: 12/13/2022] Open
Abstract
The Human Microbiome Project (HMP) aided in understanding the role of microbial communities and the influence of collective genetic material (the 'microbiome') in human health and disease. With the evolution of new sequencing technologies, researchers can now investigate the microbiome and map its influence on human health. Advances in bioinformatics methods for next-generation sequencing (NGS) data analysis have helped researchers to gain an in-depth knowledge about the taxonomic and genetic composition of microbial communities. Metagenomic-based methods have been the most commonly used approaches for microbiome analysis; however, it primarily extracts information about taxonomic composition and genetic potential of the microbiome under study, lacking quantification of the gene products (RNA and proteins). Conversely, metatranscriptomics, the study of a microbial community's RNA expression, can reveal the dynamic gene expression of individual microbial populations and the community as a whole, ultimately providing information about the active pathways in the microbiome. In order to address the analysis of NGS data, the ASaiM analysis framework was previously developed and made available via the Galaxy platform. Although developed for both metagenomics and metatranscriptomics, the original publication demonstrated the use of ASaiM only for metagenomics, while thorough testing for metatranscriptomics data was lacking. In the current study, we have focused on validating and optimizing the tools within ASaiM for metatranscriptomics data. As a result, we deliver a robust workflow that will enable researchers to understand dynamic functional response of the microbiome in a wide variety of metatranscriptomics studies. This improved and optimized ASaiM-metatranscriptomics (ASaiM-MT) workflow is publicly available via the ASaiM framework, documented and supported with training material so that users can interrogate and characterize metatranscriptomic data, as part of larger meta-omic studies of microbiomes.
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Affiliation(s)
- Subina Mehta
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Marie Crane
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Emma Leith
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Bérénice Batut
- Department of Bioinformatics, University of Freiburg, Georges-Köhler-Allee 106, Freiburg, Germany
| | - Saskia Hiltemann
- Department of Pathology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | | | | | - Ray Sajulga
- University of Minnesota, Twin Cities, MN, 55455, USA
| | - Praveen Kumar
- University of Minnesota, Twin Cities, MN, 55455, USA
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Liu F, Kou D, Chen Y, Xue K, Ernakovich JG, Chen L, Yang G, Yang Y. Altered microbial structure and function after thermokarst formation. GLOBAL CHANGE BIOLOGY 2021; 27:823-835. [PMID: 33155741 DOI: 10.1111/gcb.15438] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/05/2020] [Indexed: 05/27/2023]
Abstract
Permafrost thaw could induce substantial carbon (C) emissions to the atmosphere, and thus trigger a positive feedback to climate warming. As the engine of biogeochemical cycling, soil microorganisms exert a critical role in mediating the direction and strength of permafrost C-climate feedback. However, our understanding about the impacts of thermokarst (abrupt permafrost thaw) on microbial structure and function remains limited. Here we employed metagenomic sequencing to analyze changes in topsoil (0-15 cm) microbial communities and functional genes along a permafrost thaw sequence (1, 10, and 16 years since permafrost collapse) on the Tibetan Plateau. By combining laboratory incubation and a two-pool model, we then explored changes in soil labile and stable C decomposition along the thaw sequence. Our results showed that topsoil microbial α-diversity decreased, while the community structure and functional gene abundance did not exhibit any significant change at the early stage of collapse (1 year since collapse) relative to non-collapsed control. However, as the time since the collapse increased, both the topsoil microbial community structure and functional genes differed from the control. Abundances of functional genes involved in labile C degradation decreased while those for stable C degradation increased at the late stage of collapse (16 years since collapse), largely driven by changes in substrate properties along the thaw sequence. Accordingly, faster stable C decomposition occurred at the late stage of collapse compared to the control, which was associated with the increase in relative abundance of functional genes for stable C degradation. These results suggest that upland thermokarst alters microbial structure and function, particularly enhances soil stable C decomposition by modulating microbial functional genes, which could reinforce a warmer climate over the decadal timescale.
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Affiliation(s)
- Futing Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Dan Kou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Yongliang Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Kai Xue
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Jessica G Ernakovich
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
| | - Leiyi Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guibiao Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
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Flanagan NE, Wang H, Winton S, Richardson CJ. Low-severity fire as a mechanism of organic matter protection in global peatlands: Thermal alteration slows decomposition. GLOBAL CHANGE BIOLOGY 2020; 26:3930-3946. [PMID: 32388914 DOI: 10.1111/gcb.15102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/19/2020] [Accepted: 03/08/2020] [Indexed: 05/16/2023]
Abstract
Worldwide, regularly recurring wildfires shape many peatland ecosystems to the extent that fire-adapted species often dominate plant communities, suggesting that wildfire is an integral part of peatland ecology rather than an anomaly. The most destructive blazes are smoldering fires that are usually initiated in periods of drought and can combust entire peatland carbon stores. However, peatland wildfires more typically occur as low-severity surface burns that arise in the dormant season when vegetation is desiccated, and soil moisture is high. In such low-severity fires, surface layers experience flash heating, but there is little loss of underlying peat to combustion. This study examines the potential importance of such processes in several peatlands that span a gradient from hemiboreal to tropical ecozones and experience a wide range of fire return intervals. We show that low-severity fires can increase the pool of stable soil carbon by thermally altering the chemistry of soil organic matter (SOM), thereby reducing rates of microbial respiration. Using X-ray photoelectron spectroscopy and Fourier transform infrared, we demonstrate that low-severity fires significantly increase the degree of carbon condensation and aromatization of SOM functional groups, particularly on the surface of peat aggregates. Laboratory incubations show lower CO2 emissions from peat subjected to low-severity fire and predict lower cumulative CO2 emissions from burned peat after 1-3 years. Also, low-severity fires reduce the temperature sensitivity (Q10 ) of peat, indicating that these fires can inhibit microbial access to SOM. The increased stability of thermally altered SOM may allow a greater proportion of organic matter to survive vertical migration into saturated and anaerobic zones of peatlands where environmental conditions physiochemically protect carbon stores from decomposition for thousands of years. Thus, across latitudes, low-severity fire is an overlooked factor influencing carbon cycling in peatlands, which is relevant to global carbon budgets as climate change alters fire regimes worldwide.
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Affiliation(s)
- Neal E Flanagan
- Nicholas School of the Environment, Duke University Wetland Center, Durham, NC, USA
| | - Hongjun Wang
- Nicholas School of the Environment, Duke University Wetland Center, Durham, NC, USA
| | - Scott Winton
- Nicholas School of the Environment, Duke University Wetland Center, Durham, NC, USA
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zurich, Switzerland
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Curtis J Richardson
- Nicholas School of the Environment, Duke University Wetland Center, Durham, NC, USA
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Sheremet A, Jones GM, Jarett J, Bowers RM, Bedard I, Culham C, Eloe-Fadrosh EA, Ivanova N, Malmstrom RR, Grasby SE, Woyke T, Dunfield PF. Ecological and genomic analyses of candidate phylum WPS-2 bacteria in an unvegetated soil. Environ Microbiol 2020; 22:3143-3157. [PMID: 32372527 DOI: 10.1111/1462-2920.15054] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 12/01/2022]
Abstract
Members of the bacterial candidate phylum WPS-2 (or Eremiobacterota) are abundant in several dry, bare soil environments. In a bare soil deposited by an extinct iron-sulfur spring, we found that WPS-2 comprised up to 24% of the bacterial community and up to 108 cells per g of soil based on 16S rRNA gene sequencing and quantification. A single genus-level cluster (Ca. Rubrimentiphilum) predominated in bare soils but was less abundant in adjacent forest. Nearly complete genomes of Ca. Rubrimentiphilum were recovered as single amplified genomes (SAGs) and metagenome-assembled genomes (MAGs). Surprisingly, given the abundance of WPS-2 in bare soils, the genomes did not indicate any capacity for autotrophy, phototrophy, or trace gas metabolism. Instead, they suggest a predominantly aerobic organoheterotrophic lifestyle, perhaps based on scavenging amino acids, nucleotides, and complex oligopeptides, along with lithotrophic capacity on thiosulfate. Network analyses of the entire community showed that some species of Chloroflexi, Actinobacteria, and candidate phylum AD3 (or Dormibacterota) co-occurred with Ca. Rubrimentiphilum and may represent ecological or metabolic partners. We propose that Ca. Rubrimentiphilum act as efficient heterotrophic scavengers. Combined with previous studies, these data suggest that the phylum WPS-2 includes bacteria with diverse metabolic capabilities.
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Affiliation(s)
- Andriy Sheremet
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Gareth M Jones
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Jessica Jarett
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Robert M Bowers
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Isaac Bedard
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | - Cassandra Culham
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
| | | | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Rex R Malmstrom
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | | | - Tanja Woyke
- Department of Energy Joint Genome Institute, Walnut Creek CA, 94598, USA
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW Calgary, Alberta, T2N 1N4, Canada
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Successional Variation in the Soil Microbial Community in Odaesan National Park, Korea. SUSTAINABILITY 2020. [DOI: 10.3390/su12114795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Succession is defined as variation in ecological communities caused by environmental changes. Environmental succession can be caused by rapid environmental changes, but in many cases, it is slowly caused by climate change or constant low-intensity disturbances. Odaesan National Park is a well-preserved forest located in the Taebaek mountain range in South Korea. The forest in this national park is progressing from a mixed-wood forest to a broad-leaved forest. In this study, microbial community composition was investigated using 454 sequencing of soil samples collected from 13 different locations in Odaesan National Park. We assessed whether microbial communities are affected by changes in environmental factors such as water content (WC), nutrient availability (total carbon (TC) and total nitrogen (TN)) and pH caused by forest succession. WC, TC, TN and pH significantly differed between the successional stages of the forest. The WC, TC and TN of the forest soils tended to increase as succession progressed, while pH tended to decrease. In both successional stages, the bacterial genus Pseudolabrys was the most abundant, followed by Afipia and Bradyrhizobium. In addition, the fungal genus Saitozyma showed the highest abundance in the forest soils. Microbial community composition changed according to forest successional stage and soil properties (WC, TC, TN, and pH). Furthermore, network analysis of both bacterial and fungal taxa revealed strong relationships of the microbial community depending on the soil properties affected by forest succession.
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Dove NC, Safford HD, Bohlman GN, Estes BL, Hart SC. High-severity wildfire leads to multi-decadal impacts on soil biogeochemistry in mixed-conifer forests. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02072. [PMID: 31925848 DOI: 10.1002/eap.2072] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 09/09/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
During the past century, systematic wildfire suppression has decreased fire frequency and increased fire severity in the western United States of America. While this has resulted in large ecological changes aboveground such as altered tree species composition and increased forest density, little is known about the long-term, belowground implications of altered, ecologically novel, fire regimes, especially on soil biological processes. To better understand the long-term implications of ecologically novel, high-severity fire, we used a 44-yr high-severity fire chronosequence in the Sierra Nevada where forests were historically adapted to frequent, low-severity fire, but were fire suppressed for at least 70 yr. High-severity fire in the Sierra Nevada resulted in a long-term (44 +yr) decrease (>50%, P < 0.05) in soil extracellular enzyme activities, basal microbial respiration (56-72%, P < 0.05), and organic carbon (>50%, P < 0.05) in the upper 5 cm compared to sites that had not been burned for at least 115 yr. However, nitrogen (N) processes were only affected in the most recent fire site (4 yr post-fire). Net nitrification increased by over 600% in the most recent fire site (P < 0.001), but returned to similar levels as the unburned control in the 13-yr site. Contrary to previous studies, we did not find a consistent effect of plant cover type on soil biogeochemical processes in mid-successional (10-50 yr) forest soils. Rather, the 44-yr reduction in soil organic carbon (C) quantity correlated positively with dampened C cycling processes. Our results show the drastic and long-term implication of ecologically novel, high-severity fire on soil biogeochemistry and underscore the need for long-term fire ecological experiments.
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Affiliation(s)
- Nicholas C Dove
- Environmental Systems Graduate Group, University of California, Merced, California, 95343, USA
| | - Hugh D Safford
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
- USDA-Forest Service, Pacific Southwest Region, Vallejo, California, 94592, USA
| | | | - Becky L Estes
- USDA-Forest Service, Pacific Southwest Research Station, Redding, California, 96002, USA
| | - Stephen C Hart
- Department of Life & Environmental Sciences and Sierra Nevada Research Institute, University of California, Merced, California, 95343, USA
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Ribeiro-Kumara C, Pumpanen J, Heinonsalo J, Metslaid M, Orumaa A, Jõgiste K, Berninger F, Köster K. Long-term effects of forest fires on soil greenhouse gas emissions and extracellular enzyme activities in a hemiboreal forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:135291. [PMID: 31843307 DOI: 10.1016/j.scitotenv.2019.135291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/23/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
Fire is the most important natural disturbance in boreal forests, and it has a major role regulating the carbon (C) budget of these systems. With the expected increase in fire frequency, the greenhouse gas (GHG) budget of boreal forest soils may change. In order to understand the long-term nature of the soil-atmosphere GHG exchange after fire, we established a fire chronosequence representing successional stages at 8, 19, 34, 65, 76 and 179 years following stand-replacing fires in hemiboreal Scots pine forests in Estonia. Changes in extracellular activity, litter decomposition, vegetation biomass, and soil physicochemical properties were assessed in relation to carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions. Soil temperature was highest 8 years after fire, whereas soil moisture varied through the fire chronosequences without a consistent pattern. Litter decomposition and CO2 efflux were still lower 8 years after fire compared with pre-fire levels (179 years after fire). Both returned to pre-fire levels before vegetation re-established, and CO2 efflux was only strongly responsive to temperature from 19 years after fire onward. Recovery of CO2 efflux in the long term was associated with a moderate effect of fire on enzyme activity, the input of above- and below-ground litter carbon, and the re-establishment of vegetation. Soil acted as a CH4 sink and N2O source similarly in all successional stages. Compared with soil moisture and time after fire, soil temperature was the most important predictor for both GHGs. The re-establishment of overstorey and vegetation cover (mosses and lichens) might have caused an increase in CH4 and N2O effluxes in the studied areas, respectively.
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Affiliation(s)
- Christine Ribeiro-Kumara
- University of Helsinki, Department of Forests Sciences, PO Box 27, Latokartanonkaari 7, 00014 Helsinki, Finland.
| | - Jukka Pumpanen
- University of Eastern Finland, Department of Environmental and Biological Sciences, PL 1627, 70211 Kuopio, Finland
| | - Jussi Heinonsalo
- University of Helsinki, Department of Forests Sciences, PO Box 27, Latokartanonkaari 7, 00014 Helsinki, Finland; Finnish Meteorological Institute, Climate System Research, Helsinki, Finland
| | - Marek Metslaid
- Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia; Norwegian Institute of Bioeconomy Research, PO Box 115, 1431 Ås, Norway
| | - Argo Orumaa
- Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia
| | - Kalev Jõgiste
- Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia
| | - Frank Berninger
- University of Eastern Finland, Department of Environmental and Biological Sciences, PL 111, 80101 Joensuu, Finland
| | - Kajar Köster
- University of Helsinki, Department of Forests Sciences, PO Box 27, Latokartanonkaari 7, 00014 Helsinki, Finland; Institute for Atmospheric and Earth System Research, Helsinki, Finland
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Ribeiro-Kumara C, Köster E, Aaltonen H, Köster K. How do forest fires affect soil greenhouse gas emissions in upland boreal forests? A review. ENVIRONMENTAL RESEARCH 2020; 184:109328. [PMID: 32163772 DOI: 10.1016/j.envres.2020.109328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
Wildfires strongly regulate carbon (C) cycling and storage in boreal forests and account for almost 10% of global fire C emissions. However, the anticipated effects of climate change on fire regimes may destabilize current C-climate feedbacks and switch the systems to new stability domains. Since most of these forests are located in upland soils where permafrost is widespread, the expected climate warming and drying combined with more active fires may alter the greenhouse gas (GHG) budgets of boreal forests and trigger unprecedented changes in the global C balance. Therefore, a better understanding of the effects of fires on the various spatial and temporal patterns of GHG fluxes of different physical environments (permafrost and nonpermafrost soils) is fundamental to an understanding of the role played by fire in future climate feedbacks. While large amounts of C are released during fires, postfire GHG fluxes play an important role in boreal C budgets over the short and long term. The timescale over which the vegetation cover regenerates seems to drive the recovery of C emissions after both low- and high-severity fires, regardless of fire-induced changes in soil decomposition. In soils underlain by permafrost, fires increase the active layer depth for several years, which may alter the soil dynamics regulating soil GHG exchange. In a scenario of global warming, prolonged exposition of previously immobilized C could result in higher carbon dioxide emission during the early fire succession. However, without knowledge of the contribution of each respiration component combined with assessment of the warming and drying effects on both labile and recalcitrant soil organic matter throughout the soil profile, we cannot advance on the most relevant feedbacks involving fire and permafrost. Fires seem to have either negligible effects on methane (CH4) fluxes or a slight increase in CH4 uptake. However, permafrost thawing driven by climate or fire could turn upland boreal soils into temporary CH4 sources, depending on how fast the transition from moist to drier soils occurs. Most studies indicate a slight decrease or no significant change in postfire nitrous oxide (N2O) fluxes. However, simulations have shown that the temperature sensitivity of denitrification exceeds that of soil respiration; thus, the effects of warming on soil N2O emissions may be greater than on C emissions.
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Affiliation(s)
- Christine Ribeiro-Kumara
- University of Helsinki, Department of Forest Sciences, PO Box 27, Latokartanonkaari 7, 00014, Helsinki, Finland.
| | - Egle Köster
- University of Helsinki, Department of Forest Sciences, PO Box 27, Latokartanonkaari 7, 00014, Helsinki, Finland
| | - Heidi Aaltonen
- University of Helsinki, Department of Forest Sciences, PO Box 27, Latokartanonkaari 7, 00014, Helsinki, Finland
| | - Kajar Köster
- University of Helsinki, Department of Forest Sciences, PO Box 27, Latokartanonkaari 7, 00014, Helsinki, Finland; Institute for Atmospheric and Earth System Research, University of Helsinki, Finland
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Zhang-Turpeinen H, Kivimäenpää M, Aaltonen H, Berninger F, Köster E, Köster K, Menyailo O, Prokushkin A, Pumpanen J. Wildfire effects on BVOC emissions from boreal forest floor on permafrost soil in Siberia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 711:134851. [PMID: 32000328 DOI: 10.1016/j.scitotenv.2019.134851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/28/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
One of the effects of climate change on boreal forest will be more frequent forest wildfires and permafrost thawing. These will increase the availability of soil organic matter (SOM) for microorganisms, change the ground vegetation composition and ultimately affect the emissions of biogenic volatile organic compounds (BVOCs), which impact atmospheric chemistry and climate. BVOC emissions from boreal forest floor have been little characterized in southern boreal region, and even less so in permafrost soil, which underlies most of the northern boreal region. Here, we report the long-term effects of wildfire on forest floor BVOC emission rates along a wildfire chronosequence in a Larix gmelinii forest in central Siberia. We determined forest floor BVOC emissions from forests exposed to wildfire 1, 23 and > 100 years ago. We studied how forest wildfires and the subsequent succession of ground vegetation, as well as changes in the availability of SOM along with the deepened and recovered active layer, influence BVOC emission rates. The forest floor acted as source of a large number of BVOCs in all forest age classes. Monoterpenes were the most abundant BVOC group in all age classes. The total BVOC emission rates measured from the 23- and >100-year-old areas were ca. 2.6 times higher than the emissions from the 1-year-old area. Lower emissions were related to a decrease in plant coverage and microbial decomposition of SOM after wildfire. Our results showed that forest wildfires play an important indirect role in regulating the amount and composition of BVOC emissions from post-fire originated boreal forest floor. This could have a substantial effect on BVOC emissions if the frequency of forest wildfires increases in the future as a result of climate warming.
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Affiliation(s)
- Huizhong Zhang-Turpeinen
- Department of Environmental and Biological Sciences, P.O.Box 1627, FI-70211 Kuopio, University of Eastern Finland, Finland.
| | - Minna Kivimäenpää
- Department of Environmental and Biological Sciences, P.O.Box 1627, FI-70211 Kuopio, University of Eastern Finland, Finland
| | - Heidi Aaltonen
- Department of Forest Sciences, P.O. Box 27, FI-00014 Helsinki, University of Helsinki, Finland
| | - Frank Berninger
- Department of Environmental and Biological Sciences, P.O.Box 111, FI-80101 Joensuu, University of Eastern Finland, Finland
| | - Egle Köster
- Department of Forest Sciences, P.O. Box 27, FI-00014 Helsinki, University of Helsinki, Finland; Institute for Atmospheric and Earth System Research/ Forest sciences, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Kajar Köster
- Department of Forest Sciences, P.O. Box 27, FI-00014 Helsinki, University of Helsinki, Finland; Institute for Atmospheric and Earth System Research/ Forest sciences, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | | | | | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, P.O.Box 1627, FI-70211 Kuopio, University of Eastern Finland, Finland
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Song W, Tong X, Liu Y, Li W. Microbial Community, Newly Sequestered Soil Organic Carbon, and δ 15N Variations Driven by Tree Roots. Front Microbiol 2020; 11:314. [PMID: 32174905 PMCID: PMC7056912 DOI: 10.3389/fmicb.2020.00314] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 02/12/2020] [Indexed: 12/04/2022] Open
Abstract
Rhizosphere microbes in forests are key elements of the carbon sequestration of terrestrial ecosystems. To date, little is known about how the diversity and species interactions of the active rhizomicrobial community change during soil carbon sequestration and what interactions drive these changes. In this study, we used a combination of DNA and stable isotope method to explore correlations between the composition of microbial communities, N transformation, and the sequestration de novo of carbon in soils around Pinus tabuliformis and Quercus variabilis roots in North China. Rhizosphere soils from degraded lands, primary stage land (tree roots had colonized in degraded soil for 1 year), and nature forest were sampled for analyses. The results showed that microbial communities and newly sequestered soil organic carbon (SOC) contents changed with different tree species, environments, and successive stages. The fungal unweighted and weighted UniFrac distances could better show the different microbial species structures and differences in successive stages. Newly sequestered SOC was positively correlated with the bacterial order Rhizobiales (in P. tabuliformis forests), the fungal order Russulales (in Q. variabilis forests), and δ15N. Consequently, the bacterial order Rhizobiales acted as an important taxa for P. tabuliformis root-driven carbon sequestration, and the fungal order Russulales acted as an important taxa for Q. variabilis root-driven carbon sequestration. The two plant species allocated root exudates to different portion of their root systems, which in turn altered microbial community composition and function. The δ15N of soil organic matter could be an important indicator to estimate root-driven carbon sequestration.
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Affiliation(s)
- Wenchen Song
- College of Forestry, Beijing Forestry University, Beijing, China
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaojuan Tong
- College of Forestry, Beijing Forestry University, Beijing, China
| | - Yanhong Liu
- Key Laboratory for Forest Resources and Ecosystem Processes of Beijing, Beijing Forestry University, Beijing, China
| | - Weike Li
- College of Forestry, Beijing Forestry University, Beijing, China
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Yang S, Zheng Q, Yang Y, Yuan M, Ma X, Chiariello NR, Docherty KM, Field CB, Gutknecht JLM, Hungate BA, Niboyet A, Le Roux X, Zhou J. Fire affects the taxonomic and functional composition of soil microbial communities, with cascading effects on grassland ecosystem functioning. GLOBAL CHANGE BIOLOGY 2020; 26:431-442. [PMID: 31562826 DOI: 10.1111/gcb.14852] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/18/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Fire is a crucial event regulating the structure and functioning of many ecosystems. Yet few studies have focused on how fire affects taxonomic and functional diversities of soil microbial communities, along with changes in plant communities and soil carbon (C) and nitrogen (N) dynamics. Here, we analyze these effects in a grassland ecosystem 9 months after an experimental fire at the Jasper Ridge Global Change Experiment site in California, USA. Fire altered soil microbial communities considerably, with community assembly process analysis showing that environmental selection pressure was higher in burned sites. However, a small subset of highly connected taxa was able to withstand the disturbance. In addition, fire decreased the relative abundances of most functional genes associated with C degradation and N cycling, implicating a slowdown of microbial processes linked to soil C and N dynamics. In contrast, fire stimulated above- and belowground plant growth, likely enhancing plant-microbe competition for soil inorganic N, which was reduced by a factor of about 2. To synthesize those findings, we performed structural equation modeling, which showed that plants but not microbial communities were responsible for significantly higher soil respiration rates in burned sites. Together, our results demonstrate that fire 'reboots' the grassland ecosystem by differentially regulating plant and soil microbial communities, leading to significant changes in soil C and N dynamics.
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Affiliation(s)
- Sihang Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Qiaoshu Zheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Mengting Yuan
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Xingyu Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Nona R Chiariello
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
| | - Kathryn M Docherty
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, USA
| | - Christopher B Field
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
| | - Jessica L M Gutknecht
- Department of Soil Ecology, Helmholtz Centre for Environmental Research - UFZ, Halle, Germany
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Audrey Niboyet
- Institut d'Ecologie et des Sciences de l'Environnement de Paris (Sorbonne Université, CNRS, INRA, IRD, Université Paris Diderot, UPEC), Paris, France
- AgroParisTech, Paris, France
| | - Xavier Le Roux
- Laboratoire d'Ecologie Microbienne, CNRS, INRA, Université de Lyon, Université Lyon 1, UMR INRA 1418, UMR CNRS 5557, Villeurbanne, France
| | - Jizhong Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Abstract
While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.IMPORTANCE Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions.
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Aalismail NA, Ngugi DK, Díaz-Rúa R, Alam I, Cusack M, Duarte CM. Functional metagenomic analysis of dust-associated microbiomes above the Red Sea. Sci Rep 2019; 9:13741. [PMID: 31551441 PMCID: PMC6760216 DOI: 10.1038/s41598-019-50194-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/06/2019] [Indexed: 02/08/2023] Open
Abstract
Atmospheric transport is a major vector for the long-range transport of microbial communities, maintaining connectivity among them and delivering functionally important microbes, such as pathogens. Though the taxonomic diversity of aeolian microorganisms is well characterized, the genomic functional traits underpinning their survival during atmospheric transport are poorly characterized. Here we use functional metagenomics of dust samples collected on the Global Dust Belt to initiate a Gene Catalogue of Aeolian Microbiome (GCAM) and explore microbial genetic traits enabling a successful aeolian lifestyle in Aeolian microbial communities. The GCAM reported here, derived from ten aeolian microbial metagenomes, includes a total of 2,370,956 non-redundant coding DNA sequences, corresponding to a yield of ~31 × 106 predicted genes per Tera base-pair of DNA sequenced for the aeolian samples sequenced. Two-thirds of the cataloged genes were assigned to bacteria, followed by eukaryotes (5.4%), archaea (1.1%), and viruses (0.69%). Genes encoding proteins involved in repairing UV-induced DNA damage and aerosolization of cells were ubiquitous across samples, and appear as fundamental requirements for the aeolian lifestyle, while genes coding for other important functions supporting the aeolian lifestyle (chemotaxis, aerotaxis, germination, thermal resistance, sporulation, and biofilm formation) varied among the communities sampled.
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Affiliation(s)
- Nojood A Aalismail
- Red Sea Research Centre (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955, Saudi Arabia.
| | - David K Ngugi
- Department of Microorganisms, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Culture, Inhoffenstrasse 7B, B38124, Braunschweig, Germany
| | - Rubén Díaz-Rúa
- Red Sea Research Centre (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955, Saudi Arabia
| | - Intikhab Alam
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Michael Cusack
- Red Sea Research Centre (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955, Saudi Arabia
| | - Carlos M Duarte
- Red Sea Research Centre (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955, Saudi Arabia
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Altshuler I, Hamel J, Turney S, Magnuson E, Lévesque R, Greer CW, Whyte LG. Species interactions and distinct microbial communities in high Arctic permafrost affected cryosols are associated with the CH 4 and CO 2 gas fluxes. Environ Microbiol 2019; 21:3711-3727. [PMID: 31206918 DOI: 10.1111/1462-2920.14715] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 05/27/2019] [Accepted: 06/10/2019] [Indexed: 11/29/2022]
Abstract
Microbial metabolism of the thawing organic carbon stores in permafrost results in a positive feedback loop of greenhouse gas emissions. CO2 and CH4 fluxes and the associated microbial communities in Arctic cryosols are important in predicting future warming potential of the Arctic. We demonstrate that topography had an impact on CH4 and CO2 flux at a high Arctic ice-wedge polygon terrain site, with higher CO2 emissions and lower CH4 uptake at troughs compared to polygon interior soils. The pmoA sequencing suggested that USCα cluster of uncultured methanotrophs is likely responsible for observed methane sink. Community profiling revealed distinct assemblages across the terrain at different depths. Deeper soils contained higher abundances of Verrucomicrobia and Gemmatimonadetes, whereas the polygon interior had higher Acidobacteria and lower Betaproteobacteria and Deltaproteobacteria abundances. Genome sequencing of isolates from the terrain revealed presence of carbon cycling genes including ones involved in serine and ribulose monophosphate pathways. A novel hybrid network analysis identified key members that had positive and negative impacts on other species. Operational Taxonomic Units (OTUs) with numerous positive interactions corresponded to Proteobacteria, Candidatus Rokubacteria and Actinobacteria phyla, while Verrucomicrobia and Acidobacteria members had negative impacts on other species. Results indicate that topography and microbial interactions impact community composition.
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Affiliation(s)
- Ianina Altshuler
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Jérémie Hamel
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, QC, Québec, Canada
| | - Shaun Turney
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Elisse Magnuson
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Roger Lévesque
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, QC, Québec, Canada
| | - Charles W Greer
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada.,National Research Council of Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Lyle G Whyte
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
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Aaltonen H, Palviainen M, Zhou X, Köster E, Berninger F, Pumpanen J, Köster K. Temperature sensitivity of soil organic matter decomposition after forest fire in Canadian permafrost region. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 241:637-644. [PMID: 30962006 DOI: 10.1016/j.jenvman.2019.02.130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 05/22/2023]
Abstract
Climate warming in arctic/subarctic ecosystems will result in increased frequency of forest fires, elevated soil temperatures and thawing of permafrost, which have implications for soil organic matter (SOM) decomposition rates, the CO2 emissions and globally significant soil C stocks in this region. It is still unclear how decomposability and temperature sensitivity of SOM varies in different depths and different stages of succession following forest fire in permafrost regions and studies on long term effects of forest fires in these areas are lacking. To study this question, we took soil samples from 5, 10 and 30 cm depths from forest stands in Northwest Canada, underlain by permafrost, that were burnt by wildfire 3, 25 and over 100 years ago. We measured heterotrophic soil respiration at 1, 7, 13 and 19 °C. Fire had a significant effect on the active layer depth, and it increased the temperature sensitivity (Q10) of respiration in the surface (5 cm) and in the deepest soil layer (30 cm) in the 3-year-old area compared to the 25- and more than 100-year-old areas. Also the metabolic quotient (qCO2) of soil microbes was increased after fire. Though fires may facilitate the SOM decomposition by increasing active layer depth, they also decreased SOM quality, which may limit the rate of decomposition. After fire all of these changes reverted back to original levels with forest succession.
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Affiliation(s)
- Heidi Aaltonen
- Department of Forest Sciences, University of Helsinki, PO Box 27 (Latokartanonkaari 7), Fi-00014, Finland.
| | - Marjo Palviainen
- Department of Forest Sciences, University of Helsinki, PO Box 27 (Latokartanonkaari 7), Fi-00014, Finland
| | - Xuan Zhou
- Department of Forest Sciences, University of Helsinki, PO Box 27 (Latokartanonkaari 7), Fi-00014, Finland
| | - Egle Köster
- Department of Forest Sciences, University of Helsinki, PO Box 27 (Latokartanonkaari 7), Fi-00014, Finland
| | - Frank Berninger
- Department of Environmental and Biological Sciences, University of Eastern Finland, PL 111, FI-80101 Joensuu, Finland
| | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PL 1627, FI-70211, Kuopio, Finland
| | - Kajar Köster
- Department of Forest Sciences, University of Helsinki, PO Box 27 (Latokartanonkaari 7), Fi-00014, Finland
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Tripathi BM, Kim HM, Jung JY, Nam S, Ju HT, Kim M, Lee YK. Distinct Taxonomic and Functional Profiles of the Microbiome Associated With Different Soil Horizons of a Moist Tussock Tundra in Alaska. Front Microbiol 2019; 10:1442. [PMID: 31316487 PMCID: PMC6610311 DOI: 10.3389/fmicb.2019.01442] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/07/2019] [Indexed: 11/13/2022] Open
Abstract
Permafrost-underlain tundra soils in Northern Hemisphere are one of the largest reservoirs of terrestrial carbon, which are highly sensitive to microbial decomposition due to climate warming. However, knowledge about the taxonomy and functions of microbiome residing in different horizons of permafrost-underlain tundra soils is still limited. Here we compared the taxonomic and functional composition of microbiome between different horizons of soil cores from a moist tussock tundra ecosystem in Council, Alaska, using 16S rRNA gene and shotgun metagenomic sequencing. The composition, diversity, and functions of microbiome varied significantly between soil horizons, with top soil horizon harboring more diverse communities than sub-soil horizons. The vertical gradient in soil physico-chemical parameters were strongly associated with composition of microbial communities across permafrost soil horizons; however, a large fraction of the variation in microbial communities remained unexplained. The genes associated with carbon mineralization were more abundant in top soil horizon, while genes involved in acetogenesis, fermentation, methane metabolism (methanogenesis and methanotrophy), and N cycling were dominant in sub-soil horizons. The results of phylogenetic null modeling analysis showed that stochastic processes strongly influenced the composition of the microbiome in different soil horizons, except the bacterial community composition in top soil horizon, which was largely governed by homogeneous selection. Our study expands the knowledge on the structure and functional potential of microbiome associated with different horizons of permafrost soil, which could be useful in understanding the effects of environmental change on microbial responses in tundra ecosystems.
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Affiliation(s)
| | - Hye Min Kim
- Environmental Safety Research Institute, NeoEnBiz, Bucheon, South Korea
| | - Ji Young Jung
- Korea Polar Research Institute, Incheon, South Korea
| | - Sungjin Nam
- Korea Polar Research Institute, Incheon, South Korea
| | - Hyeon Tae Ju
- Korea Polar Research Institute, Incheon, South Korea
| | - Mincheol Kim
- Korea Polar Research Institute, Incheon, South Korea
| | - Yoo Kyung Lee
- Korea Polar Research Institute, Incheon, South Korea
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Abstract
Climate change is causing shifts in precipitation patterns in the central grasslands of the United States, with largely unknown consequences on the collective physiological responses of the soil microbial community, i.e., the metaphenome. Here, we used an untargeted omics approach to determine the soil microbial community's metaphenomic response to soil moisture and to define specific metabolic signatures of the response. Specifically, we aimed to develop the technical approaches and metabolic mapping framework necessary for future systematic ecological studies. We collected soil from three locations at the Konza Long-Term Ecological Research (LTER) field station in Kansas, and the soils were incubated for 15 days under dry or wet conditions and compared to field-moist controls. The microbiome response to wetting or drying was determined by 16S rRNA amplicon sequencing, metatranscriptomics, and metabolomics, and the resulting shifts in taxa, gene expression, and metabolites were assessed. Soil drying resulted in significant shifts in both the composition and function of the soil microbiome. In contrast, there were few changes following wetting. The combined metabolic and metatranscriptomic data were used to generate reaction networks to determine the metaphenomic response to soil moisture transitions. Site location was a strong determinant of the response of the soil microbiome to moisture perturbations. However, some specific metabolic pathways changed consistently across sites, including an increase in pathways and metabolites for production of sugars and other osmolytes as a response to drying. Using this approach, we demonstrate that despite the high complexity of the soil habitat, it is possible to generate insight into the effect of environmental change on the soil microbiome and its physiology and functions, thus laying the groundwork for future, targeted studies.IMPORTANCE Climate change is predicted to result in increased drought extent and intensity in the highly productive, former tallgrass prairie region of the continental United States. These soils store large reserves of carbon. The decrease in soil moisture due to drought has largely unknown consequences on soil carbon cycling and other key biogeochemical cycles carried out by soil microbiomes. In this study, we found that soil drying had a significant impact on the structure and function of soil microbial communities, including shifts in expression of specific metabolic pathways, such as those leading toward production of osmoprotectant compounds. This study demonstrates the application of an untargeted multi-omics approach to decipher details of the soil microbial community's metaphenotypic response to environmental perturbations and should be applicable to studies of other complex microbial systems as well.
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Altshuler I, Ronholm J, Layton A, Onstott TC, W. Greer C, Whyte LG. Denitrifiers, nitrogen-fixing bacteria and N2O soil gas flux in high Arctic ice-wedge polygon cryosols. FEMS Microbiol Ecol 2019; 95:5481522. [DOI: 10.1093/femsec/fiz049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 04/24/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ianina Altshuler
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21,111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Jennifer Ronholm
- Department of Food Science and Agricultural Chemistry, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21,111 Lakeshore Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
- Department of Animal Science, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21,111 Lakeshore Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Alice Layton
- Center for Environmental Biotechnology, University of Tennessee – Knoxville, 676 Dabney-Buehler Hall, 1416 Circle Drive, TN 37996-1605, USA
| | - Tullis C Onstott
- Geomicrobiology, Geosciences, Princeton University, Princeton, NJ 08544, USA
| | - Charles W. Greer
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21,111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
- National Research Council of Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada
| | - Lyle G Whyte
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, 21,111 Lakeshore Rd, Ste Anne-de-Bellevue, QC, H9X 3V9, Canada
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