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Lin D, Zhang E, Liu E, Sun W, Wang R, Meng X, Ni Z, Wang Y, You Y. Human impacts overwhelmed climate as the dominant factor controlling lacustrine organic matter accumulation in Erhai Lake 2000 years ago, Southwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174182. [PMID: 38925392 DOI: 10.1016/j.scitotenv.2024.174182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 06/04/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024]
Abstract
Climate and human activity are two important factors in regulating organic matter (OM) accumulation in the lake environment. However, when and how anthropogenic impacts have affected lacustrine OM accumulation in southwest China during the late Holocene have not yet been well defined. Here, a 16.3-kyr n-alkane record derived from Erhai Lake was used to trace OM sources and explore their connections to climate and human activity. The n-alkane distributions indicated that the dominant sediment sources shifted from terrestrial and aquatic plants to algae in the late Holocene. OM accumulation was closely related to catchment soil erosion, sediment transport, and deposition processes regulated by climate conditions before 5.0 cal. kyr B.P., following the patterns that stronger monsoon precipitation favoured more terrestrial and less aquatic OM input, and vice versa. From 5.0 to 2.0 cal. kyr B.P., the synchronous downwards trends in terrestrial OM input and precipitation intensity indicated that climate remained a major driving force for OM accumulation. However, sediment sources experienced large-magnitude and centennial-scale oscillations between allochthonous and autochthonous inputs, reflecting early human impacts appeared and lake ecosystems retained the self-regulated ability to recover from the basin-wide early moderate human disturbances. Afterwards, the increased (decreased) OM contributions from terrestrial (aquatic) plants contradicted the weakening monsoon precipitation since 2.0 cal. kyr B.P., indicating a dominant effect of human activities on OM accumulation. This change was accompanied by highly improved algae productivity and gradually elevated lacustrine trophic status, and the lake ecosystem eventually shifted into another state largely deviating from its climate-driven background due to intensified deforestation and agricultural cultivation. Regional comparison indicated that anthropogenic disturbances have temporal differences in southwest China. This study will further improve our understanding of past climate-human-environment interactions in southwest China.
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Affiliation(s)
- Durui Lin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enlou Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China.
| | - Enfeng Liu
- College of Geography and Environment, Shandong Normal University, Jinan 250358, China
| | - Weiwei Sun
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Rong Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xianqiang Meng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Zhenyu Ni
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yao Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yang You
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Liu Z, Wang J, Xie J, Yao D, Yang S, Ge J. Interactions among heavy metals and methane-metabolizing microorganisms and their effects on methane emissions in Dajiuhu peatland. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:37415-37426. [PMID: 36572772 DOI: 10.1007/s11356-022-24868-8] [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: 06/28/2022] [Accepted: 12/15/2022] [Indexed: 06/18/2023]
Abstract
Peatlands play a crucial role in mediating the emissions of methane through active biogeochemical cycling of accumulated carbon driven by methane-metabolizing microorganisms; meanwhile, they serve as vital archives of atmospheric heavy metal deposition. Despite many edaphic factors confirmed as determinants to modulate the structure of methanotrophic and methanogenic communities, recognition of interactions among them is limited. In this study, peat soils were collected from Dajiuhu peatland to assess the presence of heavy metals, and methanotrophs and methanogens were investigated via high-throughput sequencing for functional genes mcrA and pmoA. Further analyses of the correlations between methane-related functional groups were conducted. The results demonstrated that both methane-metabolizing microorganisms and heavy metals have prominent vertical heterogeneity upward and downward along the depth of 20 cm. Pb, Cd, and Hg strongly correlated with methanotrophs and methanogens across all seasons and depths, serving as forceful factors in structural variations of methanogenic and methanotrophic communities. Particularly, Pb, Cd, and Hg were identified as excessive elements in Dajiuhu peatland. Furthermore, seasonal variations of networks among methane-related functional groups and environmental factors significantly affected the changes of methane fluxes across different seasons. Concretely, the complicated interactions were detrimental to methane emissions in the Dajiuhu peatland, leading to the minimum methane emissions in winter. Our study identified the key heavy metals affecting the composition of methane-metabolizing microorganisms and linkages between seasonal variations of methane emissions and interaction among heavy metals and methane-metabolizing microorganisms, which provided much new reference and theoretical basis for integrated management of natural peatlands.
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Affiliation(s)
- Ziwei Liu
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China
| | - Jiumei Wang
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China
| | - Jinlin Xie
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China
| | - Dong Yao
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China
| | - Shiyu Yang
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China
| | - Jiwen Ge
- School of Environmental Studies, China University of Geosciences (Wuhan), 68 Jincheng Street, Hongshan District, Wuhan, 430078, Hubei Province, China.
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China.
- Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, China University of Geosciences (Wuhan), Wuhan, 430078, China.
- Institution of Ecology and Environmental Sciences, China University of Geosciences (Wuhan), Wuhan, 430078, China.
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Li J, Li M, Zhao L, Sun X, Gao M, Sheng L, Bian H. Characteristics of soil carbon emissions and bacterial community composition in peatlands at different stages of vegetation succession. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156242. [PMID: 35643137 DOI: 10.1016/j.scitotenv.2022.156242] [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: 04/06/2022] [Revised: 05/09/2022] [Accepted: 05/22/2022] [Indexed: 05/16/2023]
Abstract
Microorganisms are important components of soil ecosystems and play an important role in material cycles. Northern peatlands are important ecosystems in middle-high latitude regions. In peatlands, different vegetation successions occur with changes in groundwater levels. The overall carbon emission of peat bogs is related to the carbon stability of the surrounding environment. Unraveling the assembly and distribution of bacterial communities at different succession stages in peatland is essential to understanding the soil nutrient cycle. In this study, we investigated the characteristics of soil carbon emissions and the composition of subsurface microorganisms under six different succession stages. The highest carbon emission was observed in mossy peatlands, and their soil enzyme activity was closely related to the aboveground vegetation cover type. The succession pattern of ground vegetation was the main driver of soil microorganisms. The abundance of the dominant Proteobacteria decreased with increasing soil depth, while the opposite trend was observed for Chloroflexi. Furthermore, the community structure of microorganisms became progressively simpler and looser as soil water content decreased. The bacterial alpha diversity was driven by soil dissolved organic carbon and Fe, and the beta diversity was driven mainly by soil water content. The bacteria presented a random distribution in a nutrient-rich soil environment and shifted to deterministic distribution with decreasing water and nutrient contents. The balance between taxonomic diversity and dispersal limitation mediates species coexistence in the soil microbiome. This study provides new insights into the soil environment at different stages of succession in peatlands.
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Affiliation(s)
- Jianwei Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Ming Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Liyuan Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Xiaoqian Sun
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Minghao Gao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Lianxi Sheng
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Hongfeng Bian
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China.
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Hu T, Mao Y, Liu W, Shi M, Cheng C, Xu A, Su Y, Li X, Zhang Y, Zhang Z, Qi S, Xing X. Deposition records of polycyclic aromatic hydrocarbons and black carbon in peat core from Dajiuhu, Shennongjia, Central China: human activity imprint since the industrial revolution. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:56234-56246. [PMID: 34046838 DOI: 10.1007/s11356-021-14383-7] [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: 01/31/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are a kind of organic pollutants with carcinogenic, teratogenic, and mutagenic effects. This study aims to assess the effects of changes in China's socio-economic indicators represented by energy consumption and number of motor vehicles, on PAHs and black carbon (BC) deposition. For this, a 50-cm peat core from Dajiuhu peatland, Central China, was collected and divided into 50 subsamples to establish a sedimentary record of about 200 years with radioactive 210Pb. The Σ16PAH concentration ranged from 212.67 to 830.10 ng·g-1, mainly composed of 2- and 3-ring PAHs, and BC ranged from 7.89 to 36.48%. The deposition characteristics of BC first increased and then decreased from the core bottom to the top. The predominant of the carcinogenic PAHs (C-PAHs) was Dibenzo[a,h]anthracene (DBA) before 1949, and then changed to Benzo[b]fluoranthene (BbF). Ratio of Fla/Pyr, (3+4)-ring/(5+6)-ring PAHs, and BaA/(BaA+Chr), IcdP/(IcdP+BghiP) suggested that long-range atmospheric transmission (LRAT) and pyrogenic were the main PAHs sources, but that local PAH emission contribution gradually increased since 1990, and mixed (petroleum and combustion) sources were the dominant since 2000. The high concentration of Phenanthrene (Phe) and Naphthalene (Nap) were likely from plant product. Furthermore, increased concentrations of 4-, 5-, and 6-ring PAHs showed significant correlations with increased coal and petroleum consumption and the number of motor vehicles, respectively, and this influence has strengthened after 2000. These were caused by rapid urbanization and industrialization following the implementation of the reform and opening up policy in 1978, and a new round of urbanization after 2000.
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Affiliation(s)
- Tianpeng Hu
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Yao Mao
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Weijie Liu
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Mingming Shi
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Cheng Cheng
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - An Xu
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Yewang Su
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Xingyu Li
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Yunchao Zhang
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Zhiqi Zhang
- Shennongjia National Park Administration, Shennongjia, 442400, China
| | - Shihua Qi
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Xinli Xing
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China.
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Tian W, Xiang X, Wang H. Differential Impacts of Water Table and Temperature on Bacterial Communities in Pore Water From a Subalpine Peatland, Central China. Front Microbiol 2021; 12:649981. [PMID: 34122363 PMCID: PMC8193233 DOI: 10.3389/fmicb.2021.649981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/01/2021] [Indexed: 11/21/2022] Open
Abstract
The level of water table and temperature are two environmental variables shaping soil bacterial communities, particularly in peatland ecosystems. However, discerning the specific impact of these two factors on bacterial communities in natural ecosystems is challenging. To address this issue, we collected pore water samples across different months (August and November in 2017 and May 2018) with a gradient of water table changes and temperatures at the Dajiuhu peatland, Central China. The samples were analyzed with 16S rRNA high-throughput sequencing and Biolog EcoMicroplates. Bacterial communities varied in the relative abundances of dominant taxa and harbored exclusive indicator operational taxonomic units across the different months. Despite these differences, bacterial communities showed high similarities in carbon utilization, with preferences for esters (pyruvic acid methyl ester, Tween 40, Tween 80, and D-galactonic acid γ-lactone), amino acids (L-arginine and L-threonine), and amines (phenylethylamine and putrescine). However, rates of carbon utilization (as indicated by average well-color development) and metabolic diversity (McIntosh and Shannon index) in May and August were higher than those in November. Redundancy analysis revealed that the seasonal variations in bacterial communities were significantly impacted by the level of the water table, whereas the temperature had a fundamental role in bacterial carbon utilization rate. Co-occurrence analysis identified Sphingomonas, Mucilaginibacter, Novosphingobium, Lacunisphaera, Herminiimonas, and Bradyrhizobium as keystone species, which may involve in the utilization of organic compounds such as amino acids, phenols, and others. Our findings suggest that bacterial community functions were more stable than their compositions in the context of water table changes. These findings significantly expand our current understanding of the variations of bacterial community structures and metabolic functions in peatland ecosystems in the context of global warming and fluctuation of the water table.
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Affiliation(s)
- Wen Tian
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Xing Xiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- College of Life Science, Shangrao Normal University, Shangrao, China
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- School of Environmental Studies, China University of Geosciences, Wuhan, China
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Liu H, Gu Y, Qin Y, Yu Z, Huang X, Xie S, Zheng M, Zhang Z, Cheng S. The elemental enrichments at Dajiuhu Peatland in the Middle Yangtze Valley in response to changes in East Asian monsoon and human activity since 20,000 cal yr BP. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143990. [PMID: 33316522 DOI: 10.1016/j.scitotenv.2020.143990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/30/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
Here we present multiproxy inorganic geochemical records from a peat core (ZK5) from the Dajiuhu Basin in central China to investigate peatland deposition processes and atmospheric metal pollution and to explore their relationships with East Asian monsoon change and human activities in the Middle Yangtze Valley since 20,000 cal yr BP. The peat physicochemical data including total organic carbon (TOC), trace elements, and grain-size show that the site has changed from a lake during the cold-wet Last Glacial Maximum (LGM; 20,000-18,000 cal yr BP), to a marshy wetland during the mild last deglaciation (18,000-11,500 cal yr BP) and a peatland during the mostly warm and dry Holocene (11,500 cal yr BP-present). This general sequence corresponds with changes in East Asian monsoon indicated by stalagmites δ18O records and boreal summer insolation. Marked decreases in trace element concentrations correspond to two periods of peatland expansion during the abrupt hydroclimatic transitions from the LGM to the last deglaciation and from the last deglaciation to the early Holocene. Warm-dry mid-Holocene might induce high organic matter decomposition in peat sediments. Increasing natural element concentrations since the late Holocene are correlated with the weakening of the summer monsoon and elevated atmospheric dust deposition. Increasing Cu and Pb concentrations in peat record indicate large-scale Cu smelting during the Bronze Age and excessive coal burning during the 10th century or so. The anthropogenic heavy metals were transported by prevailing East Asian summer monsoon and deposited in the Dajiuhu Basin during periods of heightened human activities. Our compilation of heavy metals records across China confirmed the noticeable impacts of the historical human activity on deposition environments during the late Holocene. Consequently, trace elements from the Dajiuhu Basin are reliable proxies for capturing monsoon climate-induced peatland deposition response and present important evidence for a historical atmospheric heavy metal pollution in the Middle Yangtze Valley. Our results offer useful references for peatland evolution and protection under the background of global change.
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Affiliation(s)
- Hongye Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; Hubei Key Laboratory of Wetland Evolution & Eco-Restoration (WEER), China University of Geosciences, Wuhan 430074, China
| | - Yansheng Gu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; Hubei Key Laboratory of Wetland Evolution & Eco-Restoration (WEER), China University of Geosciences, Wuhan 430074, China.
| | - Yangmin Qin
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; Hubei Key Laboratory of Wetland Evolution & Eco-Restoration (WEER), China University of Geosciences, Wuhan 430074, China
| | - Zicheng Yu
- Department of Earth and Environmental Sciences, Lehigh University, Bethlehem, PA 18015, USA; Institute for Peat and Mire Research, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China
| | - Xianyu Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Shucheng Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Min Zheng
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Zhiqi Zhang
- Hubei Key Laboratory of Wetland Evolution & Eco-Restoration (WEER), China University of Geosciences, Wuhan 430074, China; Shennongjia National Park Administration, Shennongjia 442400, Hubei, China
| | - Shenggao Cheng
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
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Lin W, Zhang W, Paterson GA, Zhu Q, Zhao X, Knight R, Bazylinski DA, Roberts AP, Pan Y. Expanding magnetic organelle biogenesis in the domain Bacteria. MICROBIOME 2020; 8:152. [PMID: 33126926 PMCID: PMC7602337 DOI: 10.1186/s40168-020-00931-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. RESULTS Here, we perform the most comprehensive metagenomic analysis available of MTB communities and reconstruct metagenome-assembled MTB genomes from diverse ecosystems. Discovery of MTB in acidic peatland soils suggests widespread MTB occurrence in waterlogged soils in addition to subaqueous sediments and water bodies. A total of 168 MTB draft genomes have been reconstructed, which represent nearly a 3-fold increase over the number currently available and more than double the known MTB species at the genome level. Phylogenomic analysis reveals that these genomes belong to 13 Bacterial phyla, six of which were previously not known to include MTB. These findings indicate a much wider taxonomic distribution of magnetosome organelle biogenesis across the domain Bacteria than previously thought. Comparative genome analysis reveals a vast diversity of magnetosome gene clusters involved in magnetosomal biogenesis in terms of gene content and synteny residing in distinct taxonomic lineages. Phylogenetic analyses of core magnetosome proteins in this largest available and taxonomically diverse dataset support an unexpectedly early evolutionary origin of magnetosome biomineralization, likely ancestral to the origin of the domain Bacteria. CONCLUSIONS These findings expand the taxonomic and phylogenetic diversity of MTB across the domain Bacteria and shed new light on the origin and evolution of microbial magnetoreception. Potential biogenesis of the magnetosome organelle in the close descendants of the last bacterial common ancestor has important implications for our understanding of the evolutionary history of bacterial cellular complexity and emphasizes the biological significance of the magnetosome organelle. Video Abstract.
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Affiliation(s)
- Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China.
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China.
| | - Wensi Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Greig A Paterson
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, L69 7ZE, Liverpool, UK
| | - Qiyun Zhu
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92037, USA
| | - Xiang Zhao
- Research School of Earth Sciences, Australian National University, ACT, Canberra, 2601, Australia
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92037, USA
| | - Dennis A Bazylinski
- School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV, 89154-4004, USA
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, ACT, Canberra, 2601, Australia
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China.
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China.
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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8
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van Winden JF, Talbot HM, Reichart G, McNamara NP, Benthien A, Sinninghe Damsté JS. Influence of temperature on the δ 13 C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs. GEOBIOLOGY 2020; 18:497-507. [PMID: 32180328 PMCID: PMC7383571 DOI: 10.1111/gbi.12389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 02/08/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
Methane emissions from peat bogs are mitigated by methanotrophs, which live in symbiosis with peat moss (e.g. Sphagnum). Here, we investigate the influence of temperature and resultant changes in methane fluxes on Sphagnum and methanotroph-related biomarkers, evaluating their potential as proxies in ancient bogs. A pulse-chase experiment using 13 C-labelled methane in the field clearly showed label uptake in diploptene, a biomarker for methanotrophs, demonstrating in situ methanotrophic activity in Sphagnum under natural conditions. Peat cores containing live Sphagnum were incubated at 5, 10, 15, 20 and 25°C for two months, causing differences in net methane fluxes. The natural δ13 C values of diploptene extracted from Sphagnum showed a strong correlation with temperature and methane production. The δ13 C values ranged from -34‰ at 5°C to -41‰ at 25°C. These results are best explained by enhanced expression of the methanotrophic enzymatic isotope effect at higher methane concentrations. Hence, δ13 C values of diploptene, or its diagenetic products, potentially provide a useful tool to assess methanotrophic activity in past environments. Increased methane fluxes towards Sphagnum did not affect δ13 C values of bulk Sphagnum and its specific marker, the C23 n-alkane. The concentration of methanotroph-specific bacteriohopanepolyols (BHPs), aminobacteriohopanetetrol (aminotetrol, characteristic for type II and to a lesser extent type I methanotrophs) and aminobacteriohopanepentol (aminopentol, a marker for type I methanotrophs) showed a non-linear response to increased methane fluxes, with relatively high abundances at 25°C compared to those at 20°C or below. Aminotetrol was more abundant than aminopentol, in contrast to similar abundances of aminotetrol and aminopentol in fresh Sphagnum. This probably indicates that type II methanotrophs became prevalent under the experimental conditions relative to type I methanotrophs. Even though BHP concentrations may not directly reflect bacterial activity, they may provide insight into the presence of different types of methanotrophs.
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Affiliation(s)
- Julia F. van Winden
- Department of Earth SciencesFaculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| | - Helen M. Talbot
- School of Civil Engineering and GeoscienceNewcastle UniversityNewcastle upon TyneUK
- Present address:
Department of Archaeology (BioArCh)University of YorkYorkUK
| | - Gert‐Jan Reichart
- Department of Earth SciencesFaculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
- Departments of Marine Microbiology and Biogeochemistry and Ocean SystemsNIOZ Royal Netherlands Institute for Sea Research, and Utrecht UniversityDen BurgThe Netherlands
| | - Niall P. McNamara
- UK Centre for Ecology & HydrologyLancaster Environment CentreLancasterUK
| | - Albert Benthien
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Jaap S. Sinninghe Damsté
- Department of Earth SciencesFaculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
- Departments of Marine Microbiology and Biogeochemistry and Ocean SystemsNIOZ Royal Netherlands Institute for Sea Research, and Utrecht UniversityDen BurgThe Netherlands
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9
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Chen X, McGowan S, Bu ZJ, Yang XD, Cao YM, Bai X, Zeng LH, Liang J, Qiao QL. Diatom-based water-table reconstruction in Sphagnum peatlands of northeastern China. WATER RESEARCH 2020; 174:115648. [PMID: 32126414 DOI: 10.1016/j.watres.2020.115648] [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: 08/05/2019] [Revised: 02/18/2020] [Accepted: 02/22/2020] [Indexed: 06/10/2023]
Abstract
Peatlands are important ecosystems for biodiversity conservation, global carbon cycling and water storage. Hydrological changes due to climate variability have accelerated the degradation of global and regional ecosystem services of peatlands. Diatoms are important producers and bioindicators in wetlands, but comprehensive diatom-based inference models for palaeoenvironmental reconstruction in peatlands are scarce. To explore the use of diatoms for investigating peatland hydrological change, this study established a training set consisting of diatom composition and twelve environmental factors from 105 surface samples collected from five Sphagnum peatlands in northeastern China. Diatom communities were dominated by Eunotia species. Ordination analyses showed that depth to the water table (DWT) was the most important factor influencing diatom distribution, independently accounting for 4.99% of total variance in diatom data. Accordingly, a diatom-based DWT transfer function was developed and thoroughly tested. The results revealed that the best-performing model was based on weighted averaging with inverse deshrinking (R2 = 0.66, RMSEP = 8.8 cm with leave-one-out cross validation). Quantitative reconstruction of DWT on a short peat core collected from the Aershan Peatland (Inner Mongolia) recorded climate-mediated hydrological changes over the last two centuries. This study presents the first diatom-water table transfer function in Sphagnum peatlands, and highlights the potential of diatoms as a powerful tool to assess the magnitude of past hydrological changes in peatlands of northeastern China, as well as similar peaty environments worldwide.
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Affiliation(s)
- Xu Chen
- Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430074, China.
| | - Suzanne McGowan
- School of Geography, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Zhao-Jun Bu
- Institute for Peat and Mire Research, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China.
| | - Xiang-Dong Yang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yan-Min Cao
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, China
| | - Xue Bai
- Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Ling-Han Zeng
- School of Geography, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Jia Liang
- Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Qiang-Long Qiao
- Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430074, China
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10
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Tian W, Xiang X, Ma L, Evers S, Wang R, Qiu X, Wang H. Rare Species Shift the Structure of Bacterial Communities Across Sphagnum Compartments in a Subalpine Peatland. Front Microbiol 2020; 10:3138. [PMID: 32038572 PMCID: PMC6986206 DOI: 10.3389/fmicb.2019.03138] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 12/27/2019] [Indexed: 12/17/2022] Open
Abstract
Sphagnum-associated microbiomes are crucial to Sphagnum growth and peatland ecological functions. However, roles of rare species in bacterial communities across Sphagnum compartments are poorly understood. Here the structures of rare taxa (RT) and conditionally abundant and rare taxa (CART) from Sphagnum palustre peat (SP), S. palustre ectosphere (Ecto) and S. palustre endosphere (Endo) were investigated in the Dajiuhu Peatland, central China. Our results showed that plant compartment effects significantly altered the diversities and structures of bacterial communities. The Observed species and Simpson indices of RT and CART in alpha diversity significantly increased from Endo to SP, with those of Ecto in-between. The variations of community dissimilarities of RT and CART among compartments were consistent with those of whole bacterial communities (WBC). Network analysis indicated a non-random co-occurrence pattern of WBC and all keystone species are affiliated with RT and CART, indicating their important role in sustaining the WBC. Furthermore, the community structures of RT and CART in SP were significantly shaped by water table and total nitrogen content, which coincided with the correlations between WBC and environmental factors. Collectively, our results for the first time confirm the importance of rare species to bacterial communities through structural and predicted functional analyses, which expands our understanding of rare species in Sphagnum-associated microbial communities in subalpine peatlands.
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Affiliation(s)
- Wen Tian
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Xing Xiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Liyuan Ma
- School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Stephanie Evers
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, United Kingdom
- TROCARI (Tropical Catchment Research Initiative), Semenyih, Malaysia
| | - Ruicheng Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Xuan Qiu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- School of Environmental Studies, China University of Geosciences, Wuhan, China
- Laboratory of Basin Hydrology and Wetland Eco-Restoration, China University of Geosciences, Wuhan, China
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