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Li Q, Song Z, Xia S, Kuzyakov Y, Yu C, Fang Y, Chen J, Wang Y, Shi Y, Luo Y, Li Y, Chen J, Wang W, Zhang J, Fu X, Vancov T, Van Zwieten L, Liu CQ, Wang H. Microbial Necromass, Lignin, and Glycoproteins for Determining and Optimizing Blue Carbon Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:468-479. [PMID: 38141044 DOI: 10.1021/acs.est.3c08229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Coastal wetlands contribute to the mitigation of climate change through the sequestration of "blue carbon". Microbial necromass, lignin, and glycoproteins (i.e., glomalin-related soil proteins (GRSP)), as important components of soil organic carbon (SOC), are sensitive to environmental change. However, their contributions to blue carbon formation and the underlying factors remain largely unresolved. To address this paucity of knowledge, we investigated their contributions to blue carbon formation along a salinity gradient in coastal marshes. Our results revealed decreasing contributions of microbial necromass and lignin to blue carbon as the salinity increased, while GRSP showed an opposite trend. Using random forest models, we showed that their contributions to SOC were dependent on microbial biomass and resource stoichiometry. In N-limited saline soils, contributions of microbial necromass to SOC decreased due to increased N-acquisition enzyme activity. Decreases in lignin contributions were linked to reduced mineral protection offered by short-range-ordered Fe (FeSRO). Partial least-squares path modeling (PLS-PM) further indicated that GRSP could increase microbial necromass and lignin formation by enhancing mineral protection. Our findings have implications for improving the accumulation of refractory and mineral-bound organic matter in coastal wetlands, considering the current scenario of heightened nutrient discharge and sea-level rise.
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Affiliation(s)
- Qiang Li
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300192, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Zhaoliang Song
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300192, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Shaopan Xia
- Institute of Resource, Ecosystem and Environment of Agriculture, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Goettingen, Göttingen 37077, Germany
- Institute of Environmental Sciences, Kazan Federal University, Kazan 420049, Russia
- Peoples Friendship University of Russia (RUDN University), Moscow 117198, Russia
| | - Changxun Yu
- Department of Biology and Environmental Science, Linnaeus University, Kalmar 39231, Sweden
| | - Yunying Fang
- Australian Rivers Institute, School of Environment and Science, Griffith University, Nathan 4111, Australia
| | - Ji Chen
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Department of Agroecology, Aarhus University, Tjele 8830, Denmark
| | - Yidong Wang
- Tianjin Key Laboratory of Water Resources and Environment, & School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Yu Shi
- School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Yu Luo
- Institute of Soil & Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yongchun Li
- School of Environmental and Resource Sciences, Zhejiang A&F University, Zhejiang, Hangzhou 311300, China
| | - Junhui Chen
- School of Environmental and Resource Sciences, Zhejiang A&F University, Zhejiang, Hangzhou 311300, China
| | - Wei Wang
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
| | - Jianchao Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300192, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Xiaoli Fu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300192, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Tony Vancov
- NSW Department of Planning, Industry & Environment, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia
| | - Lukas Van Zwieten
- Wollongbar Primary Industries Institute, NSW Department of Primary Industries, Wollongbar, NSW 2477, Australia
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300192, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Hailong Wang
- Institute of Soil & Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
- School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, China
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Zhang X, Zhang C, Liu Y, Zhang R, Li M. Non-negligible roles of archaea in coastal carbon biogeochemical cycling. Trends Microbiol 2022; 31:586-600. [PMID: 36567186 DOI: 10.1016/j.tim.2022.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 12/25/2022]
Abstract
Coastal zones are among the world's most productive ecosystems. They store vast amounts of organic carbon, as 'blue carbon' reservoirs, and impact global climate change. Archaeal communities are integral components of coastal microbiomes but their ecological roles are often overlooked. However, archaeal diversity, metabolism, evolution, and interactions, revealed by recent studies using rapidly developing cutting-edge technologies, place archaea as important players in coastal carbon biogeochemical cycling. We here summarize the latest advances in the understanding of archaeal carbon cycling processes in coastal ecosystems, specifically, archaeal involvement in CO2 fixation, organic biopolymer transformation, and methane metabolism. We also showcase the potential to use of archaeal communities to increase carbon sequestration and reduce methane production, with implications for mitigating climate change.
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Affiliation(s)
- Xinxu Zhang
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Cuijing Zhang
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Yang Liu
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Rui Zhang
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China.
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Seasonal and Zonal Succession of Bacterial Communities in North Sea Salt Marsh Sediments. Microorganisms 2022; 10:microorganisms10050859. [PMID: 35630305 PMCID: PMC9146408 DOI: 10.3390/microorganisms10050859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 02/01/2023] Open
Abstract
Benthic microbial communities of intertidal zones perform important biogeochemical processes and provide accessible nutrients for higher organisms. To unravel the ecosystem services of salt marsh microbial communities, we analyzed bacterial diversity and metabolic potential along the land–sea transition zone on seasonal scales on the German North Sea Island of Spiekeroog. Analysis of bacterial community was based on amplicon sequencing of 16S rRNA genes and –transcripts. Insights into potential community function were obtained by applying the gene prediction tool tax4fun2. We found that spatial variation of community composition was greater than seasonal variations. Alphaproteobacteria (15%), Gammaproteobacteria (17%) and Planctomycetes (11%) were the most abundant phyla across all samples. Differences between the DNA-based resident and RNA-based active communities were most pronounced within the Planctomycetes (17% and 5%) and Cyanobacteriia (3% and 12%). Seasonal differences were seen in higher abundance of Gammaproteobacteria in March 2015 (25%) and a cyanobacterial summer bloom, accounting for up to 70% of the active community. Taxonomy-based prediction of function showed increasing potentials for nitrification, assimilatory nitrate and sulfate reduction from sea to land, while the denitrification and dissimilatory sulfate reduction increased towards the sea. In conclusion, seasonal differences mainly occurred by blooming of individual taxa, while the overall community composition strongly corresponded to locations. Shifts in their metabolism could drive the salt marsh’s function, e.g., as a potential nitrogen sink.
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Furtak K, Grządziel J, Gałązka A. Can Model Experiments Give Insight into the Response of the Soil Environment to Flooding? A Comparison of Microcosm and Natural Event. BIOLOGY 2022; 11:biology11030386. [PMID: 35336760 PMCID: PMC8945539 DOI: 10.3390/biology11030386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/21/2022] [Accepted: 02/26/2022] [Indexed: 11/16/2022]
Abstract
Studies using soil microcosms are very common, but few involve flooded soils, and comparing the results from such an experiment with natural conditions is unheard of. In the present study, we investigated the biological activity of soil (pH value, dehydrogenases and phosphatase activities) and the metabolic potential (EcoPlate™ Biolog®) of soil microorganisms in three fluvisol subjected to flooding under laboratory and natural conditions. The results indicate that soil flooding under both natural and laboratory conditions affected soil pH, enzymatic activity and metabolic potential (AWCD, average well colour development) of soil microorganisms. Changes in these parameters are more pronounced in the microcosmic experiment than in the field conditions. Furthermore, depending on the characteristics of the soil (i.e., its type, structure, vegetation) some of the soil quality parameters may return to their preflood state. Microcosm studies are needed in environmental ecology and microbiology to predict changes due to various factors, but their scale and course must be carefully planned.
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Gao GF, Peng D, Wu D, Zhang Y, Chu H. Increasing Inundation Frequencies Enhance the Stochastic Process and Network Complexity of the Soil Archaeal Community in Coastal Wetlands. Appl Environ Microbiol 2021; 87:e02560-20. [PMID: 33741614 PMCID: PMC8208137 DOI: 10.1128/aem.02560-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 03/07/2021] [Indexed: 01/03/2023] Open
Abstract
Coastal wetlands are experiencing frequent flooding because of global climate changes, such as the rising sea level. Despite the key role of archaea in soil biogeochemical cycles, the assembly processes and co-occurrence patterns of archaeal communities in coastal wetlands in response to increasing inundation frequencies remain elusive. In this study, we established an in situ mesocosm with an inundation frequency gradient to investigate the response of soil archaeal community toward increasing inundation frequencies in monocultures of Spartina alterniflora and a mangrove species, Kandelia obovata Both neutral community model and null model analyses suggested that stochastic processes are dominant in governing the archaeal community assembly and that the stochastic processes are enhanced with increasing inundation frequencies. Increasing inundation frequencies significantly increased the community niche width. Moreover, archaeal community in S. alterniflora soil displayed lower niche overlap and higher stochasticity than in K. obovata soil. Co-occurrence network analysis revealed that the network complexity increases with increase in the inundation frequencies. Soil water content is the most decisive factor influencing the archaeal communities. Overall, we found that increasing inundation frequencies enhance the stochastic processes and network complexity of the soil archaeal community in coastal wetlands. This study could enhance our understanding on the response of soil archaeal communities in coastal wetlands toward global change.IMPORTANCE Coastal wetlands, subjected to regular disturbances by periodic tides, are highly productive and important in the regulation of climate change. However, the assembly mechanisms and co-occurrence patterns of soil archaeal communities in coastal areas remain poorly known, especially for their responses to increasing inundation frequencies. In this study, we aimed at unraveling these uncertainties by studying typical estuarine ecosystems in southern China. We show that increasing inundation frequencies enhance the stochastic processes and network complexity of the soil archaeal community. This study offers a new path for an improved understanding of archaeal community assembly and species coexistence in coastal environments, with a special focus on the role of inundation frequency.
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Affiliation(s)
- Gui-Feng Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Dan Peng
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Di Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yihui Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Haiyan Chu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
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Shen R, Lan Z, Rinklebe J, Nie M, Hu Q, Yan Z, Fang C, Jin B, Chen J. Flooding variations affect soil bacterial communities at the spatial and inter-annual scales. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 759:143471. [PMID: 33213905 DOI: 10.1016/j.scitotenv.2020.143471] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Hydrological variations have substantial effects on the diversity and composition of soil bacterial communities in wetlands. At the spatial scale, the responses of soil bacterial diversity and composition to hydrological variations in wetlands have been extensively investigated. However, at the temporal scale, especially at the inter-annual scale, the corresponding bacterial responses are rarely reported. Therefore, we explored the effects of flooding variations on the diversity and composition of soil bacterial communities at a lakeshore wetland in two hydrological contrasting years. Three flooding variables, i.e. flooding duration (FD), total duration of the growing season (TGD), and exposure duration of the growing season (EGD), were used to characterize flooding regime. Soil bacterial communities were determined using 16S rRNA gene sequencing method. We found a very high soil bacterial diversity at the lakeshore wetland. The Shannon's indexes of soil bacterial communities varied from 5.61 to 7.11 in two years. Soil bacterial α-diversity followed a unimodal curve along the elevation gradient, and was significantly lower in the flooding year than in the drought year. Principal coordinate analysis demonstrated that the compositions of soil bacterial communities were separated in order of elevation and year along the first and second axes, respectively. The apparent habitat preferences of soil bacterial families were closely connected with their respiratory traits, and this trend was stronger at the inter-annual scale than at the spatial scale. Soil bacterial compositions were predominantly determined by the direct (by changing respiratory traits) and indirect (by changing soil pH) effects of TGD at the spatial scale, while they were simultaneously regulated by the direct effects of three flooding variables at the inter-annual scale. Our results enhance the understanding of soil microbial communities in wetlands and have large implications for developing general theories to predicting soil microbial functions.
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Affiliation(s)
- Ruichang Shen
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecosystem, Institute of Life Science and School of Life Science, Nanchang University, Nanchang 330031, China; Institute of Biodiversity Science, Fudan University, Shanghai 200433, China; Jiangxi Poyang Lake Wetland Conservation and Restoration National Permanent Scientific Research Base, National Ecosystem Research Station of Jiangxi Poyang Lake Wetland, Nanchang 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330031, China; Jiangxi Institute of Ecological Civilization, Nanchang University, Nanchang 330031, China.
| | - Zhichun Lan
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecosystem, Institute of Life Science and School of Life Science, Nanchang University, Nanchang 330031, China; Institute of Biodiversity Science, Fudan University, Shanghai 200433, China; Jiangxi Poyang Lake Wetland Conservation and Restoration National Permanent Scientific Research Base, National Ecosystem Research Station of Jiangxi Poyang Lake Wetland, Nanchang 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330031, China; Jiangxi Institute of Ecological Civilization, Nanchang University, Nanchang 330031, China
| | - Jörg Rinklebe
- School of Architecture and Civil Engineering, Laboratory of Soil- and Groundwater-Management, University of Wuppertal, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy, and Geoinformatics, Sejong University, Seoul 05006, Republic of Korea
| | - Ming Nie
- Institute of Biodiversity Science, Fudan University, Shanghai 200433, China
| | - Qiwu Hu
- School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
| | - Zhifeng Yan
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Changming Fang
- Institute of Biodiversity Science, Fudan University, Shanghai 200433, China
| | - Bingsong Jin
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecosystem, Institute of Life Science and School of Life Science, Nanchang University, Nanchang 330031, China; Jiangxi Poyang Lake Wetland Conservation and Restoration National Permanent Scientific Research Base, National Ecosystem Research Station of Jiangxi Poyang Lake Wetland, Nanchang 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330031, China; Jiangxi Institute of Ecological Civilization, Nanchang University, Nanchang 330031, China
| | - Jiakuan Chen
- Institute of Biodiversity Science, Fudan University, Shanghai 200433, China
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Gao GF, Peng D, Zhang Y, Li Y, Fan K, Tripathi BM, Adams JM, Chu H. Dramatic change of bacterial assembly process and co-occurrence pattern in Spartina alterniflora salt marsh along an inundation frequency gradient. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142546. [PMID: 33035970 DOI: 10.1016/j.scitotenv.2020.142546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/02/2020] [Accepted: 09/19/2020] [Indexed: 05/20/2023]
Abstract
Exotic Spartina alterniflora has become widely distributed along most of the coastlines in China in a wide range of inundation frequencies. However, the assembly processes and co-occurrence patterns of the bacterial community in S. alterniflora wetlands under different inundation frequencies remain elusive. In this study, an in-situ mesocosm was established to investigate the changes in soil bacterial community. We found that soil water content was the most decisive factor in influencing the bacterial community. Balanced variation, rather than abundance gradients, accounted for the major shifts in bacterial communities and was significantly and positively correlated with the changes in water content, suggesting that species substitution was facilitated by the increased water content. Deterministic processes were dominant in community assembly, and a large degree of change in water content increased variable selection. Co-occurrence network revealed that increasing water content significantly decreased the average degree and the relative abundance of keystone species, resulting in a network with less complexity. Structural equation modelling suggests that increasing inundation frequency has strong impacts on bacterial community, primarily by altering water content, network degree, and the relative abundance of keystone species. Overall, our results illustrate that increasing inundation frequency significantly influences the bacterial community assembly processes and co-occurrence patterns.
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Affiliation(s)
- Gui-Feng Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China
| | - Dan Peng
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Yihui Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Yuntao Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kunkun Fan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Binu M Tripathi
- Korea Polar Research Institute, Incheon 21990, Republic of Korea
| | - Jonathan M Adams
- School of Geography and Ocean Science, Nanjing University, 163 Xianlin Road, Nanjing 210023, China
| | - Haiyan Chu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Liu S, Trevathan-Tackett SM, Ewers Lewis CJ, Huang X, Macreadie PI. Macroalgal Blooms Trigger the Breakdown of Seagrass Blue Carbon. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14750-14760. [PMID: 33103882 DOI: 10.1021/acs.est.0c03720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Intensive macroalgal blooms, a source of labile organic carbon (LOC) induced by coastal nutrient loading in some seagrass ecosystems, create ideal conditions for enhanced recalcitrant organic carbon (ROC) loss via the cometabolism effect. Here, we carried out a 62-day laboratory experiment to see if density-dependent addition of macroalgal biomass can influence the seagrass decomposition process, including seagrass detritus carbon chemistry, greenhouse emissions, and bacterial communities. We found that higher density macroalgal addition stimulated microbes to decompose ∼20% more of the seagrass biomass compared to other treatments, which was also reflected in enhanced (∼twofold) greenhouse gas emissions. Although the composition of the seagrass-associated microbiome communities was unaffected by the addition of macroalgae, we showed that high macroalgal addition caused a relative depletion in the ROC as lignin and lipid compounds, as well as δ13C depletion and δ15N enrichment of the seagrass detritus. These results suggest that macroalgal blooms may stimulate the remineralization of recalcitrant components of seagrass detritus via cometabolism, possibly through providing available energy or resources for the synthesis of ROC-degrading enzymes within the resident microbial population. This study provides evidence that cometabolism can be a mechanism for leading to reduced seagrass blue carbon sequestration and preservation.
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Affiliation(s)
- Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria 3125, Australia
| | - Stacey M Trevathan-Tackett
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria 3125, Australia
| | - Carolyn J Ewers Lewis
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria 3125, Australia
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22911, United States
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Peter I Macreadie
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria 3125, Australia
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Liu S, Deng Y, Jiang Z, Wu Y, Huang X, Macreadie PI. Nutrient loading diminishes the dissolved organic carbon drawdown capacity of seagrass ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 740:140185. [PMID: 32563887 DOI: 10.1016/j.scitotenv.2020.140185] [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: 03/11/2020] [Revised: 05/18/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Seawater dissolved organic carbon (DOC) in seagrass meadows is gaining attention for its role in carbon sequestration. Abundant refractory compounds in DOC are exported by seagrass meadows to the deep sea, thereby contributing to long-term carbon drawdown. DOC lability and bacterioplankton communities are key determining factors in this carbon sequestration process, and it has been hypothesized that these may be affected by nutrient loading - however, scientific evidence is so far weak. Here, we studied the response of DOC composition and bacterioplankton communities to nutrient loading in seagrass meadows of the South China Sea. We found that increasing nutrient loads enhanced nitrogen and phosphorus concentrations in DOC, which promoted algae blooms (i.e. epiphyte, phytoplankton and macroalgae) in seagrass meadows, and presumably increased the lability of DOC and its bioavailability to microbes. Also, the relative abundance of K-strategist bacterioplankton communities with the potential to degrade refractory compounds (Acidimicrobiia, Verrucomicrobiales and Micrococcales) increased in the seagrass meadows exposed to high nutrient loads. These results suggest that high nutrient loading can enhance labile DOC composition, and thus increase refractory DOC remineralization rate, thereby weakening the DOC contribution potential of seagrass meadows to long-term carbon sequestration.
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Affiliation(s)
- Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yiqin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Peter I Macreadie
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
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