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Walter Anthony KM, Anthony P, Hasson N, Edgar C, Sivan O, Eliani-Russak E, Bergman O, Minsley BJ, James SR, Pastick NJ, Kholodov A, Zimov S, Euskirchen E, Bret-Harte MS, Grosse G, Langer M, Nitzbon J. Upland Yedoma taliks are an unpredicted source of atmospheric methane. Nat Commun 2024; 15:6056. [PMID: 39025864 PMCID: PMC11258132 DOI: 10.1038/s41467-024-50346-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 07/02/2024] [Indexed: 07/20/2024] Open
Abstract
Landscape drying associated with permafrost thaw is expected to enhance microbial methane oxidation in arctic soils. Here we show that ice-rich, Yedoma permafrost deposits, comprising a disproportionately large fraction of pan-arctic soil carbon, present an alternate trajectory. Field and laboratory observations indicate that talik (perennially thawed soils in permafrost) development in unsaturated Yedoma uplands leads to unexpectedly large methane emissions (35-78 mg m-2 d-1 summer, 150-180 mg m-2 d-1 winter). Upland Yedoma talik emissions were nearly three times higher annually than northern-wetland emissions on an areal basis. Approximately 70% emissions occurred in winter, when surface-soil freezing abated methanotrophy, enhancing methane escape from the talik. Remote sensing and numerical modeling indicate the potential for widespread upland talik formation across the pan-arctic Yedoma domain during the 21st and 22nd centuries. Contrary to current climate model predictions, these findings imply a positive and much larger permafrost-methane-climate feedback for upland Yedoma.
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Affiliation(s)
- K M Walter Anthony
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, USA.
| | - P Anthony
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, USA
| | - N Hasson
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, USA
| | - C Edgar
- Institute of Arctic Biology, University Alaska Fairbanks, Fairbanks, AK, USA
| | - O Sivan
- Department of Earth and Environmental Sciences, Ben Gurion University of the Negev, Beersheva, Israel
| | - E Eliani-Russak
- Department of Earth and Environmental Sciences, Ben Gurion University of the Negev, Beersheva, Israel
| | - O Bergman
- Water and Environmental Research Center, University Alaska Fairbanks, Fairbanks, AK, USA
- Department of Earth and Environmental Sciences, Ben Gurion University of the Negev, Beersheva, Israel
| | - B J Minsley
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, CO, USA
| | - S R James
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, CO, USA
| | - N J Pastick
- U.S. Geological Survey, Earth Resources Observation and Science Center, Sioux Falls, SD, USA
| | - A Kholodov
- Geophysical Research Institute, University Alaska Fairbanks, Fairbanks, AK, USA
| | - S Zimov
- Pacific Geographical Institute of the Russian Academy of Sciences, Northeast Science Station, Cherskiy, Russia
| | - E Euskirchen
- Institute of Arctic Biology, University Alaska Fairbanks, Fairbanks, AK, USA
| | - M S Bret-Harte
- Institute of Arctic Biology, University Alaska Fairbanks, Fairbanks, AK, USA
| | - G Grosse
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
- University of Potsdam, Institute of Geosciences, Potsdam, Germany
| | - M Langer
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
- Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - J Nitzbon
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
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Wang T, Deng Z, Zhang C, Zou Y, Xie Y, Li F, Xiao F, Peng C. Vegetation types and flood water level are dominant factors controlling the carbon sequestration potential in Dongting Lake floodplain, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171146. [PMID: 38401724 DOI: 10.1016/j.scitotenv.2024.171146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
Wetlands are important carbon sinks. However, the carbon sequestration potential of flooded wetlands may be weakened owing to water regime changes induced by anthropogenic disturbances. Using the eddy covariance technique, this study quantified the effects of the water level and vegetation types on the net ecosystem CO2 exchange (NEE), gross primary production (GPP), and ecosystem respiration (Reco) from a reed marsh (Miscanthus sacchariflorus) and a sedge meadow (Carex spp.) in the Dongting Lake floodplain from 2014 to 2016. Our results indicated that the sedge meadow (-89.49 to -186.47 g C m-2 y-1) and reed marsh (-246.12 to -513.94 g C m-2 y-1) were carbon sinks on the interannual timescale. However, the sedge meadow changed from a carbon sink to a carbon source during the flooding season. The effect of flooding on the carbon sink function in the reed marsh was dependent on the water level. The carbon sink function of the reed marsh was enhanced by moderate flooding (water level under 30.5 m in Chenglingji) owing to the inhibition of Reco, but was weakened by extremely high-water levels (over 33 m in Chenglingji) during the flooding season. Seasonal variations in NEE, GPP, and Reco were closely related to photosynthetic photon flux density, soil water content, water level, soil temperature, and air temperature. We can conclude that the increase in reed area combined with the decrease in flooding days in the sedge meadow can potentially enhance the carbon sink function of the Dongting Lake floodplain.
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Affiliation(s)
- Tao Wang
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Zhengmiao Deng
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Hunan Key Laboratory of Remote Sensing Monitoring of Ecological Environment in Dongting Lake Area, Hunan Natural Resources Affairs Center, Changsha 410004, China; Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
| | - Chengyi Zhang
- National Climate Center, China Meteorological Administration, Beijing 100081, China
| | - Yeai Zou
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China
| | - Yonghong Xie
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
| | - Feng Li
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China
| | - Fengjin Xiao
- National Climate Center, China Meteorological Administration, Beijing 100081, China
| | - Changhui Peng
- School of Geographic Sciences, Hunan Normal University, Changsha 410081, China; Department of Biology Sciences, University of Quebec at Montreal, C.P. 8888, Succ. Centre-Ville, Montreal H3C 3P8, Canada
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Structuring Life After Death: Plant Leachates Promote CO2 Uptake by Regulating Microbial Biofilm Interactions in a Northern Peatland Ecosystem. Ecosystems 2023. [DOI: 10.1007/s10021-023-00820-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
AbstractShifts in plant functional groups associated with climate change have the potential to influence peatland carbon storage by altering the amount and composition of organic matter available to aquatic microbial biofilms. The goal of this study was to evaluate the potential for plant subsidies to regulate ecosystem carbon flux (CO2) by governing the relative proportion of primary producers (microalgae) and heterotrophic decomposers (heterotrophic bacteria) during aquatic biofilm development in an Alaskan fen. We evaluated biofilm composition and CO2 flux inside mesocosms with and without nutrients (both nitrogen and phosphorus), organic carbon (glucose), and leachates from common peatland plants (moss, sedge, shrub, horsetail). Experimental mesocosms were exposed to either natural sunlight or placed under a dark canopy to evaluate the response of decomposers to nutrients and carbon subsidies with and without algae, respectively. Algae were limited by inorganic nutrients and heterotrophic bacteria were limited by organic carbon. The quality of organic matter varied widely among plants and leachate nutrient content, more so than carbon quality, influenced biofilm composition. By alleviating nutrient limitation of algae, plant leachates shifted the biofilm community toward autotrophy in the light-transparent treatments, resulting in a significant reduction in CO2 emissions compared to the control. Without the counterbalance from algal photosynthesis, a heterotrophic biofilm significantly enhanced CO2 emissions in the presence of plant leachates in the dark. These results show that plants not only promote carbon uptake directly through photosynthesis, but also indirectly through a surrogate, the phototrophic microbes.
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Kwon MJ, Ballantyne A, Ciais P, Qiu C, Salmon E, Raoult N, Guenet B, Göckede M, Euskirchen ES, Nykänen H, Schuur EAG, Turetsky MR, Dieleman CM, Kane ES, Zona D. Lowering water table reduces carbon sink strength and carbon stocks in northern peatlands. GLOBAL CHANGE BIOLOGY 2022; 28:6752-6770. [PMID: 36039832 PMCID: PMC9805217 DOI: 10.1111/gcb.16394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Peatlands at high latitudes have accumulated >400 Pg carbon (C) because saturated soil and cold temperatures suppress C decomposition. This substantial amount of C in Arctic and Boreal peatlands is potentially subject to increased decomposition if the water table (WT) decreases due to climate change, including permafrost thaw-related drying. Here, we optimize a version of the Organizing Carbon and Hydrology In Dynamic Ecosystems model (ORCHIDEE-PCH4) using site-specific observations to investigate changes in CO2 and CH4 fluxes as well as C stock responses to an experimentally manipulated decrease of WT at six northern peatlands. The unmanipulated control peatlands, with the WT <20 cm on average (seasonal max up to 45 cm) below the surface, currently act as C sinks in most years (58 ± 34 g C m-2 year-1 ; including 6 ± 7 g C-CH4 m-2 year-1 emission). We found, however, that lowering the WT by 10 cm reduced the CO2 sink by 13 ± 15 g C m-2 year-1 and decreased CH4 emission by 4 ± 4 g CH4 m-2 year-1 , thus accumulating less C over 100 years (0.2 ± 0.2 kg C m-2 ). Yet, the reduced emission of CH4 , which has a larger greenhouse warming potential, resulted in a net decrease in greenhouse gas balance by 310 ± 360 g CO2-eq m-2 year-1 . Peatlands with the initial WT close to the soil surface were more vulnerable to C loss: Non-permafrost peatlands lost >2 kg C m-2 over 100 years when WT is lowered by 50 cm, while permafrost peatlands temporally switched from C sinks to sources. These results highlight that reductions in C storage capacity in response to drying of northern peatlands are offset in part by reduced CH4 emissions, thus slightly reducing the positive carbon climate feedbacks of peatlands under a warmer and drier future climate scenario.
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Affiliation(s)
- Min Jung Kwon
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
- Institute of Soil ScienceUniversity of HamburgHamburgGermany
| | - Ashley Ballantyne
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
- Department of Ecosystem and Conservation ScienceUniversity of MontanaMissoulaMontanaUSA
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
| | - Chunjing Qiu
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
- INRAE, AgroParisTech, Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Elodie Salmon
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
| | - Nina Raoult
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
| | - Bertrand Guenet
- Laboratoire des Sciences du Climat et de l'EnvironnementCEA‐CNRS‐UVSQGif‐sur‐YvetteFrance
- Laboratoire de Géologie, Ecole Normale SupérieureCNRS, PSL Research UniversityParisFrance
| | - Mathias Göckede
- Systems DepartmentMax Planck Institute for BiogeochemistryJenaGermany
| | | | - Hannu Nykänen
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandKuopioFinland
| | - Edward A. G. Schuur
- College of the Environment, Forestry, and Natural SciencesNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Merritt R. Turetsky
- Institute of Arctic and Alpine ResearchUniversity of ColoradoBoulderColoradoUSA
| | | | - Evan S. Kane
- College of Forest Resources and Environmental ScienceMichigan Technological UniversityHoughtonMichiganUSA
- USDA Forest Service Northern Research StationHoughtonMichiganUSA
| | - Donatella Zona
- Department of Animal and Plant ScienceUniversity of SheffieldSheffieldUK
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
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Rober AR, McCann KS, Turetsky MR, Wyatt KH. Cascading effects of predators on algal size structure. JOURNAL OF PHYCOLOGY 2022; 58:308-317. [PMID: 35032342 DOI: 10.1111/jpy.13235] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
The presence of edible and inedible prey species in a food web can influence the strength that nutrients (bottom-up) or herbivores (top-down) have on primary production. In boreal peatlands, wetter more nutrient-rich conditions associated with ongoing climate change are expanding consumer access to aquatic habitat and promoting sources of primary production (i.e., algae) that are susceptible to trophic regulation. Here, we used an in situ mesocosm experiment to evaluate the consequences of enhanced nutrient availability and food-web manipulation (herbivore and predator exclusion) on algal assemblage structure in an Alaskan fen. Owing to the potential for herbivores to selectively consume edible algae (small cells) in favor of more resistant forms, we predicted that the proportion of less-edible algae (large cells) would determine the strength of top-down or bottom-up effects. Consistent with these expectations, we observed an increase in algal-cell size in the presence of herbivores (2-tiered food web) that was absent in the presence of a trophic cascade (3-tiered food web), suggesting that predators indirectly prevented morphological changes in the algal assemblage by limiting herbivory. Increases in algal-cell size with herbivory were driven by a greater proportion of filamentous green algae and nitrogen-fixing cyanobacteria, whose size and morphological characteristics mechanically minimize consumption. While consumer-driven shifts in algal assemblage structure were significant, they did not prevent top-down regulation of biofilm development by herbivores. Our findings show that increasing wet periods in northern peatlands will provide new avenues for trophic regulation of algal production, including directly through consumption and indirectly via a trophic cascade.
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Affiliation(s)
- Allison R Rober
- Department of Biology, Ball State University, Muncie, Indiana, 47306, USA
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, NIG 2WI, Canada
| | - Merritt R Turetsky
- Institute of Arctic and Alpine Research and Ecology and Evolutionary Biology Department, University of Colorado Boulder, Boulder, Colorado, 80309, USA
| | - Kevin H Wyatt
- Department of Biology, Ball State University, Muncie, Indiana, 47306, USA
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The Rhizosphere Responds: Rich Fen Peat and Root Microbial Ecology after Long-Term Water Table Manipulation. Appl Environ Microbiol 2021; 87:e0024121. [PMID: 33811029 DOI: 10.1128/aem.00241-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hydrologic shifts due to climate change will affect the cycling of carbon (C) stored in boreal peatlands. Carbon cycling in these systems is carried out by microorganisms and plants in close association. This study investigated the effects of experimentally manipulated water tables (lowered and raised) and plant functional groups on the peat and root microbiomes in a boreal rich fen. All samples were sequenced and processed for bacterial, archaeal (16S DNA genes; V4), and fungal (internal transcribed spacer 2 [ITS2]) DNA. Depth had a strong effect on microbial and fungal communities across all water table treatments. Bacterial and archaeal communities were most sensitive to the water table treatments, particularly at the 10- to 20-cm depth; this area coincides with the rhizosphere or rooting zone. Iron cyclers, particularly members of the family Geobacteraceae, were enriched around the roots of sedges, horsetails, and grasses. The fungal community was affected largely by plant functional group, especially cinquefoils. Fungal endophytes (particularly Acephala spp.) were enriched in sedge and grass roots, which may have underappreciated implications for organic matter breakdown and cycling. Fungal lignocellulose degraders were enriched in the lowered water table treatment. Our results were indicative of two main methanogen communities, a rooting zone community dominated by the archaeal family Methanobacteriaceae and a deep peat community dominated by the family Methanomicrobiaceae. IMPORTANCE This study demonstrated that roots and the rooting zone in boreal fens support organisms likely capable of methanogenesis, iron cycling, and fungal endophytic association and are directly or indirectly affecting carbon cycling in these ecosystems. These taxa, which react to changes in the water table and associate with roots and, particularly, graminoids, may gain greater biogeochemical influence, as projected higher precipitation rates could lead to an increased abundance of sedges and grasses in boreal fens.
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Wyatt KH, McCann KS, Rober AR, Turetsky MR. Letter: Trophic interactions regulate peatland carbon cycling. Ecol Lett 2021; 24:781-790. [PMID: 33554469 DOI: 10.1111/ele.13697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/28/2020] [Accepted: 01/06/2021] [Indexed: 12/01/2022]
Abstract
Peatlands are the most efficient natural ecosystems for long-term storage of atmospheric carbon. Our understanding of peatland carbon cycling is based entirely on bottom-up controls regulated by low nutrient availability. Recent studies have shown that top-down controls through predator-prey dynamics can influence ecosystem function, yet this has not been evaluated in peatlands to date. Here, we used a combination of nutrient enrichment and trophic-level manipulation to test the hypothesis that interactions between nutrient availability (bottom-up) and predation (top-down) influence peatland carbon fluxes. Elevated nutrients stimulated bacterial biomass and organic matter decomposition. In the absence of top-down regulation, carbon dioxide (CO2 ) respiration driven by greater decomposition was offset by elevated algal productivity. Herbivores accelerated CO2 emissions by removing algal biomass, while predators indirectly reduced CO2 emissions by muting herbivory in a trophic cascade. This study demonstrates that trophic interactions can mitigate CO2 emissions associated with elevated nutrient levels in northern peatlands.
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Affiliation(s)
- Kevin H Wyatt
- Department of Biology, Ball State University, Muncie, IN, 47306, USA
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, Guelph, ON, NIG2WI, Canada
| | - Allison R Rober
- Department of Biology, Ball State University, Muncie, IN, 47306, USA
| | - Merritt R Turetsky
- Institute of Arctic and Alpine Research and Ecology and Evolutionary Biology Department, University of Colorado Boulder, Boulder, CO, 80309, USA
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