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Kang M, Liu L, Grossart HP. Spatio-temporal variations of methane fluxes in sediments of a deep stratified temperate lake. iScience 2024; 27:109520. [PMID: 38591008 PMCID: PMC11000008 DOI: 10.1016/j.isci.2024.109520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/09/2023] [Accepted: 03/14/2024] [Indexed: 04/10/2024] Open
Abstract
Spatio-temporal variability of sediment-mediated methane (CH4) production in freshwater lakes causes large uncertainties in predicting global lake CH4 emissions under different climate change and eutrophication scenarios. We conducted extensive sediment incubation experiments to investigate CH4 fluxes in Lake Stechlin, a deep, stratified temperate lake. Our results show contrasting spatial patterns in CH4 fluxes between littoral and profundal sites. The littoral sediments, ∼33% of the total sediment surface area, contributed ∼86.9% of the annual CH4 flux at the sediment-water interface. Together with sediment organic carbon quality, seasonal stratification is responsible for the striking spatial difference in sediment CH4 production between littoral and profundal zones owing to more sensitive CH4 production than oxidation to warming. While profundal sediments produce a relatively small amount of CH4, its production increases markedly as anoxia spreads in late summer. Our measurements indicate that future lake CH4 emissions will increase due to climate warming and concomitant hypoxia/anoxia.
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Affiliation(s)
- Manchun Kang
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Yichang 443002, China
- Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir, Yichang 443002, China
| | - Liu Liu
- Yunnan Key Laboratory of Plateau Geographical Processes and Environmental Changes, Faculty of Geography, Yunnan Normal University, Kunming 650500, China
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, 16775 Stechlin, Germany
| | - Hans-Peter Grossart
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, 16775 Stechlin, Germany
- Institute of Biochemistry and Biology, Potsdam University, 14476 Potsdam, Germany
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2
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Goranov AI, Chen H, Duan J, Myneni SCB, Hatcher PG. Potentially Massive and Global Non-Pyrogenic Production of Condensed "Black" Carbon through Biomass Oxidation. Environ Sci Technol 2024; 58:2750-2761. [PMID: 38294931 PMCID: PMC10867845 DOI: 10.1021/acs.est.3c05448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 02/02/2024]
Abstract
With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a charcoal-like ConAC-rich material. ConAC was also produced during laboratory oxidations of pine, maple, and brown-rotted oak woods, as well as algae, corn root, and tree bark. Back-of-the-envelope calculations suggest that biomass oxidation could be producing massive non-pyrogenic ConAC fluxes to terrestrial and aquatic environments. These estimates (e.g., 163-182 Tg-ConAC/year to soils) are much higher than the estimated pyrogenic "BC" fluxes (e.g., 128 Tg-ConAC/year to soils) implying that environmental ConAC is primarily non-pyrogenic. This novel perspective suggests that wildfire research trajectories should shift to assessing non-pyrogenic ConAC sources and fluxes, developing new methods for quantifying true BC, and establishing a new view of ConAC as an intermediate species in the biogeochemical processing of biomass during soil humification, aquatic photochemistry, microbial degradation, or mineral-organic matter interactions. We also advise against using BC or pyrogenic carbon (pyC) terminologies for ConAC measured in environmental matrices, unless a pyrogenic source can be confidently assigned.
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Affiliation(s)
- Aleksandar I. Goranov
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529 United States
| | - Hongmei Chen
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529 United States
| | - Jianshu Duan
- Department
of Geosciences, Princeton University, Princeton, New Jersey 08544 United States
| | - Satish C. B. Myneni
- Department
of Geosciences, Princeton University, Princeton, New Jersey 08544 United States
| | - Patrick G. Hatcher
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529 United States
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3
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Barba J, Brewer PE, Pangala SR, Machacova K. Methane emissions from tree stems - current knowledge and challenges: an introduction to a Virtual Issue. New Phytol 2024; 241:1377-1380. [PMID: 38267825 DOI: 10.1111/nph.19512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
This article is a Commentary on the Virtual Issue ‘Methane emissions from tree stems – current knowledge and challenges’ that includes the following papers: Barba et al. (2019), Bréchet et al. (2021), Covey & Megonigal (2019), Feng et al. (2022), Flanagan et al. (2021), Jeffrey et al. (2019, 2021, 2023), Kohl et al. (2019), Machacova et al. (2021a,b, 2023), Megonigal et al. (2020), Pangala et al. (2013, 2014), Pitz & Megonigal (2017), Plain et al. (2019), Putkinen et al. (2021), Sjögersten et al. (2020), Takahashi et al. (2022), Tenhovirta et al. (2022), Wang et al. (2016), and Yip et al. (2018). Access the Virtual Issue at www.newphytologist.com/virtualissues.
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Affiliation(s)
- Josep Barba
- CREAF, E-08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat de Girona, E-17003, Girona, Catalonia, Spain
| | - Paul E Brewer
- School of Life Sciences, Arizona State University, Tempe, AZ, 84287, USA
| | - Sunitha R Pangala
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Katerina Machacova
- Global Change Research Institute of the Czech Academy of Sciences, CZ-60300, Brno, Czech Republic
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4
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Ren Y, Wang H, Harrison SP, Prentice IC, Atkin OK, Smith NG, Mengoli G, Stefanski A, Reich PB. Reduced global plant respiration due to the acclimation of leaf dark respiration coupled with photosynthesis. New Phytol 2024; 241:578-591. [PMID: 37897087 DOI: 10.1111/nph.19355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023]
Abstract
Leaf dark respiration (Rd ) acclimates to environmental changes. However, the magnitude, controls and time scales of acclimation remain unclear and are inconsistently treated in ecosystem models. We hypothesized that Rd and Rubisco carboxylation capacity (Vcmax ) at 25°C (Rd,25 , Vcmax,25 ) are coordinated so that Rd,25 variations support Vcmax,25 at a level allowing full light use, with Vcmax,25 reflecting daytime conditions (for photosynthesis), and Rd,25 /Vcmax,25 reflecting night-time conditions (for starch degradation and sucrose export). We tested this hypothesis temporally using a 5-yr warming experiment, and spatially using an extensive field-measurement data set. We compared the results to three published alternatives: Rd,25 declines linearly with daily average prior temperature; Rd at average prior night temperatures tends towards a constant value; and Rd,25 /Vcmax,25 is constant. Our hypothesis accounted for more variation in observed Rd,25 over time (R2 = 0.74) and space (R2 = 0.68) than the alternatives. Night-time temperature dominated the seasonal time-course of Rd , with an apparent response time scale of c. 2 wk. Vcmax dominated the spatial patterns. Our acclimation hypothesis results in a smaller increase in global Rd in response to rising CO2 and warming than is projected by the two of three alternative hypotheses, and by current models.
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Affiliation(s)
- Yanghang Ren
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
| | - Han Wang
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
| | - Sandy P Harrison
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
- School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading, Reading, RG6 6AH, UK
| | - I Colin Prentice
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, 100084, China
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 46, Canberra, ACT, 2601, Australia
| | - Nicholas G Smith
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Giulia Mengoli
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
- Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2753, Australia
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Rhyner TMY, Bröder L, White ME, Mittelbach BVA, Brunmayr A, Hagedorn F, Storck FR, Passera L, Haghipour N, Zobrist J, Eglinton TI. Radiocarbon signatures of carbon phases exported by Swiss rivers in the Anthropocene. Philos Trans A Math Phys Eng Sci 2023; 381:20220326. [PMID: 37807683 PMCID: PMC10642794 DOI: 10.1098/rsta.2022.0326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 09/06/2023] [Indexed: 10/10/2023]
Abstract
Lateral carbon transport through the land-to-ocean-aquatic-continuum (LOAC) represents a key component of the global carbon cycle. This LOAC involves complex processes, many of which are prone to anthropogenic perturbation, yet the influence of natural and human-induced drivers remains poorly constrained. This study examines the radiocarbon (14C) signatures of particulate and dissolved organic carbon (POC, DOC) and dissolved inorganic carbon (DIC) transported by Swiss rivers to assess controls on sources and cycling of carbon within their watersheds. Twenty-one rivers were selected and sampled during high-flow conditions in summer 2021, a year of exceptionally high rainfall. Δ14C values of POC range from -446‰ to -158‰, while corresponding ranges of Δ14C values for DOC and DIC are -377‰ to -43‰ and -301‰ to -40‰, respectively, indicating the prevalence of pre-aged carbon. Region-specific agricultural practices seem to have an influential effect on all three carbon phases in rivers draining the Swiss Plateau. Based on Multivariate Regression Analysis, mean basin elevation correlated negatively with Δ14C values of all three carbon phases. These contrasts between alpine terrain and the lowlands reflect the importance of overriding ecoregional controls on riverine carbon dynamics within Switzerland, despite high spatial variability in catchment properties. This article is part of the Theo Murphy meeting issue 'Radiocarbon in the Anthropocene'.
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Affiliation(s)
| | - Lisa Bröder
- Geological Institute, ETH Zürich, 8092 Zürich, Switzerland
| | | | | | | | - Frank Hagedorn
- Swiss Federal Institute for Forest, Snow, and Landscape Research, 8903 Birmensdorf, Switzerland
| | - Florian R. Storck
- Hydrology Division, Federal Office for the Environment, 3003 Bern, Switzerland
| | - Lucas Passera
- Hydrology Division, Federal Office for the Environment, 3003 Bern, Switzerland
| | - Negar Haghipour
- Geological Institute, ETH Zürich, 8092 Zürich, Switzerland
- Department of Physics, Laboratory of Ion Beam Physics,8093 Zürich, Switzerland
| | - Juerg Zobrist
- Emeritus Scientist, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
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6
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Sierra CA, Quetin GR, Metzler H, Müller M. A decrease in the age of respired carbon from the terrestrial biosphere and increase in the asymmetry of its distribution. Philos Trans A Math Phys Eng Sci 2023; 381:20220200. [PMID: 37807689 PMCID: PMC10642774 DOI: 10.1098/rsta.2022.0200] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/02/2023] [Indexed: 10/10/2023]
Abstract
We provide here a model-based estimate of the transit time of carbon through the terrestrial biosphere, since the time of carbon uptake through photosynthesis until its release through respiration. We explored the consequences of increasing productivity versus increasing respiration rates on the transit time distribution and found that while higher respiration rates induced by higher temperature increase the transit time because older carbon is respired, increases in productivity cause a decline in transit times because more young carbon is available to supply increased metabolism. The combined effect of increases in temperature and productivity results in a decrease in transit times, with the productivity effect dominating over the respiration effect. By using an ensemble of simulation trajectories from the Carbon Data Model Framework (CARDAMOM), we obtained time-dependent transit time distributions incorporating the twentieth century global change. In these simulations, transit time declined over the twentieth century, suggesting an increased productivity effect that augmented the amount of respired young carbon, but also increasing the release of old carbon from high latitudes. The transit time distribution of carbon becomes more asymmetric over time, with more carbon transiting faster through tropical and temperate regions, and older carbon being respired from high latitude regions. This article is part of the Theo Murphy meeting issue 'Radiocarbon in the Anthropocene'.
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Affiliation(s)
- Carlos A. Sierra
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena 07745, Germany
| | - Gregory R. Quetin
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
- Department of Geography, University of California, Santa Barbara, CA 93106, USA
| | - Holger Metzler
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena 07745, Germany
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala 75651, Sweden
| | - Markus Müller
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena 07745, Germany
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, USA
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7
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Lu J, Tang J, Shan R, Li G, Rao P, Zhang N. Spatiotemporal analysis of the future carbon footprint of solar electricity in the United States by a dynamic life cycle assessment. iScience 2023; 26:106188. [PMID: 36879802 PMCID: PMC9985043 DOI: 10.1016/j.isci.2023.106188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/15/2022] [Accepted: 02/07/2023] [Indexed: 02/15/2023] Open
Abstract
Solar photovoltaics (PVs) installation would increase 20-fold by 2050; however, considerable greenhouse gas (GHG) emissions are generated during the cradle-to-gate production, with spatiotemporal variances depending on the grid emission. Thus, a dynamic life cycle assessment (LCA) model was developed to assess the accumulated PV panels with a heterogeneous carbon footprint if manufactured and installed in the United States. The state-level carbon footprint of solar electricity (CFE PV-avg) from 2022 to 2050 was estimated using several cradle-to-gate production scenarios to account for emissions stemming from electricity generated from solar PVs. The CFE PV-avg (min 0.032, max 0.051, weighted avg. 0.040 kg CO2-eq/kWh) in 2050 will be significantly lower than that of the comparison benchmark (min 0.047, max 0.068, weighted avg. 0.056 kg CO2-eq/kWh). The proposed dynamic LCA framework is promising for planning solar PV supply chains and, ultimately, the supply chain of an entire carbon-neutral energy system to maximize the environmental benefits.
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Affiliation(s)
- Jiaqi Lu
- Innovation Centre for Environment and Resources, Shanghai University of Engineering Science, No.333 Longteng Road, Songjiang District, Shanghai 201620, China.,Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Jing Tang
- Innovation Centre for Environment and Resources, Shanghai University of Engineering Science, No.333 Longteng Road, Songjiang District, Shanghai 201620, China
| | - Rui Shan
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Carbon Baseline LLC, Shanghai 200071, China
| | - Guanghui Li
- Innovation Centre for Environment and Resources, Shanghai University of Engineering Science, No.333 Longteng Road, Songjiang District, Shanghai 201620, China
| | - Pinhua Rao
- Innovation Centre for Environment and Resources, Shanghai University of Engineering Science, No.333 Longteng Road, Songjiang District, Shanghai 201620, China
| | - Nan Zhang
- Centre for Process Integration, Department of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, UK
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8
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Maschler J, Bialic‐Murphy L, Wan J, Andresen LC, Zohner CM, Reich PB, Lüscher A, Schneider MK, Müller C, Moser G, Dukes JS, Schmidt IK, Bilton MC, Zhu K, Crowther TW. Links across ecological scales: Plant biomass responses to elevated CO 2. Glob Chang Biol 2022; 28:6115-6134. [PMID: 36069191 PMCID: PMC9825951 DOI: 10.1111/gcb.16351] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/06/2022] [Indexed: 06/04/2023]
Abstract
The degree to which elevated CO2 concentrations (e[CO2 ]) increase the amount of carbon (C) assimilated by vegetation plays a key role in climate change. However, due to the short-term nature of CO2 enrichment experiments and the lack of reconciliation between different ecological scales, the effect of e[CO2 ] on plant biomass stocks remains a major uncertainty in future climate projections. Here, we review the effect of e[CO2 ] on plant biomass across multiple levels of ecological organization, scaling from physiological responses to changes in population-, community-, ecosystem-, and global-scale dynamics. We find that evidence for a sustained biomass response to e[CO2 ] varies across ecological scales, leading to diverging conclusions about the responses of individuals, populations, communities, and ecosystems. While the distinct focus of every scale reveals new mechanisms driving biomass accumulation under e[CO2 ], none of them provides a full picture of all relevant processes. For example, while physiological evidence suggests a possible long-term basis for increased biomass accumulation under e[CO2 ] through sustained photosynthetic stimulation, population-scale evidence indicates that a possible e[CO2 ]-induced increase in mortality rates might potentially outweigh the effect of increases in plant growth rates on biomass levels. Evidence at the global scale may indicate that e[CO2 ] has contributed to increased biomass cover over recent decades, but due to the difficulty to disentangle the effect of e[CO2 ] from a variety of climatic and land-use-related drivers of plant biomass stocks, it remains unclear whether nutrient limitations or other ecological mechanisms operating at finer scales will dampen the e[CO2 ] effect over time. By exploring these discrepancies, we identify key research gaps in our understanding of the effect of e[CO2 ] on plant biomass and highlight the need to integrate knowledge across scales of ecological organization so that large-scale modeling can represent the finer-scale mechanisms needed to constrain our understanding of future terrestrial C storage.
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Affiliation(s)
- Julia Maschler
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Lalasia Bialic‐Murphy
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Joe Wan
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | | | - Constantin M. Zohner
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Peter B. Reich
- Department of Forest ResourcesUniversity of MinnesotaSt. PaulMinnesotaUSA
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
- Institute for Global Change Biology, and School for the Environment and SustainabilityUniversity of MichiganAnn ArborMichiganUSA
| | - Andreas Lüscher
- ETH ZurichInstitute of Agricultural ScienceZurichSwitzerland
- Agroscope, Forage Production and Grassland SystemsZurichSwitzerland
| | - Manuel K. Schneider
- ETH ZurichInstitute of Agricultural ScienceZurichSwitzerland
- Agroscope, Forage Production and Grassland SystemsZurichSwitzerland
| | - Christoph Müller
- Institute of Plant EcologyJustus Liebig UniversityGiessenGermany
- School of Biology and Environmental Science and Earth InstituteUniversity College DublinDublinIreland
| | - Gerald Moser
- Institute of Plant EcologyJustus Liebig UniversityGiessenGermany
| | - Jeffrey S. Dukes
- Department of Forestry and Natural ResourcesPurdue UniversityWest LafayetteIndianaUSA
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
- Department of Global EcologyCarnegie Institution for ScienceStanfordCaliforniaUSA
| | - Inger Kappel Schmidt
- Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| | - Mark C. Bilton
- Department of Agriculture and Natural Resources SciencesNamibia University of Science and Technology (NUST)WindhoekNamibia
| | - Kai Zhu
- Department of Environmental StudiesUniversity of CaliforniaSanta CruzCaliforniaUSA
| | - Thomas W. Crowther
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
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Moya MR, López‐Ballesteros A, Sánchez‐Cañete EP, Serrano‐Ortiz P, Oyonarte C, Domingo F, Kowalski A. Ecosystem CO 2 release driven by wind occurs in drylands at global scale. Glob Chang Biol 2022; 28:5320-5333. [PMID: 35727701 PMCID: PMC9545467 DOI: 10.1111/gcb.16277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 04/12/2022] [Indexed: 06/15/2023]
Abstract
Subterranean ventilation is a non-diffusive transport process that provokes the abrupt transfer of CO2 -rich air (previously stored) through water-free soil pores and cracks from the vadose zone to the atmosphere, under high-turbulence conditions. In dryland ecosystems, whose biological carbon exchanges are poorly characterized, it can strongly determine eddy-covariance CO2 fluxes that are used to validate remote sensing products and constrain models of gross primary productivity. Although subterranean ventilation episodes (VE) may occur in arid and semi-arid regions, which are unsung players in the global carbon cycle, little research has focused on the role of VE CO2 emissions in land-atmosphere CO2 exchange. This study shows clear empirical evidence of globally occurring VE. To identify VE, we used in situ quality-controlled eddy-covariance open data of carbon fluxes and ancillary variables from 145 sites in different open land covers (grassland, cropland, shrubland, savanna, and barren) across the globe. We selected the analyzed database from the FLUXNET2015, AmeriFlux, OzFlux, and AsiaFlux networks. To standardize the analysis, we designed an algorithm to detect CO2 emissions produced by VE at all sites considered in this study. Its main requirement is the presence of considerable and non-spurious correlation between the friction velocity (i.e., turbulence) and CO2 emissions. Of the sites analyzed, 34% exhibited the occurrence of VE. This vented CO2 emerged mainly from arid ecosystems (84%) and sites with hot and dry periods. Despite some limitations in data availability, this research demonstrates that VE-driven CO2 emissions occur globally. Future research should seek a better understanding of its drivers and the improvement of partitioning models, to reduce uncertainties in estimated biological CO2 exchanges and infer their contribution to the global net ecosystem carbon balance.
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Affiliation(s)
- María Rosario Moya
- Experimental Station of Arid Zones (EEZA‐CSIC), Desertification and GeoecologyAlmeríaSpain
| | - Ana López‐Ballesteros
- Basque Centre for Climate Change (BC3)Scientific Campus of the University of the Basque CountryLeioaSpain
- Department of Agricultural and Forest Systems and the EnvironmentAgrifood Research and Technology Centre of Aragon (CITA)ZaragozaSpain
| | - Enrique P. Sánchez‐Cañete
- Applied PhysicsUniversity of Granada (UGR)GranadaSpain
- Inter‐University Institute for Earth System Research (IISTA‐CEAMA)GranadaSpain
| | - Penélope Serrano‐Ortiz
- Inter‐University Institute for Earth System Research (IISTA‐CEAMA)GranadaSpain
- EcologyUniversity of Granada (UGR)GranadaSpain
| | - Cecilio Oyonarte
- AgronomyUniversity of Almeria (UAL)AlmeríaSpain
- Andalusian Center for the Assessment and Monitoring of Global Change (CAESCG)AlmeríaSpain
| | - Francisco Domingo
- Experimental Station of Arid Zones (EEZA‐CSIC), Desertification and GeoecologyAlmeríaSpain
| | - Andrew S. Kowalski
- Applied PhysicsUniversity of Granada (UGR)GranadaSpain
- Inter‐University Institute for Earth System Research (IISTA‐CEAMA)GranadaSpain
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10
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Lacroix F, Ilyina T, Mathis M, Laruelle GG, Regnier P. Historical increases in land-derived nutrient inputs may alleviate effects of a changing physical climate on the oceanic carbon cycle. Glob Chang Biol 2021; 27:5491-5513. [PMID: 34351039 DOI: 10.1111/gcb.15822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The implications of climate change and other human perturbations on the oceanic carbon cycle are still associated with large uncertainties. Global-scale modelling studies are essential to investigate anthropogenic perturbations of oceanic carbon fluxes but, until now, they have not considered the impacts of temporal changes in riverine and atmospheric inputs of P and N on the marine net biological productivity (NPP) and air-sea CO2 exchange (FCO2 ). To address this, we perform a series of simulations using an enhanced version of the global ocean biogeochemistry model HAMOCC to isolate effects arising from (1) increasing atmospheric CO2 levels, (2) a changing physical climate and (3) alterations in inputs of terrigenous P and N on marine carbon cycling over the 1905-2010 period. Our simulations reveal that our first-order approximation of increased terrigenous nutrient inputs causes an enhancement of 2.15 Pg C year-1 of the global marine NPP, a relative increase of +5% over the simulation period. This increase completely compensates the simulated NPP decrease as a result of increased upper ocean stratification of -3% in relative terms. The coastal ocean undergoes a global relative increase of 14% in NPP arising largely from increased riverine inputs, with regional increases exceeding 100%, for instance on the shelves of the Bay of Bengal. The imprint of enhanced terrigenous nutrient inputs is also simulated further offshore, inducing a 1.75 Pg C year-1 (+4%) enhancement of the NPP in the open ocean. This finding implies that the perturbation of carbon fluxes through coastal eutrophication may extend further offshore than that was previously assumed. While increased nutrient inputs are the largest driver of change for the CO2 uptake at the regional scale and enhance the global coastal ocean CO2 uptake by 0.02 Pg C year-1 , they only marginally affect the FCO2 of the open ocean over our study's timeline.
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Affiliation(s)
- Fabrice Lacroix
- Biogeochemical Signals (BSI), Max Planck Institute for Biogeochemistry, Jena, Germany
- Ocean in the Earth System (OES), Max Planck Institute for Meteorology, Hamburg, Germany
- Biogeochemistry & Modeling of the Earth System, Department Geoscience, Environment & Society (DGES), Université Libre de Bruxelles, Brussels, Belgium
| | - Tatiana Ilyina
- Ocean in the Earth System (OES), Max Planck Institute for Meteorology, Hamburg, Germany
| | - Moritz Mathis
- Institute of Coastal Systems Analysis and Modeling, Heimholz-Zentrum Geesthacht, Geesthacht, Germany
| | - Goulven G Laruelle
- Biogeochemistry & Modeling of the Earth System, Department Geoscience, Environment & Society (DGES), Université Libre de Bruxelles, Brussels, Belgium
| | - Pierre Regnier
- Biogeochemistry & Modeling of the Earth System, Department Geoscience, Environment & Society (DGES), Université Libre de Bruxelles, Brussels, Belgium
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11
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Abstract
The conversion of CO2 to value-added products powered with solar energy is an ideal solution to establishing a closed carbon cycle. Combining microorganisms with light-harvesting nanomaterials into photosynthetic biohybrid systems (PBSs) presents an approach to reaching this solution. Metabolic pathways precisely evolved for CO2 fixation selectively and reliably generate products. Nanomaterials harvest solar light and biocompatibly associate with microorganisms owing to similar lengths scales. Although this is a nascent field, a variety of approaches have been implemented encompassing different microorganisms and nanomaterials. To advance the field in an impactful manner, it is paramount to understand the molecular underpinnings of PBSs. In this perspective, we highlight studies inspecting charge uptake pathways and singularities in photosensitized cells. We discuss further analyses to more completely elucidate these constructs, and we focus on criteria to be met for designing photosensitizing nanomaterials. As a result, we advocate for the pairing of microorganisms with naturally occurring and highly biocompatible mineral-based semiconductor nanomaterials.
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Affiliation(s)
| | - Ji Min Kim
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | | | | | - Peidong Yang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy NanoScience Institute at the University of California, Berkeley, CA, USA
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12
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Walker AP, De Kauwe MG, Bastos A, Belmecheri S, Georgiou K, Keeling RF, McMahon SM, Medlyn BE, Moore DJP, Norby RJ, Zaehle S, Anderson-Teixeira KJ, Battipaglia G, Brienen RJW, Cabugao KG, Cailleret M, Campbell E, Canadell JG, Ciais P, Craig ME, Ellsworth DS, Farquhar GD, Fatichi S, Fisher JB, Frank DC, Graven H, Gu L, Haverd V, Heilman K, Heimann M, Hungate BA, Iversen CM, Joos F, Jiang M, Keenan TF, Knauer J, Körner C, Leshyk VO, Leuzinger S, Liu Y, MacBean N, Malhi Y, McVicar TR, Penuelas J, Pongratz J, Powell AS, Riutta T, Sabot MEB, Schleucher J, Sitch S, Smith WK, Sulman B, Taylor B, Terrer C, Torn MS, Treseder KK, Trugman AT, Trumbore SE, van Mantgem PJ, Voelker SL, Whelan ME, Zuidema PA. Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO 2. New Phytol 2021; 229:2413-2445. [PMID: 32789857 DOI: 10.1111/nph.16866] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/06/2020] [Indexed: 05/22/2023]
Abstract
Atmospheric carbon dioxide concentration ([CO2 ]) is increasing, which increases leaf-scale photosynthesis and intrinsic water-use efficiency. These direct responses have the potential to increase plant growth, vegetation biomass, and soil organic matter; transferring carbon from the atmosphere into terrestrial ecosystems (a carbon sink). A substantial global terrestrial carbon sink would slow the rate of [CO2 ] increase and thus climate change. However, ecosystem CO2 responses are complex or confounded by concurrent changes in multiple agents of global change and evidence for a [CO2 ]-driven terrestrial carbon sink can appear contradictory. Here we synthesize theory and broad, multidisciplinary evidence for the effects of increasing [CO2 ] (iCO2 ) on the global terrestrial carbon sink. Evidence suggests a substantial increase in global photosynthesis since pre-industrial times. Established theory, supported by experiments, indicates that iCO2 is likely responsible for about half of the increase. Global carbon budgeting, atmospheric data, and forest inventories indicate a historical carbon sink, and these apparent iCO2 responses are high in comparison to experiments and predictions from theory. Plant mortality and soil carbon iCO2 responses are highly uncertain. In conclusion, a range of evidence supports a positive terrestrial carbon sink in response to iCO2 , albeit with uncertain magnitude and strong suggestion of a role for additional agents of global change.
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Affiliation(s)
- Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Martin G De Kauwe
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
- Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ana Bastos
- Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333, Germany
| | - Soumaya Belmecheri
- Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721, USA
| | - Katerina Georgiou
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
| | - Ralph F Keeling
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92093, USA
| | - Sean M McMahon
- Smithsonian Environmental Research Center, Edgewater, MD, 21037, USA
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David J P Moore
- School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721, USA
| | - Richard J Norby
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Sönke Zaehle
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745, Germany
| | - Kristina J Anderson-Teixeira
- Conservation Ecology Center, Smithsonian Conservation Biology Institute, MRC 5535, Front Royal, VA, 22630, USA
- Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Panama City, Panama
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania, Caserta, 81100, Italy
| | | | - Kristine G Cabugao
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Maxime Cailleret
- INRAE, UMR RECOVER, Aix-Marseille Université, 3275 route de Cézanne, Aix-en-Provence Cedex 5, 13182, France
- Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Elliott Campbell
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Josep G Canadell
- CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, F-91191, France
| | - Matthew E Craig
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Graham D Farquhar
- Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Simone Fatichi
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576, Singapore
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini Platz 5, Zurich, 8093, Switzerland
| | - Joshua B Fisher
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA, 91109, USA
| | - David C Frank
- Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721, USA
| | - Heather Graven
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Lianhong Gu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Vanessa Haverd
- CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Kelly Heilman
- Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721, USA
| | - Martin Heimann
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745, Germany
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Colleen M Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Fortunat Joos
- Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstr. 5, Bern, CH-3012, Switzerland
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Trevor F Keenan
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, 94720, USA
- Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720, USA
| | - Jürgen Knauer
- CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Christian Körner
- Department of Environmental Sciences, Botany, University of Basel, Basel, 4056, Switzerland
| | - Victor O Leshyk
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Sebastian Leuzinger
- School of Science, Auckland University of Technology, Auckland, 1142, New Zealand
| | - Yao Liu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Natasha MacBean
- Department of Geography, Indiana University, Bloomington, IN, 47405, USA
| | - Yadvinder Malhi
- School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | - Tim R McVicar
- CSIRO Land and Water, GPO Box 1700, Canberra, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Climate Extremes, 142 Mills Rd, Australian National University, Canberra, ACT, 2601, Australia
| | - Josep Penuelas
- CSIC, Global Ecology CREAF-CSIC-UAB, Bellaterra, Barcelona, Catalonia, 08193, Spain
- CREAF, Cerdanyola del Vallès, Barcelona, Catalonia, 08193, Spain
| | - Julia Pongratz
- Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333, Germany
- Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg, Germany
| | - A Shafer Powell
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Terhi Riutta
- School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | - Manon E B Sabot
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
- Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Juergen Schleucher
- Department of Medical Biochemistry & Biophysics, Umeå University, Umea, 901 87, Sweden
| | - Stephen Sitch
- College of Life and Environmental Sciences, University of Exeter, Exeter, Laver Building, EX4 4QF, UK
| | - William K Smith
- School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721, USA
| | - Benjamin Sulman
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Benton Taylor
- Smithsonian Environmental Research Center, Edgewater, MD, 21037, USA
| | - César Terrer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Margaret S Torn
- Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720, USA
| | - Kathleen K Treseder
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA, 92697, USA
| | - Anna T Trugman
- Department of Geography, 1832 Ellison Hall, Santa Barbara, CA, 93016, USA
| | - Susan E Trumbore
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745, Germany
| | | | - Steve L Voelker
- Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA
| | - Mary E Whelan
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ, 08901, USA
| | - Pieter A Zuidema
- Forest Ecology and Forest Management group, Wageningen University, PO Box 47, Wageningen, 6700 AA, the Netherlands
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13
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Storm MS, Hesselbo SP, Jenkyns HC, Ruhl M, Ullmann CV, Xu W, Leng MJ, Riding JB, Gorbanenko O. Orbital pacing and secular evolution of the Early Jurassic carbon cycle. Proc Natl Acad Sci U S A 2020; 117:3974-82. [PMID: 32041889 DOI: 10.1073/pnas.1912094117] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cyclic variations in Earth’s orbit drive periodic changes in the ocean–atmosphere system at a time scale of tens to hundreds of thousands of years. The Mochras δ13CTOC record illustrates the continued impact of long-eccentricity (405-ky) orbital forcing on the carbon cycle over at least ∼18 My of Early Jurassic time and emphasizes orbital forcing as a driving mechanism behind medium-amplitude δ13C fluctuations superimposed on larger-scale trends that are driven by other variables such as tectonically determined paleogeography and eruption of large igneous provinces. The dataset provides a framework for distinguishing between internal Earth processes and solar-system dynamics as the driving mechanism for Early Jurassic δ13C fluctuations and provides an astronomical time scale for the Sinemurian Stage. Global perturbations to the Early Jurassic environment (∼201 to ∼174 Ma), notably during the Triassic–Jurassic transition and Toarcian Oceanic Anoxic Event, are well studied and largely associated with volcanogenic greenhouse gas emissions released by large igneous provinces. The long-term secular evolution, timing, and pacing of changes in the Early Jurassic carbon cycle that provide context for these events are thus far poorly understood due to a lack of continuous high-resolution δ13C data. Here we present a δ13CTOC record for the uppermost Rhaetian (Triassic) to Pliensbachian (Lower Jurassic), derived from a calcareous mudstone succession of the exceptionally expanded Llanbedr (Mochras Farm) borehole, Cardigan Bay Basin, Wales, United Kingdom. Combined with existing δ13CTOC data from the Toarcian, the compilation covers the entire Lower Jurassic. The dataset reproduces large-amplitude δ13CTOC excursions (>3‰) recognized elsewhere, at the Sinemurian–Pliensbachian transition and in the lower Toarcian serpentinum zone, as well as several previously identified medium-amplitude (∼0.5 to 2‰) shifts in the Hettangian to Pliensbachian interval. In addition, multiple hitherto undiscovered isotope shifts of comparable amplitude and stratigraphic extent are recorded, demonstrating that those similar features described earlier from stratigraphically more limited sections are nonunique in a long-term context. These shifts are identified as long-eccentricity (∼405-ky) orbital cycles. Orbital tuning of the δ13CTOC record provides the basis for an astrochronological duration estimate for the Pliensbachian and Sinemurian, giving implications for the duration of the Hettangian Stage. Overall the chemostratigraphy illustrates particular sensitivity of the marine carbon cycle to long-eccentricity orbital forcing.
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14
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Bushinsky SM, Landschützer P, Rödenbeck C, Gray AR, Baker D, Mazloff MR, Resplandy L, Johnson KS, Sarmiento JL. Reassessing Southern Ocean Air-Sea CO 2 Flux Estimates With the Addition of Biogeochemical Float Observations. Global Biogeochem Cycles 2019; 33:1370-1388. [PMID: 32025087 PMCID: PMC6988491 DOI: 10.1029/2019gb006176] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 09/30/2019] [Accepted: 10/14/2019] [Indexed: 05/24/2023]
Abstract
New estimates of pCO2 from profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project have demonstrated the importance of wintertime outgassing south of the Polar Front, challenging the accepted magnitude of Southern Ocean carbon uptake (Gray et al., 2018, https://doi:10.1029/2018GL078013). Here, we put 3.5 years of SOCCOM observations into broader context with the global surface carbon dioxide database (Surface Ocean CO2 Atlas, SOCAT) by using the two interpolation methods currently used to assess the ocean models in the Global Carbon Budget (Le Quéré et al., 2018, https://doi:10.5194/essd-10-2141-2018) to create a ship-only, a float-weighted, and a combined estimate of Southern Ocean carbon fluxes (<35°S). In our ship-only estimate, we calculate a mean uptake of -1.14 ± 0.19 Pg C/yr for 2015-2017, consistent with prior studies. The float-weighted estimate yields a significantly lower Southern Ocean uptake of -0.35 ± 0.19 Pg C/yr. Subsampling of high-resolution ocean biogeochemical process models indicates that some of the differences between float and ship-only estimates of the Southern Ocean carbon flux can be explained by spatial and temporal sampling differences. The combined ship and float estimate minimizes the root-mean-square pCO2 difference between the mapped product and both data sets, giving a new Southern Ocean uptake of -0.75 ± 0.22 Pg C/yr, though with uncertainties that overlap the ship-only estimate. An atmospheric inversion reveals that a shift of this magnitude in the contemporary Southern Ocean carbon flux must be compensated for by ocean or land sinks within the Southern Hemisphere.
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Affiliation(s)
- Seth M. Bushinsky
- Program in Atmospheric and Oceanic SciencesPrinceton UniversityPrincetonNJUSA
- Now at Department of OceanographyUniversity of Hawai'i at MānoaHonoluluHIUSA
| | | | | | - Alison R. Gray
- School of OceanographyUniversity of WashingtonSeattleWAUSA
| | - David Baker
- Cooperative Institute for Research in the AtmosphereColorado State UniversityFort CollinsCOUSA
| | - Matthew R. Mazloff
- Scripps Institution of OceanographyUniversity of California, San DiegoLa JollaCAUSA
| | - Laure Resplandy
- Department of Geosciences and Princeton Environmental InstitutePrinceton UniversityPrincetonNJUSA
| | | | - Jorge L. Sarmiento
- Program in Atmospheric and Oceanic SciencesPrinceton UniversityPrincetonNJUSA
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15
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Alhassan AM, Ma W, Li G, Jiang Z, Wu J, Chen G. Response of soil organic carbon to vegetation degradation along a moisture gradient in a wet meadow on the Qinghai-Tibet Plateau. Ecol Evol 2018; 8:11999-12010. [PMID: 30598794 PMCID: PMC6303805 DOI: 10.1002/ece3.4656] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 08/29/2018] [Accepted: 10/01/2018] [Indexed: 11/19/2022] Open
Abstract
The study was conducted during the growing seasons of 2013, 2014, and 2015 in the wet meadows on the eastern Qinghai-Tibet plateau (QTP) in the Gansu Gahai Wetland Nature Reserve to determine the dynamics of soil organic carbon (SOC) as affected by vegetation degradation along a moisture gradient and to assess its relationship with other soil properties and biomass yield. Hence, we measured SOC at depths of 0-10, 10-20, and 20-40 cm under the influence of four categories of vegetation degradation (healthy vegetation [HV], slightly degraded [SD], moderately degraded [MD], and heavily degraded [HD]). Our results showed that SOC decreased with increased degree of vegetation degradation. Average SOC content ranged between 36.18 ± 4.06 g/kg in HD and 69.86 ± 21.78 g/kg in HV. Compared with HV, SOC content reduced by 30.49%, 42.22%, and 48.22% in SD, MD, and HD, respectively. SOC significantly correlated positively with soil water content, aboveground biomass, and belowground biomass, but significantly correlated negatively with soil temperature and bulk density (p < 0.05). Highly Significant positive correlations were also found between SOC and total nitrogen (p = 0.0036), total phosphorus (p = 0.0006) and total potassium (p < 0.0001). Our study suggests that severe vegetation and moisture loss led to approximately 50% loss in SOC content in the wet meadows, implying that under climate warming, vegetation and soil moisture loss will dramatically destabilize carbon sink capacities of wetlands. We therefore suggest wetland hydrological management, restoration of vegetation, plant species protection, regulation of grazing activities, and other anthropogenic activities to stabilize carbon sink capacities of wetlands.
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Affiliation(s)
| | - Weiwei Ma
- College of ForestryGansu Agricultural UniversityLanzhouChina
- Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
| | - Guang Li
- College of ForestryGansu Agricultural UniversityLanzhouChina
| | - Zhirong Jiang
- College of ForestryGansu Agricultural UniversityLanzhouChina
| | - Jiangqi Wu
- College of ForestryGansu Agricultural UniversityLanzhouChina
| | - Guopeng Chen
- College of ForestryGansu Agricultural UniversityLanzhouChina
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16
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Wiggins EB, Czimczik CI, Santos GM, Chen Y, Xu X, Holden SR, Randerson JT, Harvey CF, Kai FM, Yu LE. Smoke radiocarbon measurements from Indonesian fires provide evidence for burning of millennia-aged peat. Proc Natl Acad Sci U S A 2018; 115:12419-24. [PMID: 30455288 DOI: 10.1073/pnas.1806003115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In response to a strong El Niño, fires in Indonesia during September and October 2015 released a large amount of carbon dioxide and created a massive regional smoke cloud that severely degraded air quality in many urban centers across Southeast Asia. Although several lines of evidence indicate that peat burning was a dominant contributor to emissions in the region, El Niño-induced drought is also known to increase deforestation fires and agricultural waste burning in plantations. As a result, uncertainties remain with respect to partitioning emissions among different ecosystem and fire types. Here we measured the radiocarbon content (14C) of carbonaceous aerosol samples collected in Singapore from September 2014 through October 2015, with the aim of identifying the age and origin of fire-emitted fine particulate matter (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm). The Δ14C of fire-emitted aerosol was -76 ± 51‰, corresponding to a carbon pool of combusted organic matter with a mean turnover time of 800 ± 420 y. Our observations indicated that smoke plumes reaching Singapore originated primarily from peat burning (∼85%), and not from deforestation fires or waste burning. Atmospheric transport modeling confirmed that fires in Sumatra and Borneo were dominant contributors to elevated PM2.5 in Singapore during the fire season. The mean age of the carbonaceous aerosol, which predates the Industrial Revolution, highlights the importance of improving peatland fire management during future El Niño events for meeting climate mitigation and air quality commitments.
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17
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Affiliation(s)
- Assaf Gal
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
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18
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Zhang X, Wang YP, Peng S, Rayner PJ, Ciais P, Silver JD, Piao S, Zhu Z, Lu X, Zheng X. Dominant regions and drivers of the variability of the global land carbon sink across timescales. Glob Chang Biol 2018; 24:3954-3968. [PMID: 29665215 DOI: 10.1111/gcb.14275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 06/08/2023]
Abstract
Net biome productivity (NBP) dominates the observed large variation of atmospheric CO2 annual increase over the last five decades. However, the dominant regions controlling inter-annual to multi-decadal variability of global NBP are still controversial (semi-arid regions vs. temperate or tropical forests). By developing a theory for partitioning the variance of NBP into the contributions of net primary production (NPP) and heterotrophic respiration (Rh ) at different timescales, and using both observation-based atmospheric CO2 inversion product and the outputs of 10 process-based terrestrial ecosystem models forced by 110-year observational climate, we tried to reconcile the controversy by showing that semi-arid lands dominate the variability of global NBP at inter-annual (<10 years) and tropical forests dominate at multi-decadal scales (>30 years). Results further indicate that global NBP variability is dominated by the NPP component at inter-annual timescales, and is progressively controlled by Rh with increasing timescale. Multi-decadal NBP variations of tropical rainforests are modulated by the Pacific Decadal Oscillation (PDO) through its significant influences on both temperature and precipitation. This study calls for long-term observations for the decadal or longer fluctuations in carbon fluxes to gain insights on the future evolution of global NBP, particularly in the tropical forests that dominate the decadal variability of land carbon uptake and are more effective for climate mitigation.
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Affiliation(s)
- Xuanze Zhang
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Ying-Ping Wang
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- CSIRO Oceans and Atmosphere, Aspendale, VIC, Australia
| | - Shushi Peng
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Peter J Rayner
- School of Earth Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jeremy D Silver
- School of Earth Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Shilong Piao
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Tibetan Plateau Earth Science, Chinese Academy of Sciences, Beijing, China
| | - Zaichun Zhu
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Xingjie Lu
- Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma
| | - Xiaogu Zheng
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
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19
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da Silva Carvalho LC, Fearnside PM, Nascimento MT, Barbosa RI. Amazon soil charcoal: Pyrogenic carbon stock depends of ignition source distance and forest type in Roraima, Brazil. Glob Chang Biol 2018; 24:4122-4130. [PMID: 29668042 DOI: 10.1111/gcb.14277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 03/16/2018] [Indexed: 06/08/2023]
Abstract
Pyrogenic carbon (PyC) derived from charcoal particles (paleo + modern) deposited in the soil column has been little studied in the Amazon, and our understanding of the factors that control the spatial and vertical distribution of these materials in the region's forest soils is still unclear. The objective of this study was to test the effect of forest type and distance from the ignition source on the PyC stocks contained in macroscopic particles of soil charcoal (≥2 mm; 1 m depth) dispersed in ecotone forests of the northern Brazilian Amazon. Thirty permanent plots were set up near a site that had been occupied by pre-Columbian and by modern populations until the late 1970s. The sampled plots represent seasonal and ombrophilous forests that occur under different hydro-edaphic restrictions. Our results indicate that the largest PyC stock was spatially dependent on distance to the ignition source (<3 km), occurring mainly in flood-free ombrophilous forests (3.46 ± 5.22 Mg PyC/ha). The vertical distribution of PyC in the deeper layers of the soil (> 50 cm) in seasonal forests was limited by hydro-edaphic impediments that restricted the occurrence of charcoal. These results suggest that PyC stocks derived from macroscopic charcoal particles in the soil of this Brazilian Amazon ecotone region are controlled by the distance from the ignition source of the fire, and that forest types with higher hydro-edaphic restrictions can inhibit formation and accumulation of charcoal. Making use of these distinctions reduces uncertainty and improves our ability to understand the variability of PyC stocks in forests with a history of fire in the Amazon.
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Affiliation(s)
- Lidiany C da Silva Carvalho
- Post-graduate Program in Natural Resources (PRONAT), Federal University of Roraima (UFRR), Boa Vista, Brazil
| | - Philip M Fearnside
- Department of Environmental Dynamics, National Institute for Research in Amazonia (INPA), Manaus, Brazil
| | - Marcelo T Nascimento
- Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Reinaldo I Barbosa
- Department of Environmental Dynamics, Roraima Office (NPRR), National Institute for Research in Amazonia (INPA), Boa Vista, Brazil
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Hursh A, Ballantyne A, Cooper L, Maneta M, Kimball J, Watts J. The sensitivity of soil respiration to soil temperature, moisture, and carbon supply at the global scale. Glob Chang Biol 2017; 23:2090-2103. [PMID: 27594213 DOI: 10.1111/gcb.13489] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 07/17/2016] [Indexed: 05/05/2023]
Abstract
Soil respiration (Rs) is a major pathway by which fixed carbon in the biosphere is returned to the atmosphere, yet there are limits to our ability to predict respiration rates using environmental drivers at the global scale. While temperature, moisture, carbon supply, and other site characteristics are known to regulate soil respiration rates at plot scales within certain biomes, quantitative frameworks for evaluating the relative importance of these factors across different biomes and at the global scale require tests of the relationships between field estimates and global climatic data. This study evaluates the factors driving Rs at the global scale by linking global datasets of soil moisture, soil temperature, primary productivity, and soil carbon estimates with observations of annual Rs from the Global Soil Respiration Database (SRDB). We find that calibrating models with parabolic soil moisture functions can improve predictive power over similar models with asymptotic functions of mean annual precipitation. Soil temperature is comparable with previously reported air temperature observations used in predicting Rs and is the dominant driver of Rs in global models; however, within certain biomes soil moisture and soil carbon emerge as dominant predictors of Rs. We identify regions where typical temperature-driven responses are further mediated by soil moisture, precipitation, and carbon supply and regions in which environmental controls on high Rs values are difficult to ascertain due to limited field data. Because soil moisture integrates temperature and precipitation dynamics, it can more directly constrain the heterotrophic component of Rs, but global-scale models tend to smooth its spatial heterogeneity by aggregating factors that increase moisture variability within and across biomes. We compare statistical and mechanistic models that provide independent estimates of global Rs ranging from 83 to 108 Pg yr-1 , but also highlight regions of uncertainty where more observations are required or environmental controls are hard to constrain.
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Affiliation(s)
- Andrew Hursh
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Ashley Ballantyne
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Leila Cooper
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Marco Maneta
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - John Kimball
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Jennifer Watts
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
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Haverd V, Ahlström A, Smith B, Canadell JG. Carbon cycle responses of semi-arid ecosystems to positive asymmetry in rainfall. Glob Chang Biol 2017; 23:793-800. [PMID: 27392297 DOI: 10.1111/gcb.13412] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
Recent evidence shows that warm semi-arid ecosystems are playing a disproportionate role in the interannual variability and greening trend of the global carbon cycle given their mean lower productivity when compared with other biomes (Ahlström et al. 2015 Science, 348, 895). Using multiple observations (land-atmosphere fluxes, biomass, streamflow and remotely sensed vegetation cover) and two state-of-the-art biospheric models, we show that climate variability and extremes lead to positive or negative responses in the biosphere, depending on vegetation type. We find Australia to be a global hot spot for variability, with semi-arid ecosystems in that country exhibiting increased carbon uptake due to both asymmetry in the interannual distribution of rainfall (extrinsic forcing), and asymmetry in the response of gross primary production (GPP) to rainfall change (intrinsic response). The latter is attributable to the pulse-response behaviour of the drought-adapted biota of these systems, a response that is estimated to be as much as half of that from the CO2 fertilization effect during 1990-2013. Mesic ecosystems, lacking drought-adapted species, did not show an intrinsic asymmetric response. Our findings suggest that a future more variable climate will induce large but contrasting ecosystem responses, differing among biomes globally, independent of changes in mean precipitation alone. The most significant changes are occurring in the extensive arid and semi-arid regions, and we suggest that the reported increased carbon uptake in response to asymmetric responses might be contributing to the observed greening trends there.
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Affiliation(s)
- Vanessa Haverd
- CSIRO Oceans and Atmosphere, GPO Box 3023, Canberra, ACT, 2601, Australia
| | - Anders Ahlström
- Department of Earth System Science, School of Earth, Energy and Environmental Sciences, Stanford University, Stanford, CA, 94305, USA
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, 223 62, Sweden
| | - Benjamin Smith
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, 223 62, Sweden
| | - Josep G Canadell
- CSIRO Oceans and Atmosphere, GPO Box 3023, Canberra, ACT, 2601, Australia
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Abstract
Since preindustrial times, the ocean has removed from the atmosphere 41% of the carbon emitted by human industrial activities. Despite significant uncertainties, the balance of evidence indicates that the globally integrated rate of ocean carbon uptake is increasing in response to increasing atmospheric CO2 concentrations. The El Niño-Southern Oscillation in the equatorial Pacific dominates interannual variability of the globally integrated sink. Modes of climate variability in high latitudes are correlated with variability in regional carbon sinks, but mechanistic understanding is incomplete. Regional sink variability, combined with sparse sampling, means that the growing oceanic sink cannot yet be directly detected from available surface data. Accurate and precise shipboard observations need to be continued and increasingly complemented with autonomous observations. These data, together with a variety of mechanistic and diagnostic models, are needed for better understanding, long-term monitoring, and future projections of this critical climate regulation service.
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Affiliation(s)
- Galen A McKinley
- Department of Atmospheric and Oceanic Sciences, Center for Climatic Research, and Space Science and Engineering Center, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
| | - Amanda R Fay
- Department of Atmospheric and Oceanic Sciences, Center for Climatic Research, and Space Science and Engineering Center, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
| | - Nicole S Lovenduski
- Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado 80309;
| | - Darren J Pilcher
- Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, Washington 98115;
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Abstract
Carbon preservation in marine sediments, supplemented by that in large lakes, is the primary mechanism that moves carbon from the active surficial carbon cycle to the slower geologic carbon cycle. Preservation rates are low relative to the rates at which carbon moves between surface pools, which has led to the preservation term largely being ignored when evaluating anthropogenic forcing of the global carbon cycle. However, a variety of anthropogenic drivers-including ocean warming, deoxygenation, and acidification, as well as human-induced changes in sediment delivery to the ocean and mixing and irrigation of continental margin sediments-all work to decrease the already small carbon preservation term. These drivers affect the cycling of both carbonate and organic carbon in the ocean. The overall effect of anthropogenic forcing in the modern ocean is to decrease delivery of carbon to sediments, increase sedimentary dissolution and remineralization, and subsequently decrease overall carbon preservation.
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Affiliation(s)
- Richard Keil
- School of Oceanography, University of Washington, Seattle, Washington 98195-5351;
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24
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Abstract
Climate and carbon cycle are tightly coupled on many timescales, from interannual to multi-millennial timescales. Observations always evidence a positive feedback, warming leading to release of carbon to the atmosphere; however, the processes at play differ depending on the timescales. State-of-the-art Earth System Models now represent these climate-carbon cycle feedbacks, always simulating a positive feedback over the twentieth and twenty-first centuries, although with substantial uncertainty. Recent studies now help to reduce this uncertainty. First, on short timescales, El Niño years record larger than average atmospheric CO2 growth rate, with tropical land ecosystems being the main drivers. These climate-carbon cycle anomalies can be used as emerging constraint on the tropical land carbon response to future climate change. Second, centennial variability found in last millennium records can be used to constrain the overall global carbon cycle response to climatic excursions. These independent methods point to climate-carbon cycle feedback at the low-end of the Earth System Models range, indicating that these models overestimate the carbon cycle sensitivity to climate change. These new findings also help to attribute the historical land and ocean carbon sinks to increase in atmospheric CO2 and climate change.
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Affiliation(s)
- Pierre Friedlingstein
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QE, UK
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25
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Billings SA, Schlesinger WH. Letter to the Editor on 'Pyrogenic organic matter production from wildfires: a missing sink in the global carbon cycle'. Glob Chang Biol 2015; 21:2831. [PMID: 25510226 DOI: 10.1111/gcb.12836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 12/08/2014] [Indexed: 06/04/2023]
Affiliation(s)
- Sharon A Billings
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
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26
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Abstract
The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, though a major component of the global carbon cycle, its source is not yet well understood. A key element of the carbon cycle is the microbial conversion of DOC into inedible forms. The primary aim of this study is to understand the phage conversion from organic to inorganic carbon during phage-host interactions. Time studies of phage-host interactions under controlled conditions reveal their impact on the total carbon content of the samples and their interconversion of organic and inorganic carbon compared to control samples. A total organic carbon (TOC) analysis showed an increase in inorganic carbon content by 15-25 percent in samples with bacteria and phage compared to samples with bacteria alone. Compared to control samples, the increase in inorganic carbon content was 60-70-fold in samples with bacteria and phage, and 50-55-fold for samples with bacteria alone. This study indicates the potential impact of phages in regulating the carbon cycle of aquatic systems.
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Affiliation(s)
- Swapnil Sanmukh
- Environmental Virology Cell, National Environmental Engineering Research Institute (NEERI), Nagpur, Maharashtra, 440020, India
| | - Krishna Khairnar
- Environmental Virology Cell, National Environmental Engineering Research Institute (NEERI), Nagpur, Maharashtra, 440020, India
| | - Waman Paunikar
- Environmental Virology Cell, National Environmental Engineering Research Institute (NEERI), Nagpur, Maharashtra, 440020, India
| | - Satish Lokhande
- Analytical Instrumentation Division (AID), CSIR-NEERI, Nehru Marg, Maharashtra, Nagpur-440020, India
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27
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Büntgen U, Peter M, Kauserud H, Egli S. Unraveling environmental drivers of a recent increase in Swiss fungi fruiting. Glob Chang Biol 2013; 19:2785-2794. [PMID: 23686649 DOI: 10.1111/gcb.12263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 05/09/2013] [Accepted: 05/09/2013] [Indexed: 06/02/2023]
Abstract
Disentangling biotic and abiotic drivers of wild mushroom fruiting is fraught with difficulties because mycelial growth is hidden belowground, symbiotic and saprotrophic supply strategies may interact, and myco-ecological observations are often either discontinuous or too short. Here, we compiled and analyzed 115 417 weekly fungal fruit body counts from permanent Swiss inventories between 1975 and 2006. Mushroom fruiting exhibited an average autumnal delay of 12 days after 1991 compared with before, the annual number of fruit bodies increased from 1801 to 5414 and the mean species richness doubled from 10 to 20. Intra- and interannual coherency of symbiotic and saprotrophic mushroom fruiting, together with little agreement between mycorrhizal yield and tree growth suggests direct climate controls on fruit body formation of both nutritional modes. Our results contradict a previously reported declining of mushroom harvests and propose rethinking the conceptual role of symbiotic pathways in fungi-host interaction. Moreover, this conceptual advancement may foster new cross-disciplinary research avenues, and stimulate questions about possible amplifications of the global carbon cycle, as enhanced fungal production in moist mid-latitude forests rises carbon cycling and thus increases greenhouse gas exchanges between terrestrial ecosystems and the atmosphere.
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Affiliation(s)
- Ulf Büntgen
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
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28
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Krausmann F, Erb KH, Gingrich S, Haberl H, Bondeau A, Gaube V, Lauk C, Plutzar C, Searchinger TD. Global human appropriation of net primary production doubled in the 20th century. Proc Natl Acad Sci U S A 2013; 110:10324-9. [PMID: 23733940 DOI: 10.1073/pnas.1211349110] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Global increases in population, consumption, and gross domestic product raise concerns about the sustainability of the current and future use of natural resources. The human appropriation of net primary production (HANPP) provides a useful measure of human intervention into the biosphere. The productive capacity of land is appropriated by harvesting or burning biomass and by converting natural ecosystems to managed lands with lower productivity. This work analyzes trends in HANPP from 1910 to 2005 and finds that although human population has grown fourfold and economic output 17-fold, global HANPP has only doubled. Despite this increase in efficiency, HANPP has still risen from 6.9 Gt of carbon per y in 1910 to 14.8 GtC/y in 2005, i.e., from 13% to 25% of the net primary production of potential vegetation. Biomass harvested per capita and year has slightly declined despite growth in consumption because of a decline in reliance on bioenergy and higher conversion efficiencies of primary biomass to products. The rise in efficiency is overwhelmingly due to increased crop yields, albeit frequently associated with substantial ecological costs, such as fossil energy inputs, soil degradation, and biodiversity loss. If humans can maintain the past trend lines in efficiency gains, we estimate that HANPP might only grow to 27-29% by 2050, but providing large amounts of bioenergy could increase global HANPP to 44%. This result calls for caution in refocusing the energy economy on land-based resources and for strategies that foster the continuation of increases in land-use efficiency without excessively increasing ecological costs of intensification.
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Norby RJ, Warren JM, Iversen CM, Medlyn BE, McMurtrie RE. CO2 enhancement of forest productivity constrained by limited nitrogen availability. Proc Natl Acad Sci U S A 2010; 107:19368-73. [PMID: 20974944 PMCID: PMC2984154 DOI: 10.1073/pnas.1006463107] [Citation(s) in RCA: 343] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stimulation of terrestrial plant production by rising CO(2) concentration is projected to reduce the airborne fraction of anthropogenic CO(2) emissions. Coupled climate-carbon cycle models are sensitive to this negative feedback on atmospheric CO(2), but model projections are uncertain because of the expectation that feedbacks through the nitrogen (N) cycle will reduce this so-called CO(2) fertilization effect. We assessed whether N limitation caused a reduced stimulation of net primary productivity (NPP) by elevated atmospheric CO(2) concentration over 11 y in a free-air CO(2) enrichment (FACE) experiment in a deciduous Liquidambar styraciflua (sweetgum) forest stand in Tennessee. During the first 6 y of the experiment, NPP was significantly enhanced in forest plots exposed to 550 ppm CO(2) compared with NPP in plots in current ambient CO(2), and this was a consistent and sustained response. However, the enhancement of NPP under elevated CO(2) declined from 24% in 2001-2003 to 9% in 2008. Global analyses that assume a sustained CO(2) fertilization effect are no longer supported by this FACE experiment. N budget analysis supports the premise that N availability was limiting to tree growth and declining over time--an expected consequence of stand development, which was exacerbated by elevated CO(2). Leaf- and stand-level observations provide mechanistic evidence that declining N availability constrained the tree response to elevated CO(2); these observations are consistent with stand-level model projections. This FACE experiment provides strong rationale and process understanding for incorporating N limitation and N feedback effects in ecosystem and global models used in climate change assessments.
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Affiliation(s)
- Richard J Norby
- Environmental Sciences Division , Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
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30
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Dolman AJ, van der Werf GR, van der Molen MK, Ganssen G, Erisman JW, Strengers B. A carbon cycle science update since IPCC AR-4. Ambio 2010; 39:402-12. [PMID: 21053724 PMCID: PMC3357713 DOI: 10.1007/s13280-010-0083-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 05/26/2010] [Accepted: 06/26/2010] [Indexed: 05/22/2023]
Abstract
We review important advances in our understanding of the global carbon cycle since the publication of the IPCC AR4. We conclude that: the anthropogenic emissions of CO2 due to fossil fuel burning have increased up through 2008 at a rate near to the high end of the IPCC emission scenarios; there are contradictory analyses whether an increase in atmospheric fraction, that might indicate a declining sink strength of ocean and/or land, exists; methane emissions are increasing, possibly through enhanced natural emission from northern wetland, methane emissions from dry plants are negligible; old-growth forest take up more carbon than expected from ecological equilibrium reasoning; tropical forest also take up more carbon than previously thought, however, for the global budget to balance, this would imply a smaller uptake in the northern forest; the exchange fluxes between the atmosphere and ocean are increasingly better understood and bottom up and observation-based top down estimates are getting closer to each other; the North Atlantic and Southern ocean take up less CO2, but it is unclear whether this is part of the 'natural' decadal scale variability; large-scale fires and droughts, for instance in Amazonia, but also at Northern latitudes, have lead to significant decreases in carbon uptake on annual timescales; the extra uptake of CO2 stimulated by increased N-deposition is, from a greenhouse gas forcing perspective, counterbalanced by the related additional N2O emissions; the amount of carbon stored in permafrost areas appears much (two times) larger than previously thought; preservation of existing marine ecosystems could require a CO2 stabilization as low as 450 ppm; Dynamic Vegetation Models show a wide divergence for future carbon trajectories, uncertainty in the process description, lack of understanding of the CO2 fertilization effect and nitrogen-carbon interaction are major uncertainties.
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Affiliation(s)
- A J Dolman
- Department of Earth Sciences, VU University Amsterdam, The Netherlands.
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