Biogeochemistry

  • Article
    | Open Access

    Here the authors show that 2-aminoethylphosphonate (2AEP) mineralisation is widespread in the global ocean, operating independently of exogenous inorganic phosphate concentration. They propose 2AEP may be a major route for the regeneration of phosphate required to support marine primary production.

    • Andrew R. J. Murphy
    • , David J. Scanlan
    •  & Ian D. E. A. Lidbury
  • Article
    | Open Access

    Plant and soil C:N:P ratios are critical to ecosystem functioning, but it remains uncertain how plant diversity affects terrestrial C:N:P. In this meta-analysis of 169 studies, the authors find that plant mixtures can balance plant and soil C:N:P ratios according to background soil C:N:P.

    • Xinli Chen
    •  & Han Y. H. Chen
  • Article
    | Open Access

    Relationships between biodiversity and phosphorus cycling and the underlying processes are complex. Here the authors analyse a biodiversity manipulation experiment and an agricultural management gradient to show how plant and mycorrhizal fungal diversity promote phosphorus exploitation.

    • Yvonne Oelmann
    • , Markus Lange
    •  & Wolfgang Wilcke
  • Article
    | Open Access

    To explore the importance of local vs. global sulfur-cycle controls on variations in pyrite sulfur isotopes, the authors couple carbon-nitrogen-sulfur concentrations and stable isotopes of sediments from the Peruvian oxygen minimum zone, identifying a major role for the local organic carbon loading.

    • Virgil Pasquier
    • , David A. Fike
    •  & Itay Halevy
  • Article
    | Open Access

    The deep North Pacific is the end of the road for global ocean circulation, but the circulation patterns and ventilation are poorly understood. Here the authors show that diffusive transports both along and across density layers play a leading role in returning 1,400 year old water to the surface.

    • Mark Holzer
    • , Tim DeVries
    •  & Casimir de Lavergne
  • Article
    | Open Access

    Advances in omics approaches could enable quantitative predictions of microbial functional composition. Here the authors re-analyze 885 metagenome-assembled genomes from Tara Oceans, and use a network approach to quantify protein functional clusters and explore their biogeography.

    • Emile Faure
    • , Sakina-Dorothée Ayata
    •  & Lucie Bittner
  • Article
    | Open Access

    Nitrogen fixation by diazotrophs is critical for marine primary production. Using Tara Oceans datasets, this study combines a quantitative image analysis pipeline with metagenomic mining to provide an improved global overview of diazotroph abundance, diversity and distribution.

    • Juan José Pierella Karlusich
    • , Eric Pelletier
    •  & Rachel A. Foster
  • Article
    | Open Access

    The fate of soil carbon is controlled by plant inputs, microbial activity, and the soil matrix. Here the authors extend the notion of plant-derived particulate organic matter, from an easily available and labile carbon substrate, to a functional component at which persistence of soil carbon is determined.

    • Kristina Witzgall
    • , Alix Vidal
    •  & Carsten W. Mueller
  • Article
    | Open Access

    Warmer and drier conditions are increasing the frequency of forest fires, which in turn produce pyrogenic carbon. Here the authors show that accumulation of pyrogenic carbon can suppress post-fire methane production in northern peatlands and can effectively buffer fire-derived greenhouse gas emissions.

    • Tianran Sun
    • , Juan J. L. Guzman
    •  & Largus T. Angenent
  • Article
    | Open Access

    N2 fixation by heterotrophic bacteria has recently been found to take place on sinking marine particles, but an understanding of its regulation and importance is lacking. Here the authors develop a trait-based model for this N2 fixation, finding that this once overlooked process could have global importance.

    • Subhendu Chakraborty
    • , Ken H. Andersen
    •  & Lasse Riemann
  • Article
    | Open Access

    Microbes that colonise ice sheet surfaces are important to the carbon cycle, but their biomass and transport remains unquantified. Here, the authors reveal substantial microbial carbon fluxes across Greenland’s ice surface, in quantities that may sustain subglacial heterotrophs and fuel methanogenesis.

    • T. D. L. Irvine-Fynn
    • , A. Edwards
    •  & A. Hubbard
  • Article
    | Open Access

    “Earth degassing is a critical carbon source, but its contribution to Cenozoic atmospheric CO2 variations is not well known. Here, the authors analyse CO2 fluxes on the Tibetan Plateau and suggest that the India-Asia collision was the primary driver of changes in atmospheric CO2 over the past 65 Ma.”

    • Zhengfu Guo
    • , Marjorie Wilson
    •  & Jiaqi Liu
  • Article
    | Open Access

    Conserving mangrove biodiversity has numerous co-benefits, including climate change-mitigation. Here the authors demonstrate that blue carbon storage in mangroves can be best sustained by combining site-specific dominant species with other species with contrasting functional traits.

    • Md Mizanur Rahman
    • , Martin Zimmer
    •  & Ming Xu
  • Article
    | Open Access

    Some bacteriophage encode auxiliary metabolic genes (AMGs) that impact host metabolism and biogeochemical cycling during infection. Here the authors identify hundreds of AMGs in environmental phage encoding sulfur oxidation genes and use their global distribution to infer phage-mediated biogeochemical impacts.

    • Kristopher Kieft
    • , Zhichao Zhou
    •  & Karthik Anantharaman
  • Article
    | Open Access

    Primary productivity in the oligotrophic ocean sustains Earth’s ecosystems, but nutrient concentrations are vanishingly low. Here the authors measure nanomolar macronutrient concentrations in the North Pacific and find that net community production is sustained through high rates of phosphorus recycling.

    • Fuminori Hashihama
    • , Ichiro Yasuda
    •  & Masao Ishii
  • Article
    | Open Access

    The fate of soil carbon depends on microbial processes, but whether different microbial taxa have individualistic effects on carbon fluxes is unknown. Here the authors use 16 S amplicon sequencing and stable isotopes to show how taxonomic differences influence bacterial respiration and carbon cycling across four ecosystems.

    • Bram W. Stone
    • , Junhui Li
    •  & Bruce A. Hungate
  • Article
    | Open Access

    The middle of the Gulf of Mexico is stratified and highly oligotrophic, yet there are anomalously high fluxes of sinking particulate matter from the euphotic zone. Here the authors show that lateral advection of organic matter supports nitrogen export in the Gulf of Mexico’s open ocean.

    • Thomas B. Kelly
    • , Angela N. Knapp
    •  & Michael R. Stukel
  • Article
    | Open Access

    Up to 40% of the ocean’s fixed nitrogen is lost in oxygen minimum zones (OMZs) by anammox, but despite the importance of this process, nitrogen loss patterns in OMZs are difficult to predict. Here the authors show that ammonium release from small particles is a major control of anammox in the Peruvian OMZ.

    • Clarissa Karthäuser
    • , Soeren Ahmerkamp
    •  & Marcel M. M. Kuypers
  • Article
    | Open Access

    Earth-system sensitivity (ESS) describes the long-term temperature response for a given change in atmospheric CO2 and, as such, is a crucial parameter to assess future climate change. Here, the authors use a Bayesian model with data from the last 420 Myrs to reduce uncertainties and estimate ESS to be around 3.4 °C.

    • Tony E. Wong
    • , Ying Cui
    •  & Klaus Keller
  • Article
    | Open Access

    Mercury is a neurotoxin and pollutant with enhanced emissions from anthropogenic activities. Here, the authors develop a global emissions, transport, and human risk model and find substantial future losses in revenue and public health if emission reductions proposed by the Minamata Convention are delayed.

    • Yanxu Zhang
    • , Zhengcheng Song
    •  & Ping Li
  • Article
    | Open Access

    The macroalgae Sargassum has grown for centuries in the oligotrophic North Atlantic supported by natural nutrient sources and cycling. Here the authors show that changes in tissue nutrient contents since the 1980s reflect global anthropogenic nitrogen enrichment, causing blooms in the wider Atlantic basin.

    • B. E. Lapointe
    • , R. A. Brewton
    •  & P. L. Morton
  • Article
    | Open Access

    A large fraction of ice sheet discharge enters the ocean subsurface from underneath large floating ice-tongues. Here the authors show that associated nutrient export may be governed by shelf circulation and, especially for Fe, particle-dissolved phase exchanges, which is largely independent from freshwater Fe content.

    • Stephan Krisch
    • , Mark James Hopwood
    •  & Eric Pieter Achterberg
  • Article
    | Open Access

    Expanded phosphorus availability possibly triggered a marine bioproduction boom after 2.3 billion years ago, but its delivery mechanisms remain unclear. Here we propose a kaolinite shuttle which efficiently adsorbs phosphorus in continental weathering settings and releases it under marine conditions.

    • Weiduo Hao
    • , Kaarel Mänd
    •  & Kurt O. Konhauser
  • Article
    | Open Access

    How to curb climate change is uncertain, in part because determination of allowable emissions depends on models with low accuracy. Here the authors re-analyze climate-carbon feedbacks and find that CO2 emissions could be 9 ± 7% higher and still meet Paris Agreement goals.

    • Xuanze Zhang
    • , Ying-Ping Wang
    •  & Yongqiang Zhang
  • Article
    | Open Access

    Marine snow is a major route through which photosynthetically fixed carbon is transported to the deep ocean, but the factors affecting flux are largely unknown. Here the authors use high frequency imaging of marine snow particles collected during phytoplankton blooms to categorize and quantify transport.

    • Emilia Trudnowska
    • , Léo Lacour
    •  & Lars Stemmann
  • Article
    | Open Access

    It is thought that polyphenols inhibit organic matter decomposition in soils devoid of oxygen. Here the authors use metabolomics and genome-resolved metaproteomics to provide experimental evidence of polyphenol biodegradation and maintained soil microbial community metabolism despite anoxia.

    • Bridget B. McGivern
    • , Malak M. Tfaily
    •  & Kelly C. Wrighton
  • Article
    | Open Access

    Understanding the past is necessary to comprehend Earth’s response to present climate change, but past climate reconstruction is hampered by a lack of temperature proxies. Here the authors develop the HDI26, a proxy using cyanobacterial glycolipids to reconstruct water temperatures of lakes worldwide.

    • Thorsten Bauersachs
    • , James M. Russell
    •  & Lorenz Schwark
  • Article
    | Open Access

    Microplastic pollution is a major threat to marine food webs, but the wider ranging impacts on global ocean biogeochemistry are poorly understood. Here the authors use an Earth system model to determine that zooplankton grazing on microplastics could exacerbate trends in ocean oxygen loss.

    • K. Kvale
    • , A. E. F. Prowe
    •  & A. Oschlies
  • Article
    | Open Access

    Ocean warming and changing circulation as a result of climate change are driving down oxygen levels and threatening ecosystems. Here the author shows that though immediate cessation of anthropogenic CO2 emissions would halt upper ocean oxygen loss, it would continue in the deep ocean for 100 s of years.

    • Andreas Oschlies
  • Article
    | Open Access

    Wetland methane emissions contribute to global warming, and are oversimplified in climate models. Here the authors use eddy covariance measurements from 48 global sites to demonstrate seasonal hysteresis in methane-temperature relationships and suggest the importance of microbial processes.

    • Kuang-Yu Chang
    • , William J. Riley
    •  & Donatella Zona
  • Article
    | Open Access

    The conditions that shaped Earth’s evolution during the Archaean and Proterozoic Eons remain unknown. Using Lake Towuti in Indonesia as an analog of early oceans the authors find that microbial methanogenesis exerts a strong influence with important implications for the composition of Earth’s early atmosphere.

    • André Friese
    • , Kohen Bauer
    •  & Jens Kallmeyer
  • Article
    | Open Access

    The photosynthesis performed by trees makes them an important sink for atmospheric carbon dioxide, but trees are also sources of the potent greenhouse gas methane. Here the authors find that tree bark in some common lowland species is colonized by methane oxidizing bacteria that can reduce tree methane emissions by ~ 36%.

    • Luke C. Jeffrey
    • , Damien T. Maher
    •  & Scott G. Johnston
  • Article
    | Open Access

    The Permian–Triassic mass extinction was accompanied by a massive release of carbon into the ocean-atmosphere system, but the magnitude of change is not well known. Here, the authors present a new record of C3 plants from southwestern China which shows that atmospheric pCO2 increased by a factor of six during this event.

    • Yuyang Wu
    • , Daoliang Chu
    •  & Ying Cui
  • Article
    | Open Access

    Palaeodata resolution and dating limit the study of the sequence of changes across Earth during past abrupt warmings. Here, the authors show tight decadal-scale coupling between Greenland climate, North Atlantic sea ice and atmospheric circulation during these past events using two highly resolved ice-core records.

    • E. Capron
    • , S. O. Rasmussen
    •  & J. W. C. White
  • Article
    | Open Access

    There is much uncertainty on the response of soil microbial communities to warming, particularly in the subsoil. Here, the authors investigate microbial community and metabolism response to 4.5 years of whole-profile soil warming, finding depth-dependent effects and elevated subsoil microbial respiration.

    • Nicholas C. Dove
    • , Margaret S. Torn
    •  & Neslihan Taş
  • Article
    | Open Access

    Cyanobacterial photosynthesis is thought to have oxygenated Earth’s atmosphere during the Great Oxidation Event, but these organisms had to overcome the toxic effects of iron. Here the authors simulate Archaean conditions in Cyanobacterial cultures and find that gas exchange and rust formation alleviated iron toxicity.

    • A. J. Herrmann
    • , J. Sorwat
    •  & M. M. Gehringer
  • Article
    | Open Access

    Radioactive 137Cs is a fission product remaining in the environment from mid-20th century nuclear testing. Here the authors show that vegetation thousands of kilometers from testing sites continues to cycle 137Cs, and consequently, bees magnify this contaminant in honey in regions with low soil potassium.

    • J. M. Kaste
    • , P. Volante
    •  & A. J. Elmore
  • Article
    | Open Access

    Inland waters emit greenhouse gases, but robust estimations are hampered by a dearth of spatio-temporally resolved measurements. Here the authors present annual fluxes of CO2 from Chinese inland waters over the past several decades, showing that emission fluxes have significantly declined since the 80s.

    • Lishan Ran
    • , David E. Butman
    •  & Shaoda Liu
  • Article
    | Open Access

    Determining the origins of life on Earth is confounded by the fact that the sources of nutrients necessary to create early life forms remain mysterious. Here the authors show that lightning strikes could have supplied a major source of essential phosphorus on early Earth.

    • Benjamin L. Hess
    • , Sandra Piazolo
    •  & Jason Harvey
  • Article
    | Open Access

    Anoxic marine zones are expanding and intensifying with climate change. Here the authors show that microbial dark carbon fixation influences the carbonate system and the stable isotope composition in waters off Chile, contributing up to 35% of the organic carbon reaching the mesopelagic region.

    • Cristian A. Vargas
    • , Sebastian I. Cantarero
    •  & Joe Salisbury
  • Article
    | Open Access

    The impacts of a melting Arctic on the biogeochemistry of marine ecosystems are unknown. Here, the authors investigate glacial input of iron to Svalbard fjords finding that reworking of glacial iron in fjord sediment is important to make iron bioavailable, but could be susceptible to glacial retreat.

    • Katja Laufer-Meiser
    • , Alexander B. Michaud
    •  & Bo Barker Jørgensen
  • Article
    | Open Access

    The extent to which chemical products of water radiolysis could sustain subseafloor microbial life is unknown. Here the authors show that sediment catalyzes radiolytic production of H2 and oxidants, providing the primary energy source for life in ancient marine sediment.

    • Justine F. Sauvage
    • , Ashton Flinders
    •  & Steven D’Hondt