Biogeochemistry

  • Article
    | Open Access

    Coastal systems have enormous carbon-sequestering potential, but any positive climate effects can be countered by methane emissions. Here the authors use sea level rise manipulation mesocosms in tidal wetlands to show that shifts in plant community composition have the greatest effect on methane emissions.

    • Peter Mueller
    • , Thomas J. Mozdzer
    •  & J. Patrick Megonigal
  • Article
    | Open Access

    The Si cycle is important to ocean productivity and nutrient cycling, however there are uncertainties in global budgets. Here the authors use a multi-isotope approach on seafloor sediments and pore fluids, finding that an unappreciated source of Si to the ocean is the degradation of seafloor serpentinites.

    • Sonja Geilert
    • , Patricia Grasse
    •  & Catriona D. Menzies
  • Article
    | Open Access

    Carbon stored in the Arctic is threatened by climate change, but models do not capture the local-scale heterogeneity that influences carbon dynamics. Here the authors refine tundra models to account for heterogeneity, finding improved projections and decreased uncertainty in assessing the fate of carbon.

    • M. J. Lara
    • , A. D. McGuire
    •  & S. D. Wullschleger
  • Article
    | Open Access

    Mechanisms and consequences of the acclimation of soil respiration to warming are unclear. Here, the authors combine soil respiration, metagenomics, and functional gene results from a 7-year grassland warming experiment to a microbial-enzyme decomposition model, showing functional gene information to lower uncertainty and improve fit.

    • Xue Guo
    • , Qun Gao
    •  & Jizhong Zhou
  • Article
    | Open Access

    Soil age is thought to be an important driver of ecosystem development. Here, the authors perform a global survey of soil chronosequences and meta-analysis to show that, contrary to expectations, soil age is a relatively minor ecosystem driver at the biome scale once other drivers such as parent material, climate, and vegetation type are accounted for.

    • Manuel Delgado-Baquerizo
    • , Peter B. Reich
    •  & Noah Fierer
  • Article
    | Open Access

    Permafrost locks away the largest reservoir of mercury on the planet, but climate warming threatens to thaw these systems. Here the authors use models to show that unconstrained fossil fuel burning will dramatically increase the amount of mercury released into future ecosystems.

    • Kevin Schaefer
    • , Yasin Elshorbany
    •  & Elsie M. Sunderland
  • Article
    | Open Access

    Dimethylsulfoniopropionate (DMSP) is an osmolyte produced by marine microbes that plays an important role in nutrient cycling and atmospheric chemistry. Here the authors go to the Mariana Trench—the deepest point in the ocean—and find bacteria are key DMSP producers, and that DMSP has a role in protection against high pressure.

    • Yanfen Zheng
    • , Jinyan Wang
    •  & Xiao-Hua Zhang
  • Article
    | Open Access

    Africa houses approximately one third of the global cattle, sheep and goat population. Here the authors show that manure accumulation in livestock enclosures can emit significant quantities of the greenhouse gas N2O for decades after abandonment, totaling 5% of continental anthropogenic N2O emissions.

    • Klaus Butterbach-Bahl
    • , Gretchen Gettel
    •  & Lutz Merbold
  • Review Article
    | Open Access

    Accounting guidelines exist for carbon flows in terrestrial and coastal ecosystems, but not shelf sea sediments. In this Review, the authors explore whether effective management of carbon stocks accumulating in shelf seas could contribute to a nation’s greenhouse gas emissions reduction targets.

    • Tiziana Luisetti
    • , Silvia Ferrini
    •  & Emmanouil Tyllianakis
  • Article
    | Open Access

    Phosphorus is an essential nutrient critical for agriculture, but because it is non-renewable its future availability is threatened. Here the authors show that across the globe most nations have net losses of phosphorus, with soil erosion as the major route of loss in Europe, Africa and South America.

    • Christine Alewell
    • , Bruno Ringeval
    •  & Pasquale Borrelli
  • Article
    | Open Access

    The universality of the trade-off between early growth and lifespan in trees and its implications are disputed. Analysing a global tree ring dataset and performing data-driven simulations, the authors demonstrate the pervasiveness of the trade-off and challenge current earth system models that predict a continuation of the carbon sink into mature forests under warming and increasing CO2.

    • R. J. W. Brienen
    • , L. Caldwell
    •  & E. Gloor
  • Article
    | Open Access

    Ocean uptake of carbon dioxide impacts the climate, but flux estimates from surface measurements have not been corrected for temperature differences between surface and water sampling depth. Making that correction, the authors find previous estimates for ocean uptake have been substantially underestimated.

    • Andrew J. Watson
    • , Ute Schuster
    •  & Lonneke Goddijn-Murphy
  • Article
    | Open Access

    Predicting the fate of carbon in peatlands relies on assumptions of behaviour in response to temperature. Here, the authors show that the temperature dependency of respiratory carbon losses shift strongly over day-night cycles, an overlooked facet causing bias in peatland carbon cycle simulations.

    • Järvi Järveoja
    • , Mats B. Nilsson
    •  & Matthias Peichl
  • Article
    | Open Access

    Mangroves and the carbon they store are threatened by deforestation, but the efficacy of policies to protect them is unknown. Here the authors assess changes in mangrove carbon stocks between 1996 and 2016 and show less loss than previous methods estimated, indicating conservation has had a positive effect.

    • Daniel R. Richards
    • , Benjamin S. Thompson
    •  & Lahiru Wijedasa
  • Article
    | Open Access

    Soil microbial communities remain active throughout much of the Arctic winter, and Arctic winters are warming dramatically. Here, the authors show that persistently warm winter soils can lead to labile carbon starvation and reduced microbial respiration, despite the high carbon content of most Arctic soils.

    • Patrick F. Sullivan
    • , Madeline C. Stokes
    •  & Michael N. Weintraub
  • Article
    | Open Access

    Some palaeotemperature proxies suffer from inaccuracies related to kinetic fractionations occurring during carbonate mineral growth. Here, the authors show that dual clumped isotope thermometry can identify the origin of these kinetic biases and allows for the reconstruction of accurate environmental temperatures.

    • David Bajnai
    • , Weifu Guo
    •  & Jens Fiebig
  • Article
    | Open Access

    Ocean cold seeps are poorly understood relative to related systems like hydrothermal vents. Here the authors use high pressure bioreactors and microbial communities from a cold seep mud volcano and find a previously missing step of methane conversion to acetate that likely fuels heterotrophic communities.

    • Shanshan Yang
    • , Yongxin Lv
    •  & Yu Zhang
  • Article
    | Open Access

    Geological sources of H2 and abiotic CH4 have had a critical role in the evolution of life and sustainability of the deep subsurface biosphere, yet the origins of these sources remain largely unconstrained. Here the authors show that deep serpentinization (40–80 km) during subduction generates significant amounts of H2 and abiotic CH4, potentially providing energy to the overlying subsurface biosphere.

    • A. Vitale Brovarone
    • , D. A. Sverjensky
    •  & I. Daniel
  • Article
    | Open Access

    Soil organism biodiversity contributes to ecosystem function, but biodiversity and function have not been equivalently studied across the globe. Here the authors identify locations, environment types, and taxonomic groups for which there is currently a lack of biodiversity and ecosystem function data in the existing literature.

    • Carlos A. Guerra
    • , Anna Heintz-Buschart
    •  & Nico Eisenhauer
  • Article
    | Open Access

    How the tropical mixed layer of the ocean reacts to near-inertial waves has rarely been observed directly. Here, the authors present new data that shows strongly elevated vertical diffusive heat flux in the presence of near-inertial waves, causing a cooling of the mixed layer that is particularly strong in summer.

    • Rebecca Hummels
    • , Marcus Dengler
    •  & Peter Brandt
  • Article
    | Open Access

    Cement plays a dual role in the carbon cycle like a sponge. Here, the authors employ a dynamic model to quantify such sponge effect and concluded that deep decarbonization of the global cement cycle will require radical technology advancements and widespread deployment of material efficiency measures.

    • Zhi Cao
    • , Rupert J. Myers
    •  & Gang Liu
  • Article
    | Open Access

    Ocean warming could enable the release of methane related to hydrate dissociation from the ocean floor, a process thought to have triggered abrupt climate changes in Earth history. Here the authors detect this process in action, observing a massive release of methane from a site in the South Atlantic Ocean.

    • Marcelo Ketzer
    • , Daniel Praeg
    •  & José A. Cupertino
  • Article
    | Open Access

    Ocean oxygen minimum zones (OMZs) are known to emit the powerful greenhouse gas N2O, but global emission dynamics are not constrained. Here the authors use air trajectory analyses and find that air masses pick up N2O as they pass over OMZs, and that overall concentrations are elevated during La Niña events.

    • Andrew R. Babbin
    • , Elisabeth L. Boles
    •  & Ray F. Weiss
  • Article
    | Open Access

    Microbial carbon use efficiency has an important role in soil C cycling. Here the authors test the interactive effects of temperature and moisture and manipulate microbial community composition in soil microcosms, showing a positive relationship between microbial diversity and CUE that is contingent on abiotic conditions.

    • Luiz A. Domeignoz-Horta
    • , Grace Pold
    •  & Kristen M. DeAngelis
  • Article
    | Open Access

    Microbial ammonia oxidation is important in marine nutrient cycling and greenhouse gas dynamics, but the responses to ocean warming are unclear. Here coast to open ocean incubations show that projected year 2100 temperatures might be too hot for these microbes in oligotrophic regions to handle, but may facilitate oxidation rates in coastal waters.

    • Zhen-Zhen Zheng
    • , Li-Wei Zheng
    •  & Shuh-Ji Kao
  • Article
    | Open Access

    Monomethylmercury is a toxin that humans can be exposed to after consumption of seafood in which it has bioaccumulated. Here the authors show that amphipods in the deepest point of the global ocean contain monomethylmercury with surface origins, suggesting rapid sinking of this toxin on particles.

    • Ruoyu Sun
    • , Jingjing Yuan
    •  & Congqiang Liu
  • Article
    | Open Access

    Massive stores of carbon and nutrients in permafrost could be released by global warming. Here the authors show that though warming across the Tibetan alpine permafrost region accelerates nitrogen liberation, contrary to expectations the elevated nutrients do not alleviate plant nitrogen limitation.

    • Dan Kou
    • , Guibiao Yang
    •  & Yuanhe Yang
  • Article
    | Open Access

    Terrestrial carbon uptake as high inter-annual variability which can be used to help understand future responses to climate change. Here the authors’ modeling reveals a large portion of this variability is driven by human land use changes and management, and not captured by other models.

    • Chao Yue
    • , Philippe Ciais
    •  & Alexander A. Nassikas
  • Article
    | Open Access

    Satellites can observe marine phytoplankton, but observations are sparse in seasonally dark, cloudy environments like the Southern Ocean. These authors use Argo floats to track the fate of phytoplankton blooms off Antarctica and determine 10% of biomass is exported, while 90% is prey to grazing.

    • Sébastien Moreau
    • , Philip W. Boyd
    •  & Peter G. Strutton
  • Article
    | Open Access

    The environmental changes at the Permian–Triassic boundary are thought to have been caused primarily by volcanic eruptions. Here the authors develop a model to show that the loss of ecosystems on land and consequent massive terrestrial biomass oxidation triggered large biogeochemical changes in the oceans at the time of the marine mass extinction.

    • Jacopo Dal Corso
    • , Benjamin J. W. Mills
    •  & Paul B. Wignall
  • Article
    | Open Access

    Black carbon is a recalcitrant and unique form of organic carbon formed from incomplete combustion. Here the authors use global sampling to reduce uncertainty in the flux of terrestrial black carbon to the oceans, predicting that 34% of black carbon produced by fires has an oceanic fate.

    • Matthew W. Jones
    • , Alysha I. Coppola
    •  & Timothy A. Quine
  • Article
    | Open Access

    The early Earth’s atmosphere had very low oxygen levels for hundreds of millions of years, until the 2.4 Ga Great Oxidation Event, which remains poorly understood. Here, the authors show that reducing Archean volcanic gases could have prevented atmospheric O2 from accumulating, and therefore mantle oxidation was likely very important in setting the evolution of O2 and aerobic life.

    • Shintaro Kadoya
    • , David C. Catling
    •  & Ariel D. Anbar
  • Article
    | Open Access

    Biology can profoundly influence the planet’s climate, but over Earth’s long history these effects are poorly constrained. Here the authors show that on early Earth, the evolution of microbes producing and consuming methane likely controlled warming and glacial events, and thus Earth’s habitability

    • Boris Sauterey
    • , Benjamin Charnay
    •  & Régis Ferrière
  • Article
    | Open Access

    Anthropogenic CO2 is acidifying the ocean, but knowledge of the carbonate properties underlying these dynamics in coastal oceans is lacking. Here, the authors reveal spatial distribution patterns and variability in carbonate chemistry along North America’s coasts.

    • Wei-Jun Cai
    • , Yuan-Yuan Xu
    •  & Dwight K. Gledhill
  • Article
    | Open Access

    The ubiquitous oceanic bacteria harbour an external phosphate buffer for modulating phosphate (Pi) uptake. Here, using both oceanic SAR11, Prochlorococcus and Synechococcus strains as a model, the authors show that the Pi buffer accumulation in the periplasm is proton motive force-dependent and can be enhanced by light energy.

    • Nina A. Kamennaya
    • , Kalotina Geraki
    •  & Mikhail V. Zubkov
  • Article
    | Open Access

    Warming is expected to increase C sink capacity in high-latitude ecosystems, but plant-herbivore interactions could moderate or offset this effect. Here, Silfver and colleagues test individual and interactive effects of warming and insect herbivory in a field experiment in Subarctic forest, showing that even low intensity insect herbivory strongly reduces C sink potential.

    • Tarja Silfver
    • , Lauri Heiskanen
    •  & Juha Mikola
  • Article
    | Open Access

    Snow algae bloom along the coast of Antarctica and are likely to be biogeochemically important. Here, the authors produced the first map of such blooms, show that they are driven by warmer temperatures and proximity to birds and mammals, and are likely to increase given projected climate changes.

    • Andrew Gray
    • , Monika Krolikowski
    •  & Matthew P. Davey
  • Review Article
    | Open Access

    Coastal systems are hotspots of ecological, geochemical and economic activity, yet their dynamics are not accurately represented in global models. In this Review, Ward and colleagues assess the current state of coastal science and recommend approaches for including the coastal interface in predictive models.

    • Nicholas D. Ward
    • , J. Patrick Megonigal
    •  & Lisamarie Windham-Myers
  • Article
    | Open Access

    Plastic pollution has infiltrated every ecosystem, but few studies have quantified the biogeochemical or ecological effects of plastic. Here the authors show that microplastics in ocean sediment can significantly alter microbial community structure and nitrogen cycling.

    • Meredith E. Seeley
    • , Bongkeun Song
    •  & Robert C. Hale
  • Article
    | Open Access

    One-third of Earth’s carbon is sequestered in peatlands, and its stability in the face of climate change is unknown. Here the authors show that warming leads to the release of carbon as methane, but only the most prolonged warming leads to the breakdown and release of deep, old carbon.

    • A. M. Hopple
    • , R. M. Wilson
    •  & S. D. Bridgham
  • Article
    | Open Access

    Identification of stratospheric volcanic eruptions in the geological record and their link to mass extinction events during the past 540 million years remains challenging. Here, the authors report unexpected, large mass-independent sulphur isotopic compositions of pyrite in Late Ordovician sedimentary rocks, which they suggest originates from stratospheric volcanism linked to the first pulse of the Late Ordovician mass extinction.

    • Dongping Hu
    • , Menghan Li
    •  & Yanan Shen
  • Article
    | Open Access

    CH4 seepage mostly occurs in petroleum-bearing sedimentary basins, but the role of tectonics in degassing is mostly only known at a local scale. Here, the authors conduct a global scale analysis of seeps, faults, sedimentary basins, petroleum fields and heat flow, and find that geological CH4 seepage preferably develops in convergent basins, while gas seeps can occur along any brittle tectonic structure.

    • Giancarlo Ciotoli
    • , Monia Procesi
    •  & Guido Ventura
  • Article
    | Open Access

    Reactive iron minerals protect vast amounts of terrestrial carbon from decomposition and release as CO2. Here the authors show that reactive iron alone does not provide sufficient protection except under strict oxic conditions—instead, iron itself promotes carbon decomposition.

    • Chunmei Chen
    • , Steven J. Hall
    •  & Aaron Thompson
  • Article
    | Open Access

    Generally it is thought that confining clay layers provide protection to low-arsenic groundwaters against intrusion of shallower, high-arsenic groundwater bodies. Here, the authors show that impermeable clay layers can increase arsenic input to underlying groundwater systems due to reduction of iron oxides coupled to carbon oxidation.

    • Ivan Mihajlov
    • , M. Rajib H. Mozumder
    •  & Alexander van Geen
  • Article
    | Open Access

    Previous work suggests that marine oxygen levels and bioturbation are important factors that shape phosphorus burial and the size of the marine biosphere. Here the authors show that seawater calcium concentration is a key factor in controlling marine P burial, and thus the global oxygen cycle.

    • Mingyu Zhao
    • , Shuang Zhang
    •  & Noah Planavsky
  • Article
    | Open Access

    Threats to marine ecosystems are increasing due to ocean acidification, but trends are spatiotemporally difficult to monitor or predict. Here the authors use an Earth system model to accurately predict surface pH changes in the economically and ecologically important California Current System.

    • Riley X. Brady
    • , Nicole S. Lovenduski
    •  & Keith Lindsay