Articles | Volume 13, issue 15
https://doi.org/10.5194/bg-13-4379-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-13-4379-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
08 Aug 2016
Research article |
| 08 Aug 2016
Assessing approaches to determine the effect of ocean acidification on bacterial processes
Timothy J. Burrell
CORRESPONDING AUTHOR
National Institute of Water and Atmospheric Research,
Greta Point, Wellington, New Zealand
Victoria University of Wellington, School of Biological
Sciences, Wellington, New Zealand
now at: C-MORE, University of Hawaii at
Mānoa, Honolulu 96822, Hawaii, USA
Elizabeth W. Maas
National Institute of Water and Atmospheric Research,
Greta Point, Wellington, New Zealand
now at: Verification Services Department, Ministry for Primary Industry, P.O. Box 12034,
Ahuriri, Napier, New Zealand
Paul Teesdale-Spittle
Victoria University of Wellington, School of Biological
Sciences, Wellington, New Zealand
Cliff S. Law
National Institute of Water and Atmospheric Research,
Greta Point, Wellington, New Zealand
Department of Chemistry, University of Otago, Dunedin,
New Zealand
Related authors
Luke T. Cravigan, Marc D. Mallet, Petri Vaattovaara, Mike J. Harvey, Cliff S. Law, Robin L. Modini, Lynn M. Russell, Ed Stelcer, David D. Cohen, Greg Olsen, Karl Safi, Timothy J. Burrell, and Zoran Ristovski
Atmos. Chem. Phys., 20, 7955–7977, https://doi.org/10.5194/acp-20-7955-2020, https://doi.org/10.5194/acp-20-7955-2020, 2020
Short summary
Short summary
Aerosol–cloud interactions in remote marine environments are poorly represented in atmospheric modelling, particularly over the Southern Hemisphere. This work reports in situ chamber observations of sea spray aerosol composition and water uptake during the Surface Ocean Aerosol Production (SOAP) voyage. Observations were compared with currently applied models for sea spray organic enrichment. The sea spray hygroscopicity was persistently high, even at high organic fractions.
T. J. Burrell, E. W. Maas, P. Teesdale-Spittle, and C. S. Law
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-5841-2015, https://doi.org/10.5194/bgd-12-5841-2015, 2015
Manuscript not accepted for further review
Short summary
Short summary
pH has a significant effect on the artificial fluorophore for glucosidase and protease activity, while artificial aminopeptidase substrate alters the pH of seawater. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5h), while no significant response was detected for leucine aminopeptidase. Seawater acidified by bubbling CO2 gas resulted in elevated β-glucosidase activity and bacterial cell numbers, although seasonal effects were observed.
Karine Sellegri, Theresa Barthelmeß, Jonathan Trueblood, Antonia Cristi, Evelyn Freney, Clémence Rose, Neill Barr, Mike Harvey, Karl Safi, Stacy Deppeler, Karen Thompson, Wayne Dillon, Anja Engel, and Cliff Law
Atmos. Chem. Phys., 23, 12949–12964, https://doi.org/10.5194/acp-23-12949-2023, https://doi.org/10.5194/acp-23-12949-2023, 2023
Short summary
Short summary
The amount of sea spray emitted to the atmosphere depends on the ocean temperature, but this dependency is not well understood, especially when ocean biology is involved. In this study, we show that sea spray emissions are increased by up to a factor of 4 at low seawater temperatures compared to moderate temperatures, and we quantify the temperature dependence as a function of the ocean biogeochemistry.
Manon Rocco, Erin Dunne, Alexia Saint-Macary, Maija Peltola, Theresa Barthelmeß, Neill Barr, Karl Safi, Andrew Marriner, Stacy Deppeler, James Harnwell, Anja Engel, Aurélie Colomb, Alfonso Saiz-Lopez, Mike Harvey, Cliff S. Law, and Karine Sellegri
EGUsphere, https://doi.org/10.5194/egusphere-2023-516, https://doi.org/10.5194/egusphere-2023-516, 2023
Preprint archived
Short summary
Short summary
During the Sea2cloud campaign in the Southern Pacific Ocean, we measured air-sea emissions from phytopankton of two key atmospheric compounds: DMS and MeSH. These compounds are well-known to play a great role in atmospheric chemistry and climate. We see in this paper that these compounds are most emited by the nanophytoplankton population. We provide here parameters for climate models to predict future trends of the emissions of these compounds and their roles and impacts on the global warming.
Alexia D. Saint-Macary, Andrew Marriner, Theresa Barthelmeß, Stacy Deppeler, Karl Safi, Rafael Costa Santana, Mike Harvey, and Cliff S. Law
Ocean Sci., 19, 1–15, https://doi.org/10.5194/os-19-1-2023, https://doi.org/10.5194/os-19-1-2023, 2023
Short summary
Short summary
The uppermost oceanic layer was sampled to determine what can explain a potential dimethyl sulfide (DMS) enrichment in this environment. A novel sampling method was used, and the results showed that DMS was not as enriched as expected. Our results showed that the phytoplanktonic composition influenced the DMS concentration, confirming results from another study in this oceanic region. However, additional factors are required to observe a DMS enrichment in the uppermost oceanic layer.
Alexia D. Saint-Macary, Andrew Marriner, Stacy Deppeler, Karl A. Safi, and Cliff S. Law
Ocean Sci., 18, 1559–1571, https://doi.org/10.5194/os-18-1559-2022, https://doi.org/10.5194/os-18-1559-2022, 2022
Short summary
Short summary
To understand how dimethyl sulfide (DMS) enrichment is maintained in the sea surface microlayer (SML) while DMS is lost to the atmosphere, deck-board incubation was carried out to determine DMS sources and sinks. Our results showed that the phytoplankton composition played an essential role in DMS processes in the SML. However, all accumulated DMS processes were lower than the calculated air–sea DMS flux.
Jesse M. Vance, Kim Currie, John Zeldis, Peter W. Dillingham, and Cliff S. Law
Biogeosciences, 19, 241–269, https://doi.org/10.5194/bg-19-241-2022, https://doi.org/10.5194/bg-19-241-2022, 2022
Short summary
Short summary
Long-term monitoring is needed to detect changes in our environment. Time series of ocean carbon have aided our understanding of seasonal cycles and provided evidence for ocean acidification. Data gaps are inevitable, yet no standard method for filling gaps exists. We present a regression approach here and compare it to seven other common methods to understand the impact of different approaches when assessing seasonal to climatic variability in ocean carbon.
Stefanie Kremser, Mike Harvey, Peter Kuma, Sean Hartery, Alexia Saint-Macary, John McGregor, Alex Schuddeboom, Marc von Hobe, Sinikka T. Lennartz, Alex Geddes, Richard Querel, Adrian McDonald, Maija Peltola, Karine Sellegri, Israel Silber, Cliff S. Law, Connor J. Flynn, Andrew Marriner, Thomas C. J. Hill, Paul J. DeMott, Carson C. Hume, Graeme Plank, Geoffrey Graham, and Simon Parsons
Earth Syst. Sci. Data, 13, 3115–3153, https://doi.org/10.5194/essd-13-3115-2021, https://doi.org/10.5194/essd-13-3115-2021, 2021
Short summary
Short summary
Aerosol–cloud interactions over the Southern Ocean are poorly understood and remain a major source of uncertainty in climate models. This study presents ship-borne measurements, collected during a 6-week voyage into the Southern Ocean in 2018, that are an important supplement to satellite-based measurements. For example, these measurements include data on low-level clouds and aerosol composition in the marine boundary layer, which can be used in climate model evaluation efforts.
Luke T. Cravigan, Marc D. Mallet, Petri Vaattovaara, Mike J. Harvey, Cliff S. Law, Robin L. Modini, Lynn M. Russell, Ed Stelcer, David D. Cohen, Greg Olsen, Karl Safi, Timothy J. Burrell, and Zoran Ristovski
Atmos. Chem. Phys., 20, 7955–7977, https://doi.org/10.5194/acp-20-7955-2020, https://doi.org/10.5194/acp-20-7955-2020, 2020
Short summary
Short summary
Aerosol–cloud interactions in remote marine environments are poorly represented in atmospheric modelling, particularly over the Southern Hemisphere. This work reports in situ chamber observations of sea spray aerosol composition and water uptake during the Surface Ocean Aerosol Production (SOAP) voyage. Observations were compared with currently applied models for sea spray organic enrichment. The sea spray hygroscopicity was persistently high, even at high organic fractions.
Sinikka T. Lennartz, Christa A. Marandino, Marc von Hobe, Meinrat O. Andreae, Kazushi Aranami, Elliot Atlas, Max Berkelhammer, Heinz Bingemer, Dennis Booge, Gregory Cutter, Pau Cortes, Stefanie Kremser, Cliff S. Law, Andrew Marriner, Rafel Simó, Birgit Quack, Günther Uher, Huixiang Xie, and Xiaobin Xu
Earth Syst. Sci. Data, 12, 591–609, https://doi.org/10.5194/essd-12-591-2020, https://doi.org/10.5194/essd-12-591-2020, 2020
Short summary
Short summary
Sulfur-containing trace gases in the atmosphere influence atmospheric chemistry and the energy budget of the Earth by forming aerosols. The ocean is an important source of the most abundant sulfur gas in the atmosphere, carbonyl sulfide (OCS) and its most important precursor carbon disulfide (CS2). In order to assess global variability of the sea surface concentrations of both gases to calculate their oceanic emissions, we have compiled a database of existing shipborne measurements.
Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. de Bruyn, and Eric S. Saltzman
Atmos. Chem. Phys., 20, 3061–3078, https://doi.org/10.5194/acp-20-3061-2020, https://doi.org/10.5194/acp-20-3061-2020, 2020
Short summary
Short summary
Methanethiol (MeSH) is a reduced sulfur gas originating from phytoplankton, with a global ocean source of ~ 17 % of dimethyl sulfide (DMS). It has been little studied and is rarely observed over the ocean. In this work, MeSH was measured at much higher levels than previously observed (3–36 % of parallel DMS mixing ratios). MeSH could be a significant source of atmospheric sulfur over productive regions of the ocean, but its distribution, and its atmospheric impact, requires more investigation.
Samuel T. Wilson, Hermann W. Bange, Damian L. Arévalo-Martínez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John L. Bullister, Macarena Burgos, David W. Capelle, Michael Casso, Mercedes de la Paz, Laura Farías, Lindsay Fenwick, Sara Ferrón, Gerardo Garcia, Michael Glockzin, David M. Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara C. Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John W. Pohlman, Andrew P. Rees, Alyson E. Santoro, Philippe D. Tortell, Robert C. Upstill-Goddard, David P. Wisegarver, Gui-Ling Zhang, and Gregor Rehder
Biogeosciences, 15, 5891–5907, https://doi.org/10.5194/bg-15-5891-2018, https://doi.org/10.5194/bg-15-5891-2018, 2018
Short summary
Short summary
To determine the variability between independent measurements of dissolved methane and nitrous oxide, seawater samples were analyzed by multiple laboratories. The results revealed the influences of the different parts of the analytical process, from the initial sample collection to the calculation of the final concentrations. Recommendations are made to improve dissolved methane and nitrous oxide measurements to help preclude future analytical discrepancies between laboratories.
Murray J. Smith, Carolyn F. Walker, Thomas G. Bell, Mike J. Harvey, Eric S. Saltzman, and Cliff S. Law
Atmos. Chem. Phys., 18, 5861–5877, https://doi.org/10.5194/acp-18-5861-2018, https://doi.org/10.5194/acp-18-5861-2018, 2018
Short summary
Short summary
The transfer of gases across the air–sea interface has a significant influence on climate. During a research voyage in the South Pacific we measured the transfer rate of the biogenic gas dimethyl sulfide (DMS) from the ocean using two independent methods. The agreement between the techniques provides confidence in their use in compilations of global gas transfer. We also identified physical conditions under which the observations are not well predicted by a standard gas transfer model.
Yuanyuan Feng, Michael Y. Roleda, Evelyn Armstrong, Cliff S. Law, Philip W. Boyd, and Catriona L. Hurd
Biogeosciences, 15, 581–595, https://doi.org/10.5194/bg-15-581-2018, https://doi.org/10.5194/bg-15-581-2018, 2018
Short summary
Short summary
We conducted a series of incubation experiments to understand how the changes in five environmental drivers will affect the elemental composition of the calcifying phytoplankton species Emiliania huxleyi. These findings provide new diagnostic information to aid our understanding of how the physiology and the related marine biogeochemistry of the ecologically important species Emiliania huxleyi will respond to changes in different environmental drivers in the global climate change scenario.
Martine Lizotte, Maurice Levasseur, Cliff S. Law, Carolyn F. Walker, Karl A. Safi, Andrew Marriner, and Ronald P. Kiene
Ocean Sci., 13, 961–982, https://doi.org/10.5194/os-13-961-2017, https://doi.org/10.5194/os-13-961-2017, 2017
Short summary
Short summary
During a 4-week oceanographic cruise in 2012, we investigated the water masses bordering the subtropical front near New Zealand as sources of the biogenic gas dimethyl sulfide (DMS). DMS oxidation products may influence the atmospheric radiative budget of the Earth. Concentrations of DMS were high in the study region and DMS's precursor, dimethylsulfoniopropionate, showed a strong association with phytoplankton biomass in relation to the persistent dominance of dinoflagellates/coccolithophores.
Cliff S. Law, Murray J. Smith, Mike J. Harvey, Thomas G. Bell, Luke T. Cravigan, Fiona C. Elliott, Sarah J. Lawson, Martine Lizotte, Andrew Marriner, John McGregor, Zoran Ristovski, Karl A. Safi, Eric S. Saltzman, Petri Vaattovaara, and Carolyn F. Walker
Atmos. Chem. Phys., 17, 13645–13667, https://doi.org/10.5194/acp-17-13645-2017, https://doi.org/10.5194/acp-17-13645-2017, 2017
Short summary
Short summary
We carried out a multidisciplinary study to examine how aerosol production is influenced by the production and emission of trace gases and particles in the surface ocean. Phytoplankton blooms of different species composition in frontal waters southeast of New Zealand were a significant source of dimethylsulfide and other aerosol precursors. The relationships between surface ocean biogeochemistry and aerosol composition will inform the understanding of aerosol production over the remote ocean.
Carolyn F. Walker, Mike J. Harvey, Murray J. Smith, Thomas G. Bell, Eric S. Saltzman, Andrew S. Marriner, John A. McGregor, and Cliff S. Law
Ocean Sci., 12, 1033–1048, https://doi.org/10.5194/os-12-1033-2016, https://doi.org/10.5194/os-12-1033-2016, 2016
T. J. Burrell, E. W. Maas, P. Teesdale-Spittle, and C. S. Law
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-5841-2015, https://doi.org/10.5194/bgd-12-5841-2015, 2015
Manuscript not accepted for further review
Short summary
Short summary
pH has a significant effect on the artificial fluorophore for glucosidase and protease activity, while artificial aminopeptidase substrate alters the pH of seawater. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5h), while no significant response was detected for leucine aminopeptidase. Seawater acidified by bubbling CO2 gas resulted in elevated β-glucosidase activity and bacterial cell numbers, although seasonal effects were observed.
T. G. Bell, W. De Bruyn, C. A. Marandino, S. D. Miller, C. S. Law, M. J. Smith, and E. S. Saltzman
Atmos. Chem. Phys., 15, 1783–1794, https://doi.org/10.5194/acp-15-1783-2015, https://doi.org/10.5194/acp-15-1783-2015, 2015
Related subject area
Earth System Science/Response to Global Change: Climate Change
Carbon cycle feedbacks in an idealized simulation and a scenario simulation of negative emissions in CMIP6 Earth system models
Spatiotemporal heterogeneity in the increase in ocean acidity extremes in the northeastern Pacific
Anthropogenic climate change drives non-stationary phytoplankton internal variability
The response of wildfire regimes to Last Glacial Maximum carbon dioxide and climate
Simulated responses of soil carbon to climate change in CMIP6 Earth system models: the role of false priming
Alkalinity biases in CMIP6 Earth system models and implications for simulated CO2 drawdown via artificial alkalinity enhancement
Experiments of the efficacy of tree ring blue intensity as a climate proxy in central and western China
Burned area and carbon emissions across northwestern boreal North America from 2001–2019
Quantifying land carbon cycle feedbacks under negative CO2 emissions
The potential of an increased deciduous forest fraction to mitigate the effects of heat extremes in Europe
The effect of forest cover changes on the regional climate conditions in Europe during the period 1986–2015
Ideas and perspectives: Alleviation of functional limitations by soil organisms is key to climate feedbacks from arctic soils
A comparison of the climate and carbon cycle effects of carbon removal by afforestation and an equivalent reduction in fossil fuel emissions
Stability of alkalinity in ocean alkalinity enhancement (OAE) approaches – consequences for durability of CO2 storage
Ideas and perspectives: Land–ocean connectivity through groundwater
Bioclimatic change as a function of global warming from CMIP6 climate projections
Reconciling different approaches to quantifying land surface temperature impacts of afforestation using satellite observations
Drivers of intermodel uncertainty in land carbon sink projections
Reviews and syntheses: A framework to observe, understand and project ecosystem response to environmental change in the East Antarctic Southern Ocean
Acidification impacts and acclimation potential of Caribbean benthic foraminifera assemblages in naturally discharging low-pH water
Monitoring vegetation condition using microwave remote sensing: the standardized vegetation optical depth index (SVODI)
Evaluation of soil carbon simulation in CMIP6 Earth system models
Diazotrophy as a key driver of the response of marine net primary productivity to climate change
Impact of negative and positive CO2 emissions on global warming metrics using an ensemble of Earth system model simulations
Acidification, deoxygenation, and nutrient and biomass declines in a warming Mediterranean Sea
Ocean alkalinity enhancement – avoiding runaway CaCO3 precipitation during quick and hydrated lime dissolution
Assessment of the impacts of biological nitrogen fixation structural uncertainty in CMIP6 earth system models
Soil carbon loss in warmed subarctic grasslands is rapid and restricted to topsoil
The European forest carbon budget under future climate conditions and current management practices
The influence of mesoscale climate drivers on hypoxia in a fjord-like deep coastal inlet and its potential implications regarding climate change: examining a decade of water quality data
Contrasting responses of phytoplankton productivity between coastal and offshore surface waters in the Taiwan Strait and the South China Sea to short-term seawater acidification
Modeling interactions between tides, storm surges, and river discharges in the Kapuas River delta
The application of dendrometers to alpine dwarf shrubs – a case study to investigate stem growth responses to environmental conditions
Climate, land cover and topography: essential ingredients in predicting wetland permanence
Not all biodiversity rich spots are climate refugia
Evaluating the dendroclimatological potential of blue intensity on multiple conifer species from Tasmania and New Zealand
Anthropogenic CO2-mediated freshwater acidification limits survival, calcification, metabolism, and behaviour in stress-tolerant freshwater crustaceans
Quantifying the role of moss in terrestrial ecosystem carbon dynamics in northern high latitudes
On the influence of erect shrubs on the irradiance profile in snow
Tolerance of tropical marine microphytobenthos exposed to elevated irradiance and temperature
Persistent impacts of the 2018 drought on forest disturbance regimes in Europe
Reviews and syntheses: Arctic fire regimes and emissions in the 21st century
Slowdown of the greening trend in natural vegetation with further rise in atmospheric CO2
Effects of elevated CO2 and extreme climatic events on forage quality and in vitro rumen fermentation in permanent grassland
Cushion bog plant community responses to passive warming in southern Patagonia
Blue carbon stocks and exchanges along the California coast
Oceanic primary production decline halved in eddy-resolving simulations of global warming
Assessing climate change impacts on live fuel moisture and wildfire risk using a hydrodynamic vegetation model
Does drought advance the onset of autumn leaf senescence in temperate deciduous forest trees?
Ocean carbon cycle feedbacks in CMIP6 models: contributions from different basins
Ali Asaadi, Jörg Schwinger, Hanna Lee, Jerry Tjiputra, Vivek Arora, Roland Séférian, Spencer Liddicoat, Tomohiro Hajima, Yeray Santana-Falcón, and Chris D. Jones
Biogeosciences, 21, 411–435, https://doi.org/10.5194/bg-21-411-2024, https://doi.org/10.5194/bg-21-411-2024, 2024
Short summary
Short summary
Carbon cycle feedback metrics are employed to assess phases of positive and negative CO2 emissions. When emissions become negative, we find that the model disagreement in feedback metrics increases more strongly than expected from the assumption that the uncertainties accumulate linearly with time. The geographical patterns of such metrics over land highlight that differences in response between tropical/subtropical and temperate/boreal ecosystems are a major source of model disagreement.
Flora Desmet, Matthias Münnich, and Nicolas Gruber
Biogeosciences, 20, 5151–5175, https://doi.org/10.5194/bg-20-5151-2023, https://doi.org/10.5194/bg-20-5151-2023, 2023
Short summary
Short summary
Ocean acidity extremes in the upper 250 m depth of the northeastern Pacific rapidly increase with atmospheric CO2 rise, which is worrisome for marine organisms that rapidly experience pH levels outside their local environmental conditions. Presented research shows the spatiotemporal heterogeneity in this increase between regions and depths. In particular, the subsurface increase is substantially slowed down by the presence of mesoscale eddies, often not resolved in Earth system models.
Geneviève W. Elsworth, Nicole S. Lovenduski, Kristen M. Krumhardt, Thomas M. Marchitto, and Sarah Schlunegger
Biogeosciences, 20, 4477–4490, https://doi.org/10.5194/bg-20-4477-2023, https://doi.org/10.5194/bg-20-4477-2023, 2023
Short summary
Short summary
Anthropogenic climate change will influence marine phytoplankton over the coming century. Here, we quantify the influence of anthropogenic climate change on marine phytoplankton internal variability using an Earth system model ensemble and identify a decline in global phytoplankton biomass variance with warming. Our results suggest that climate mitigation efforts that account for marine phytoplankton changes should also consider changes in phytoplankton variance driven by anthropogenic warming.
Olivia Haas, Iain Colin Prentice, and Sandy P. Harrison
Biogeosciences, 20, 3981–3995, https://doi.org/10.5194/bg-20-3981-2023, https://doi.org/10.5194/bg-20-3981-2023, 2023
Short summary
Short summary
We quantify the impact of CO2 and climate on global patterns of burnt area, fire size, and intensity under Last Glacial Maximum (LGM) conditions using three climate scenarios. Climate change alone did not produce the observed LGM reduction in burnt area, but low CO2 did through reducing vegetation productivity. Fire intensity was sensitive to CO2 but strongly affected by changes in atmospheric dryness. Low CO2 caused smaller fires; climate had the opposite effect except in the driest scenario.
Rebecca M. Varney, Sarah E. Chadburn, Eleanor J. Burke, Simon Jones, Andy J. Wiltshire, and Peter M. Cox
Biogeosciences, 20, 3767–3790, https://doi.org/10.5194/bg-20-3767-2023, https://doi.org/10.5194/bg-20-3767-2023, 2023
Short summary
Short summary
This study evaluates soil carbon projections during the 21st century in CMIP6 Earth system models. In general, we find a reduced spread of changes in global soil carbon in CMIP6 compared to the previous CMIP5 generation. The reduced CMIP6 spread arises from an emergent relationship between soil carbon changes due to change in plant productivity and soil carbon changes due to changes in turnover time. We show that this relationship is consistent with false priming under transient climate change.
Claudia Hinrichs, Peter Köhler, Christoph Völker, and Judith Hauck
Biogeosciences, 20, 3717–3735, https://doi.org/10.5194/bg-20-3717-2023, https://doi.org/10.5194/bg-20-3717-2023, 2023
Short summary
Short summary
This study evaluated the alkalinity distribution in 14 climate models and found that most models underestimate alkalinity at the surface and overestimate it in the deeper ocean. It highlights the need for better understanding and quantification of processes driving alkalinity distribution and calcium carbonate dissolution and the importance of accounting for biases in model results when evaluating potential ocean alkalinity enhancement experiments.
Yonghong Zheng, Huanfeng Shen, Rory Abernethy, and Rob Wilson
Biogeosciences, 20, 3481–3490, https://doi.org/10.5194/bg-20-3481-2023, https://doi.org/10.5194/bg-20-3481-2023, 2023
Short summary
Short summary
Investigations in central and western China show that tree ring inverted latewood intensity expresses a strong positive relationship with growing-season temperatures, indicating exciting potential for regions south of 30° N that are traditionally not targeted for temperature reconstructions. Earlywood BI also shows good potential to reconstruct hydroclimate parameters in some humid areas and will enhance ring-width-based hydroclimate reconstructions in the future.
Stefano Potter, Sol Cooperdock, Sander Veraverbeke, Xanthe Walker, Michelle C. Mack, Scott J. Goetz, Jennifer Baltzer, Laura Bourgeau-Chavez, Arden Burrell, Catherine Dieleman, Nancy French, Stijn Hantson, Elizabeth E. Hoy, Liza Jenkins, Jill F. Johnstone, Evan S. Kane, Susan M. Natali, James T. Randerson, Merritt R. Turetsky, Ellen Whitman, Elizabeth Wiggins, and Brendan M. Rogers
Biogeosciences, 20, 2785–2804, https://doi.org/10.5194/bg-20-2785-2023, https://doi.org/10.5194/bg-20-2785-2023, 2023
Short summary
Short summary
Here we developed a new burned-area detection algorithm between 2001–2019 across Alaska and Canada at 500 m resolution. We estimate 2.37 Mha burned annually between 2001–2019 over the domain, emitting 79.3 Tg C per year, with a mean combustion rate of 3.13 kg C m−2. We found larger-fire years were generally associated with greater mean combustion. The burned-area and combustion datasets described here can be used for local- to continental-scale applications of boreal fire science.
V. Rachel Chimuka, Claude-Michel Nzotungicimpaye, and Kirsten Zickfeld
Biogeosciences, 20, 2283–2299, https://doi.org/10.5194/bg-20-2283-2023, https://doi.org/10.5194/bg-20-2283-2023, 2023
Short summary
Short summary
We propose a new method to quantify carbon cycle feedbacks under negative CO2 emissions. Our method isolates the lagged carbon cycle response to preceding positive emissions from the response to negative emissions. Our findings suggest that feedback parameters calculated with the novel approach are larger than those calculated with the conventional approach whereby carbon cycle inertia is not corrected for, with implications for the effectiveness of carbon dioxide removal in reducing CO2 levels.
Marcus Breil, Annabell Weber, and Joaquim G. Pinto
Biogeosciences, 20, 2237–2250, https://doi.org/10.5194/bg-20-2237-2023, https://doi.org/10.5194/bg-20-2237-2023, 2023
Short summary
Short summary
A promising strategy for mitigating burdens of heat extremes in Europe is to replace dark coniferous forests with brighter deciduous forests. The consequence of this would be reduced absorption of solar radiation, which should reduce the intensities of heat periods. In this study, we show that deciduous forests have a certain cooling effect on heat period intensities in Europe. However, the magnitude of the temperature reduction is quite small.
Marcus Breil, Vanessa Schneider, and Joaquim Pinto
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-94, https://doi.org/10.5194/bg-2023-94, 2023
Revised manuscript accepted for BG
Short summary
Short summary
The general impact of afforestation on the regional climate conditions in Europe during the period 1986–2015 is investigated. For this purpose, a regional climate model simulation is performed, in which afforestation during this period is considered, and results are compared to a simulation in which this is not the case. Results show that afforestation had discernible impacts on the climate change signal in Europe, which may have mitigated the local warming trend especially in summer in Europe.
Gesche Blume-Werry, Jonatan Klaminder, Eveline J. Krab, and Sylvain Monteux
Biogeosciences, 20, 1979–1990, https://doi.org/10.5194/bg-20-1979-2023, https://doi.org/10.5194/bg-20-1979-2023, 2023
Short summary
Short summary
Northern soils store a lot of carbon. Most research has focused on how this carbon storage is regulated by cold temperatures. However, it is soil organisms, from minute bacteria to large earthworms, that decompose the organic material. Novel soil organisms from further south could increase decomposition rates more than climate change does and lead to carbon losses. We therefore advocate for including soil organisms when predicting the fate of soil functions in warming northern ecosystems.
Koramanghat Unnikrishnan Jayakrishnan and Govindasamy Bala
Biogeosciences, 20, 1863–1877, https://doi.org/10.5194/bg-20-1863-2023, https://doi.org/10.5194/bg-20-1863-2023, 2023
Short summary
Short summary
Afforestation and reducing fossil fuel emissions are two important mitigation strategies to reduce the amount of global warming. Our work shows that reducing fossil fuel emissions is relatively more effective than afforestation for the same amount of carbon removed from the atmosphere. However, understanding of the processes that govern the biophysical effects of afforestation should be improved before considering our results for climate policy.
Jens Hartmann, Niels Suitner, Carl Lim, Julieta Schneider, Laura Marín-Samper, Javier Arístegui, Phil Renforth, Jan Taucher, and Ulf Riebesell
Biogeosciences, 20, 781–802, https://doi.org/10.5194/bg-20-781-2023, https://doi.org/10.5194/bg-20-781-2023, 2023
Short summary
Short summary
CO2 can be stored in the ocean via increasing alkalinity of ocean water. Alkalinity can be created via dissolution of alkaline materials, like limestone or soda. Presented research studies boundaries for increasing alkalinity in seawater. The best way to increase alkalinity was found using an equilibrated solution, for example as produced from reactors. Adding particles for dissolution into seawater on the other hand produces the risk of losing alkalinity and degassing of CO2 to the atmosphere.
Damian L. Arévalo-Martínez, Amir Haroon, Hermann W. Bange, Ercan Erkul, Marion Jegen, Nils Moosdorf, Jens Schneider von Deimling, Christian Berndt, Michael Ernst Böttcher, Jasper Hoffmann, Volker Liebetrau, Ulf Mallast, Gudrun Massmann, Aaron Micallef, Holly A. Michael, Hendrik Paasche, Wolfgang Rabbel, Isaac Santos, Jan Scholten, Katrin Schwalenberg, Beata Szymczycha, Ariel T. Thomas, Joonas J. Virtasalo, Hannelore Waska, and Bradley A. Weymer
Biogeosciences, 20, 647–662, https://doi.org/10.5194/bg-20-647-2023, https://doi.org/10.5194/bg-20-647-2023, 2023
Short summary
Short summary
Groundwater flows at the land–ocean transition and the extent of freshened groundwater below the seafloor are increasingly relevant in marine sciences, both because they are a highly uncertain term of biogeochemical budgets and due to the emerging interest in the latter as a resource. Here, we discuss our perspectives on future research directions to better understand land–ocean connectivity through groundwater and its potential responses to natural and human-induced environmental changes.
Morgan Sparey, Peter Cox, and Mark S. Williamson
Biogeosciences, 20, 451–488, https://doi.org/10.5194/bg-20-451-2023, https://doi.org/10.5194/bg-20-451-2023, 2023
Short summary
Short summary
Accurate climate models are vital for mitigating climate change; however, projections often disagree. Using Köppen–Geiger bioclimate classifications we show that CMIP6 climate models agree well on the fraction of global land surface that will change classification per degree of global warming. We find that 13 % of land will change climate per degree of warming from 1 to 3 K; thus, stabilising warming at 1.5 rather than 2 K would save over 7.5 million square kilometres from bioclimatic change.
Huanhuan Wang, Chao Yue, and Sebastiaan Luyssaert
Biogeosciences, 20, 75–92, https://doi.org/10.5194/bg-20-75-2023, https://doi.org/10.5194/bg-20-75-2023, 2023
Short summary
Short summary
This study provided a synthesis of three influential methods to quantify afforestation impact on surface temperature. Results showed that actual effect following afforestation was highly dependent on afforestation fraction. When full afforestation is assumed, the actual effect approaches the potential effect. We provided evidence the afforestation faction is a key factor in reconciling different methods and emphasized that it should be considered for surface cooling impacts in policy evaluation.
Ryan S. Padrón, Lukas Gudmundsson, Laibao Liu, Vincent Humphrey, and Sonia I. Seneviratne
Biogeosciences, 19, 5435–5448, https://doi.org/10.5194/bg-19-5435-2022, https://doi.org/10.5194/bg-19-5435-2022, 2022
Short summary
Short summary
The answer to how much carbon land ecosystems are projected to remove from the atmosphere until 2100 is different for each Earth system model. We find that differences across models are primarily explained by the annual land carbon sink dependence on temperature and soil moisture, followed by the dependence on CO2 air concentration, and by average climate conditions. Our insights on why each model projects a relatively high or low land carbon sink can help to reduce the underlying uncertainty.
Julian Gutt, Stefanie Arndt, David Keith Alan Barnes, Horst Bornemann, Thomas Brey, Olaf Eisen, Hauke Flores, Huw Griffiths, Christian Haas, Stefan Hain, Tore Hattermann, Christoph Held, Mario Hoppema, Enrique Isla, Markus Janout, Céline Le Bohec, Heike Link, Felix Christopher Mark, Sebastien Moreau, Scarlett Trimborn, Ilse van Opzeeland, Hans-Otto Pörtner, Fokje Schaafsma, Katharina Teschke, Sandra Tippenhauer, Anton Van de Putte, Mia Wege, Daniel Zitterbart, and Dieter Piepenburg
Biogeosciences, 19, 5313–5342, https://doi.org/10.5194/bg-19-5313-2022, https://doi.org/10.5194/bg-19-5313-2022, 2022
Short summary
Short summary
Long-term ecological observations are key to assess, understand and predict impacts of environmental change on biotas. We present a multidisciplinary framework for such largely lacking investigations in the East Antarctic Southern Ocean, combined with case studies, experimental and modelling work. As climate change is still minor here but is projected to start soon, the timely implementation of this framework provides the unique opportunity to document its ecological impacts from the very onset.
Daniel François, Adina Paytan, Olga Maria Oliveira de Araújo, Ricardo Tadeu Lopes, and Cátia Fernandes Barbosa
Biogeosciences, 19, 5269–5285, https://doi.org/10.5194/bg-19-5269-2022, https://doi.org/10.5194/bg-19-5269-2022, 2022
Short summary
Short summary
Our analysis revealed that under the two most conservative acidification projections foraminifera assemblages did not display considerable changes. However, a significant decrease in species richness was observed when pH decreases to 7.7 pH units, indicating adverse effects under high-acidification scenarios. A micro-CT analysis revealed that calcified tests of Archaias angulatus were of lower density in low pH, suggesting no acclimation capacity for this species.
Leander Moesinger, Ruxandra-Maria Zotta, Robin van der Schalie, Tracy Scanlon, Richard de Jeu, and Wouter Dorigo
Biogeosciences, 19, 5107–5123, https://doi.org/10.5194/bg-19-5107-2022, https://doi.org/10.5194/bg-19-5107-2022, 2022
Short summary
Short summary
The standardized vegetation optical depth index (SVODI) can be used to monitor the vegetation condition, such as whether the vegetation is unusually dry or wet. SVODI has global coverage, spans the past 3 decades and is derived from multiple spaceborne passive microwave sensors of that period. SVODI is based on a new probabilistic merging method that allows the merging of normally distributed data even if the data are not gap-free.
Rebecca M. Varney, Sarah E. Chadburn, Eleanor J. Burke, and Peter M. Cox
Biogeosciences, 19, 4671–4704, https://doi.org/10.5194/bg-19-4671-2022, https://doi.org/10.5194/bg-19-4671-2022, 2022
Short summary
Short summary
Soil carbon is the Earth’s largest terrestrial carbon store, and the response to climate change represents one of the key uncertainties in obtaining accurate global carbon budgets required to successfully militate against climate change. The ability of climate models to simulate present-day soil carbon is therefore vital. This study assesses soil carbon simulation in the latest ensemble of models which allows key areas for future model development to be identified.
Laurent Bopp, Olivier Aumont, Lester Kwiatkowski, Corentin Clerc, Léonard Dupont, Christian Ethé, Thomas Gorgues, Roland Séférian, and Alessandro Tagliabue
Biogeosciences, 19, 4267–4285, https://doi.org/10.5194/bg-19-4267-2022, https://doi.org/10.5194/bg-19-4267-2022, 2022
Short summary
Short summary
The impact of anthropogenic climate change on the biological production of phytoplankton in the ocean is a cause for concern because its evolution could affect the response of marine ecosystems to climate change. Here, we identify biological N fixation and its response to future climate change as a key process in shaping the future evolution of marine phytoplankton production. Our results show that further study of how this nitrogen fixation responds to environmental change is essential.
Negar Vakilifard, Richard G. Williams, Philip B. Holden, Katherine Turner, Neil R. Edwards, and David J. Beerling
Biogeosciences, 19, 4249–4265, https://doi.org/10.5194/bg-19-4249-2022, https://doi.org/10.5194/bg-19-4249-2022, 2022
Short summary
Short summary
To remain within the Paris climate agreement, there is an increasing need to develop and implement carbon capture and sequestration techniques. The global climate benefits of implementing negative emission technologies over the next century are assessed using an Earth system model covering a wide range of plausible climate states. In some model realisations, there is continued warming after emissions cease. This continued warming is avoided if negative emissions are incorporated.
Marco Reale, Gianpiero Cossarini, Paolo Lazzari, Tomas Lovato, Giorgio Bolzon, Simona Masina, Cosimo Solidoro, and Stefano Salon
Biogeosciences, 19, 4035–4065, https://doi.org/10.5194/bg-19-4035-2022, https://doi.org/10.5194/bg-19-4035-2022, 2022
Short summary
Short summary
Future projections under the RCP8.5 and RCP4.5 emission scenarios of the Mediterranean Sea biogeochemistry at the end of the 21st century show different levels of decline in nutrients, oxygen and biomasses and an acidification of the water column. The signal intensity is stronger under RCP8.5 and in the eastern Mediterranean. Under RCP4.5, after the second half of the 21st century, biogeochemical variables show a recovery of the values observed at the beginning of the investigated period.
Charly A. Moras, Lennart T. Bach, Tyler Cyronak, Renaud Joannes-Boyau, and Kai G. Schulz
Biogeosciences, 19, 3537–3557, https://doi.org/10.5194/bg-19-3537-2022, https://doi.org/10.5194/bg-19-3537-2022, 2022
Short summary
Short summary
This research presents the first laboratory results of quick and hydrated lime dissolution in natural seawater. These two minerals are of great interest for ocean alkalinity enhancement, a strategy aiming to decrease atmospheric CO2 concentrations. Following the dissolution of these minerals, we identified several hurdles and presented ways to avoid them or completely negate them. Finally, we proceeded to various simulations in today’s oceans to implement the strategy at its highest potential.
Taraka Davies-Barnard, Sönke Zaehle, and Pierre Friedlingstein
Biogeosciences, 19, 3491–3503, https://doi.org/10.5194/bg-19-3491-2022, https://doi.org/10.5194/bg-19-3491-2022, 2022
Short summary
Short summary
Biological nitrogen fixation is the largest natural input of new nitrogen onto land. Earth system models mainly represent global total terrestrial biological nitrogen fixation within observational uncertainties but overestimate tropical fixation. The model range of increase in biological nitrogen fixation in the SSP3-7.0 scenario is 3 % to 87 %. While biological nitrogen fixation is a key source of new nitrogen, its predictive power for net primary productivity in models is limited.
Niel Verbrigghe, Niki I. W. Leblans, Bjarni D. Sigurdsson, Sara Vicca, Chao Fang, Lucia Fuchslueger, Jennifer L. Soong, James T. Weedon, Christopher Poeplau, Cristina Ariza-Carricondo, Michael Bahn, Bertrand Guenet, Per Gundersen, Gunnhildur E. Gunnarsdóttir, Thomas Kätterer, Zhanfeng Liu, Marja Maljanen, Sara Marañón-Jiménez, Kathiravan Meeran, Edda S. Oddsdóttir, Ivika Ostonen, Josep Peñuelas, Andreas Richter, Jordi Sardans, Páll Sigurðsson, Margaret S. Torn, Peter M. Van Bodegom, Erik Verbruggen, Tom W. N. Walker, Håkan Wallander, and Ivan A. Janssens
Biogeosciences, 19, 3381–3393, https://doi.org/10.5194/bg-19-3381-2022, https://doi.org/10.5194/bg-19-3381-2022, 2022
Short summary
Short summary
In subarctic grassland on a geothermal warming gradient, we found large reductions in topsoil carbon stocks, with carbon stocks linearly declining with warming intensity. Most importantly, however, we observed that soil carbon stocks stabilised within 5 years of warming and remained unaffected by warming thereafter, even after > 50 years of warming. Moreover, in contrast to the large topsoil carbon losses, subsoil carbon stocks remained unaffected after > 50 years of soil warming.
Roberto Pilli, Ramdane Alkama, Alessandro Cescatti, Werner A. Kurz, and Giacomo Grassi
Biogeosciences, 19, 3263–3284, https://doi.org/10.5194/bg-19-3263-2022, https://doi.org/10.5194/bg-19-3263-2022, 2022
Short summary
Short summary
To become carbon neutral by 2050, the European Union (EU27) forest C sink should increase to −450 Mt CO2 yr-1. Our study highlights that under current management practices (i.e. excluding any policy scenario) the forest C sink of the EU27 member states and the UK may decrease to about −250 Mt CO2eq yr-1 in 2050. The expected impacts of future climate change, however, add a considerable uncertainty, potentially nearly doubling or halving the sink associated with forest management.
Johnathan Daniel Maxey, Neil David Hartstein, Aazani Mujahid, and Moritz Müller
Biogeosciences, 19, 3131–3150, https://doi.org/10.5194/bg-19-3131-2022, https://doi.org/10.5194/bg-19-3131-2022, 2022
Short summary
Short summary
Deep coastal inlets are important sites for regulating land-based organic pollution before it enters coastal oceans. This study focused on how large climate forces, rainfall, and river flow impact organic loading and oxygen conditions in a coastal inlet in Tasmania. Increases in rainfall were linked to higher organic loading and lower oxygen in basin waters. Finally we observed a significant correlation between the Southern Annular Mode and oxygen concentrations in the system's basin waters.
Guang Gao, Tifeng Wang, Jiazhen Sun, Xin Zhao, Lifang Wang, Xianghui Guo, and Kunshan Gao
Biogeosciences, 19, 2795–2804, https://doi.org/10.5194/bg-19-2795-2022, https://doi.org/10.5194/bg-19-2795-2022, 2022
Short summary
Short summary
After conducting large-scale deck-incubation experiments, we found that seawater acidification (SA) increased primary production (PP) in coastal waters but reduced it in pelagic zones, which is mainly regulated by local pH, light intensity, salinity, and community structure. In future oceans, SA combined with decreased upward transports of nutrients may synergistically reduce PP in pelagic zones.
Joko Sampurno, Valentin Vallaeys, Randy Ardianto, and Emmanuel Hanert
Biogeosciences, 19, 2741–2757, https://doi.org/10.5194/bg-19-2741-2022, https://doi.org/10.5194/bg-19-2741-2022, 2022
Short summary
Short summary
This study is the first assessment to evaluate the interactions between river discharges, tides, and storm surges and how they can drive compound flooding in the Kapuas River delta. We successfully created a realistic hydrodynamic model whose domain covers the land–sea continuum using a wetting–drying algorithm in a data-scarce environment. We then proposed a new method to delineate compound flooding hazard zones along the river channels based on the maximum water level profiles.
Svenja Dobbert, Roland Pape, and Jörg Löffler
Biogeosciences, 19, 1933–1958, https://doi.org/10.5194/bg-19-1933-2022, https://doi.org/10.5194/bg-19-1933-2022, 2022
Short summary
Short summary
Understanding how vegetation might respond to climate change is especially important in arctic–alpine ecosystems, where major shifts in shrub growth have been observed. We studied how such changes come to pass and how future changes might look by measuring hourly variations in the stem diameter of dwarf shrubs from one common species. From these data, we are able to discern information about growth mechanisms and can thus show the complexity of shrub growth and micro-environment relations.
Jody Daniel, Rebecca C. Rooney, and Derek T. Robinson
Biogeosciences, 19, 1547–1570, https://doi.org/10.5194/bg-19-1547-2022, https://doi.org/10.5194/bg-19-1547-2022, 2022
Short summary
Short summary
The threat posed by climate change to prairie pothole wetlands is well documented, but gaps remain in our ability to make meaningful predictions about how prairie pothole wetlands will respond. We integrate aspects of topography, land cover/land use and climate to model the permanence class of tens of thousands of wetlands at the western edge of the Prairie Pothole Region.
Ádám T. Kocsis, Qianshuo Zhao, Mark J. Costello, and Wolfgang Kiessling
Biogeosciences, 18, 6567–6578, https://doi.org/10.5194/bg-18-6567-2021, https://doi.org/10.5194/bg-18-6567-2021, 2021
Short summary
Short summary
Biodiversity is under threat from the effects of global warming, and assessing the effects of climate change on areas of high species richness is of prime importance to conservation. Terrestrial and freshwater rich spots have been and will be less affected by climate change than other areas. However, marine rich spots of biodiversity are expected to experience more pronounced warming.
Rob Wilson, Kathy Allen, Patrick Baker, Gretel Boswijk, Brendan Buckley, Edward Cook, Rosanne D'Arrigo, Dan Druckenbrod, Anthony Fowler, Margaux Grandjean, Paul Krusic, and Jonathan Palmer
Biogeosciences, 18, 6393–6421, https://doi.org/10.5194/bg-18-6393-2021, https://doi.org/10.5194/bg-18-6393-2021, 2021
Short summary
Short summary
We explore blue intensity (BI) – a low-cost method for measuring ring density – to enhance palaeoclimatology in Australasia. Calibration experiments, using several conifer species from Tasmania and New Zealand, model 50–80 % of the summer temperature variance. The implications of these results have profound consequences for high-resolution paleoclimatology in Australasia, as the speed and cheapness of BI generation could lead to a step change in our understanding of past climate in the region.
Alex R. Quijada-Rodriguez, Pou-Long Kuan, Po-Hsuan Sung, Mao-Ting Hsu, Garett J. P. Allen, Pung Pung Hwang, Yung-Che Tseng, and Dirk Weihrauch
Biogeosciences, 18, 6287–6300, https://doi.org/10.5194/bg-18-6287-2021, https://doi.org/10.5194/bg-18-6287-2021, 2021
Short summary
Short summary
Anthropogenic CO2 is chronically acidifying aquatic ecosystems. We aimed to determine the impact of future freshwater acidification on the physiology and behaviour of an important aquaculture crustacean, Chinese mitten crabs. We report that elevated freshwater CO2 levels lead to impairment of calcification, locomotor behaviour, and survival and reduced metabolism in this species. Results suggest that present-day calcifying invertebrates could be heavily affected by freshwater acidification.
Junrong Zha and Qianlai Zhuang
Biogeosciences, 18, 6245–6269, https://doi.org/10.5194/bg-18-6245-2021, https://doi.org/10.5194/bg-18-6245-2021, 2021
Short summary
Short summary
This study incorporated moss into an extant biogeochemistry model to simulate the role of moss in carbon dynamics in the Arctic. The interactions between higher plants and mosses and their competition for energy, water, and nutrients are considered in our study. We found that, compared with the previous model without moss, the new model estimated a much higher carbon accumulation in the region during the last century and this century.
Maria Belke-Brea, Florent Domine, Ghislain Picard, Mathieu Barrere, and Laurent Arnaud
Biogeosciences, 18, 5851–5869, https://doi.org/10.5194/bg-18-5851-2021, https://doi.org/10.5194/bg-18-5851-2021, 2021
Short summary
Short summary
Expanding shrubs in the Arctic change snowpacks into a mix of snow, impurities and buried branches. Snow is a translucent medium into which light penetrates and gets partly absorbed by branches or impurities. Measurements of light attenuation in snow in Northern Quebec, Canada, showed (1) black-carbon-dominated light attenuation in snowpacks without shrubs and (2) buried branches influence radiation attenuation in snow locally, leading to melting and pockets of large crystals close to branches.
Sazlina Salleh and Andrew McMinn
Biogeosciences, 18, 5313–5326, https://doi.org/10.5194/bg-18-5313-2021, https://doi.org/10.5194/bg-18-5313-2021, 2021
Short summary
Short summary
The benthic diatom communities in Tanjung Rhu, Malaysia, were regularly exposed to high light and temperature variability during the tidal cycle, resulting in low photosynthetic efficiency. We examined the impact of high temperatures on diatoms' photosynthetic capacities, and temperatures beyond 50 °C caused severe photoinhibition. At the same time, those diatoms exposed to temperatures of 40 °C did not show any sign of photoinhibition.
Cornelius Senf and Rupert Seidl
Biogeosciences, 18, 5223–5230, https://doi.org/10.5194/bg-18-5223-2021, https://doi.org/10.5194/bg-18-5223-2021, 2021
Short summary
Short summary
Europe was affected by an extreme drought in 2018. We show that this drought has increased forest disturbances across Europe, especially central and eastern Europe. Disturbance levels observed 2018–2020 were the highest on record for 30 years. Increased forest disturbances were correlated with low moisture and high atmospheric water demand. The unprecedented impacts of the 2018 drought on forest disturbances demonstrate an urgent need to adapt Europe’s forests to a hotter and drier future.
Jessica L. McCarty, Juha Aalto, Ville-Veikko Paunu, Steve R. Arnold, Sabine Eckhardt, Zbigniew Klimont, Justin J. Fain, Nikolaos Evangeliou, Ari Venäläinen, Nadezhda M. Tchebakova, Elena I. Parfenova, Kaarle Kupiainen, Amber J. Soja, Lin Huang, and Simon Wilson
Biogeosciences, 18, 5053–5083, https://doi.org/10.5194/bg-18-5053-2021, https://doi.org/10.5194/bg-18-5053-2021, 2021
Short summary
Short summary
Fires, including extreme fire seasons, and fire emissions are more common in the Arctic. A review and synthesis of current scientific literature find climate change and human activity in the north are fuelling an emerging Arctic fire regime, causing more black carbon and methane emissions within the Arctic. Uncertainties persist in characterizing future fire landscapes, and thus emissions, as well as policy-relevant challenges in understanding, monitoring, and managing Arctic fire regimes.
Alexander J. Winkler, Ranga B. Myneni, Alexis Hannart, Stephen Sitch, Vanessa Haverd, Danica Lombardozzi, Vivek K. Arora, Julia Pongratz, Julia E. M. S. Nabel, Daniel S. Goll, Etsushi Kato, Hanqin Tian, Almut Arneth, Pierre Friedlingstein, Atul K. Jain, Sönke Zaehle, and Victor Brovkin
Biogeosciences, 18, 4985–5010, https://doi.org/10.5194/bg-18-4985-2021, https://doi.org/10.5194/bg-18-4985-2021, 2021
Short summary
Short summary
Satellite observations since the early 1980s show that Earth's greening trend is slowing down and that browning clusters have been emerging, especially in the last 2 decades. A collection of model simulations in conjunction with causal theory points at climatic changes as a key driver of vegetation changes in natural ecosystems. Most models underestimate the observed vegetation browning, especially in tropical rainforests, which could be due to an excessive CO2 fertilization effect in models.
Vincent Niderkorn, Annette Morvan-Bertrand, Aline Le Morvan, Angela Augusti, Marie-Laure Decau, and Catherine Picon-Cochard
Biogeosciences, 18, 4841–4853, https://doi.org/10.5194/bg-18-4841-2021, https://doi.org/10.5194/bg-18-4841-2021, 2021
Short summary
Short summary
Climate change can change vegetation characteristics in grasslands with a potential impact on forage chemical composition and quality, as well as its use by ruminants. Using controlled conditions mimicking a future climatic scenario, we show that forage quality and ruminant digestion are affected in opposite ways by elevated atmospheric CO2 and an extreme event (heat wave, severe drought), indicating that different factors of climate change have to be considered together.
Verónica Pancotto, David Holl, Julio Escobar, María Florencia Castagnani, and Lars Kutzbach
Biogeosciences, 18, 4817–4839, https://doi.org/10.5194/bg-18-4817-2021, https://doi.org/10.5194/bg-18-4817-2021, 2021
Short summary
Short summary
We investigated the response of a wetland plant community to elevated temperature conditions in a cushion bog on Tierra del Fuego, Argentina. We measured carbon dioxide fluxes at experimentally warmed plots and at control plots. Warmed plant communities sequestered between 55 % and 85 % less carbon dioxide than untreated control cushions over the main growing season. Our results suggest that even moderate future warming could decrease the carbon sink function of austral cushion bogs.
Melissa A. Ward, Tessa M. Hill, Chelsey Souza, Tessa Filipczyk, Aurora M. Ricart, Sarah Merolla, Lena R. Capece, Brady C O'Donnell, Kristen Elsmore, Walter C. Oechel, and Kathryn M. Beheshti
Biogeosciences, 18, 4717–4732, https://doi.org/10.5194/bg-18-4717-2021, https://doi.org/10.5194/bg-18-4717-2021, 2021
Short summary
Short summary
Salt marshes and seagrass meadows ("blue carbon" habitats) can sequester and store high levels of organic carbon (OC), helping to mitigate climate change. In California blue carbon sediments, we quantified OC storage and exchange between these habitats. We find that (1) these salt marshes store about twice as much OC as seagrass meadows do and (2), while OC from seagrass meadows is deposited into neighboring salt marshes, little of this material is sequestered as "long-term" carbon.
Damien Couespel, Marina Lévy, and Laurent Bopp
Biogeosciences, 18, 4321–4349, https://doi.org/10.5194/bg-18-4321-2021, https://doi.org/10.5194/bg-18-4321-2021, 2021
Short summary
Short summary
An alarming consequence of climate change is the oceanic primary production decline projected by Earth system models. These coarse-resolution models parameterize oceanic eddies. Here, idealized simulations of global warming with increasing resolution show that the decline in primary production in the eddy-resolved simulations is half as large as in the eddy-parameterized simulations. This stems from the high sensitivity of the subsurface nutrient transport to model resolution.
Wu Ma, Lu Zhai, Alexandria Pivovaroff, Jacquelyn Shuman, Polly Buotte, Junyan Ding, Bradley Christoffersen, Ryan Knox, Max Moritz, Rosie A. Fisher, Charles D. Koven, Lara Kueppers, and Chonggang Xu
Biogeosciences, 18, 4005–4020, https://doi.org/10.5194/bg-18-4005-2021, https://doi.org/10.5194/bg-18-4005-2021, 2021
Short summary
Short summary
We use a hydrodynamic demographic vegetation model to estimate live fuel moisture dynamics of chaparral shrubs, a dominant vegetation type in fire-prone southern California. Our results suggest that multivariate climate change could cause a significant net reduction in live fuel moisture and thus exacerbate future wildfire danger in chaparral shrub systems.
Bertold Mariën, Inge Dox, Hans J. De Boeck, Patrick Willems, Sebastien Leys, Dimitri Papadimitriou, and Matteo Campioli
Biogeosciences, 18, 3309–3330, https://doi.org/10.5194/bg-18-3309-2021, https://doi.org/10.5194/bg-18-3309-2021, 2021
Short summary
Short summary
The drivers of the onset of autumn leaf senescence for several deciduous tree species are still unclear. Therefore, we addressed (i) if drought impacts the timing of autumn leaf senescence and (ii) if the relationship between drought and autumn leaf senescence depends on the tree species. Our study suggests that the timing of autumn leaf senescence is conservative across years and species and even independent of drought stress.
Anna Katavouta and Richard G. Williams
Biogeosciences, 18, 3189–3218, https://doi.org/10.5194/bg-18-3189-2021, https://doi.org/10.5194/bg-18-3189-2021, 2021
Short summary
Short summary
Diagnostics of the latest-generation Earth system models reveal the ocean will continue to absorb a large fraction of the anthropogenic carbon released to the atmosphere in the next century, with the Atlantic Ocean storing a large amount of this carbon relative to its size. The ability of the ocean to absorb carbon will reduce in the future as the ocean warms and acidifies. This reduction is larger in the Atlantic Ocean due to a weakening of the meridional overturning with changes in climate.
Cited articles
Arnosti, C.: A new method for measuring polysaccharide hydrolysis rates in marine environments, Org. Geochem., 25, 105–115, 1996.
Arnosti, C.: Microbial extracellular enzymes and the marine carbon cycle., edited by: Carlson, C. A. G. S. J., Annu. Rev. Mar. Sci., 3, 401–425, https://doi.org/10.1146/annurev-marine-120709-142731, 2011.
Azam, F. and Ammerman, W.: Cycling of organic matter by bacterioplankton in pelagic marine ecosystems: microenvironmental considerations, in: Microenvironmental Considerations, Flows of Energy and Materials in Marine Ecosystems, edited by: Fasham, M. J. R., Plenum Publishing Company, New York, 345–360, 1984.
Azam, F. and Cho, B. C.: Bacterial utilization of organic matter in the sea, Symp. Soc. Gen. Microbi., 41, 261–281, 1987.
Azam, F., Fenche, T., Field, J., Gray, J., Meyer-Reil, L., and Thingstad, F.: The ecological role of water-column microbes in the sea, Mar. Ecol.-Prog. Ser., 10, 257–263, 1983.
Baker, J. O. and Prescott, J. M.: Aeromonas aminopeptidase: pH dependence and a transition-state-analogue inhibitor, Biochemistry, 22, 5322–5331, 1983.
Benner, R.: Chemical composition and reactivity, in: Biogeochemistry of Marine Dissolved Organic Matter, edited by: Hansell, D. and Carlson, C., Academic Press, California, USA, 59–91, 2002.
Benner, R., Pakulski, J. D., McCarthy, M., Hedges, J. I., and Hatcher, P. G.: Bulk chemical characteristics of dissolved organic matter in the ocean, Science, 255, 1561–1564, 1992.
Boominadhan, U., Rajakumar, R., Sivakumaar, P. K. V., and Joe, M. M.: Optimization of protease enzyme production using Bacillus sp. isolated from different wastes, Bot. Res. Int., 2, 83–87, 2009.
Burrell, T. J., Maas, E. W., Hulston, D. A., and Law, C. S.: Bacterial abundance, processes and diversity responses to acidification at a coastal CO2 vent, FEMS Microbiol. Lett., 362, 1–8,, https://doi.org/10.1093/femsle/fnv154, 2015.
Button, D. K. and Robertson, B. R.: Use of high-resolution flow cytometry to determine the activity and distribution of aquatic bacteria, in: Handbook of Methods in Aquatic Microbial Ecology, edited by: Kemp, P. F., Sherr, B. F., Sherr, E. B., and Cole, J. J., Lewis Publishers, CRC Press LLC, Florida, USA, 163–173, 1993.
Chen, C. Y. and Durbin, E. G.: Effects of pH on the growth and carbon uptake of marine phytoplankton, Mar. Ecol.-Prog. Ser., 109, 83–94, 1994.
Chróst, R. J.: Characterization and significance of β-glucosidase activity in lake water, Limnol. Oceanogr., 34, 660–672, 1989.
Cornwall, C. E and Hurd, C. L.: Experimental design in ocean acidification research: problems and solutions, ICES J. Mar. Sci., 73, 572–581, https://doi.org/10.1093/icesjms/fsv118, 2015.
Cunha, A., Almeida, A., Coelho, F., Gomes, N., Oliveira, V., and Santos, A.: Bacterial extracellular enzymatic activity in globally changing aquatic ecosystems, Appl. Microbiol. Biot., 13, 978–984, 2010.
Desmarais, W. T., Bienvenue, D. L., Bzymek, K. P., Holz, R. C., Petsko, G. A., and Ringe, D.: The 1.20 A resolution crystal structure of the aminopeptidase from Aeromonas proteolytica complexed with Tris: A tale of buffer inhibition, Structure, 10, 1063–1072, 2002.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to Best Practices for Ocean CO2 Measurements, PICES Special Publication, 3, 2007.
Dixon, M.: The effect of pH on the affinities of enzymes for substrates and inhibitors, Biochem. J., 55, 161–170, 1953.
Emerson, S. and Hedges, J.: Carbonate chemistry, in: Chemical Oceanography and the Marine Carbon Cycle, Cambridge University Press, 103–132, 2008.
Endo, H., Yoshimura, T., Kataoka, T., and Suzuki, K.: Effects of CO2 and iron availability on phytoplankton and eubacterial community compositions in the northwest subarctic Pacific, J. Exp. Mar. Biol. Ecol., 439, 160–175, https://doi.org/10.1016/j.jembe.2012.11.003, 2013.
Endres, S., Unger, J., Wannicke, N., Nausch, M., Voss, M., and Engel, A.: Response of Nodularia spumigena to pCO2 – Part 2: Exudation and extracellular enzyme activities, Biogeosciences, 10, 567–582, https://doi.org/10.5194/bg-10-567-2013, 2013.
Endres, S., Galgani, L., Riebesell, U., Schulz, K.-G. and Engel, A.: Stimulated bacterial growth under elevated pCO2: results from an off-shore mesocosm study, PLoS One, 9, 1–8, 2014.
Engel, A.: Direct relationship between CO2 uptake and transparent exopolymer particles production in natural phytoplankton, J. Plankton Res., 24, 49–53, https://doi.org/10.1093/plankt/24.1.49, 2002.
Engel, A., Delille, B., Jacquet, S., Riebesell, U., Rochelle-Newall, E., Terbruggen, A., and Zondervan, I.: Transparent exopolymer particles and dissolved organic carbon production by Emiliania huxleyi exposed to different CO2 concentrations: a mesocosm experiment, Aquat. Microb. Ecol., 34, 93–104, https://doi.org/10.3354/ame034093, 2004.
Engel, A., Schulz, K. G., Riebesell, U., Bellerby, R., Delille, B., and Schartau, M.: Effects of CO2 on particle size distribution and phytoplankton abundance during a mesocosm bloom experiment (PeECE II), Biogeosciences, 5, 509–521, https://doi.org/10.5194/bg-5-509-2008, 2008.
Engel, A., Piontek, J., Grossart, H.-P., Riebesell, U., Schulz, K., and Sperling, M.: Impact of CO2 enrichment on organic matter dynamics during nutrient induced coastal phytoplankton blooms, J. Plankton Res., 36, 641–657, https://doi.org/10.1093/plankt/fbt125, 2014.
Gattuso, J.-P. and Lavigne, H.: Technical Note: Approaches and software tools to investigate the impact of ocean acidification, Biogeosciences, 6, 2121–2133, https://doi.org/10.5194/bg-6-2121-2009, 2009.
Grossart, H. P., Allgaier, M., Passow, U., and Riebesell, U.: Testing the effect of CO2 concentration on the dynamics of marine heterotrophic bacterioplankton, Limnol. Oceanogr., 51, 1–11, 2006.
Hall, J., Safi, K., and Cumming, A.: Role of microzooplankton grazers in the subtropical and subantarctic waters to the east of New Zealand, New Zeal. J. Mar. Fresh., 38, 91–101, https://doi.org/10.1080/00288330.2004.9517221, 2004.
Hoffmann, L. J., Breitbarth, E., McGraw, C. M., Law, C. S., Currie, K. I., and Hunter, K. A.: A trace-metal clean, pH-controlled incubator system for ocean acidification incubation studies, Limnol. Oceanogr., 11, 53–61, https://doi.org/10.4319/lom.2013.11.53, 2013.
Hoppe, C. J. M., Langer, G., and Rost, B.: Emiliania huxleyi shows identical responses to elevated pCO2 in TA and DIC manipulations, J. Exp. Mar. Biol. Ecol., 406, 54–62, https://doi.org/10.1016/j.jembe.2011.06.008, 2011.
Hoppe, H. G.: Significance of exoenzymatic activities in the ecology of brackish water: measurements by means of methylumbelliferyl-substrates, Mar. Ecol.-Prog. Ser., 11, 299–308, 1983.
Hoppe, H. G.: Use of fluorogenic model substrates for extracellular enzyme activity (EEA) measurement of bacteria., in: Handbook of Methods in Aquatic Microbial Ecology, edited by: Kemp, P. F., Sherr, B. F., Sherr, E. B., and Cole, J. J., Lewis Publ. Boca Raton, 423-431, 1993.
Houlsby, R. D., Ghajar, M., and Chavez, G.: Antimicrobial activity of borate-buffered solutions, Antimicrob. Agents Ch., 29, 803–806, 1986.
Hurd, C. L., Hepburn, C. D., Currie, K. I., Raven, J. A., and Hunter, K. A.: Testing the effects of ocean acidification on algal metabolism: considerations for experimental designs, J. Phycol., 45, 1236–1251, https://doi.org/10.1111/j.1529-8817.2009.00768.x, 2009.
IGBP-IOC-SCOR: Ocean acidification summary for policymakers, in: Third Symposium on the Ocean in a High-CO2 World, International Geosphere Programme, Stockholm, Sweden, 20 October, 1–24, 2013.
Iglesias-Rodriguez, M. D., Buitenhuis, E. T., Raven, J. A., Schofield, O., Poulton, A. J., Gibbs, S., Halloran, P. R., and de Baar, H. J. W.: Response to Comment on “Phytoplankton Calcification in a High-CO2 World”, Science, 322, 15–16, 2008.
IPCC: IPCC 2013: Summary for policymakers, in Climate Change 2013: The Physical Science Basis. Contribution of Working Group 1 to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattnher, G. K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P., Cambridge Univeristy Press, Unitied Kingdom and New York, NY, USA, 1–33, 2013.
Kepkay, P. E. and Johnson, B. D.: Coagulation on bubbles allows microbial respiration of oceanic dissolved organic-carbon, Nature, 338, 63–65, https://doi.org/10.1038/338063a0, 1989.
Kim, S. J. and Hoppe, H. G.: Microbial extracellular enzyme detection on agar plates by means of fluorogenic methylum-belliferyl-substrates, Colloq. Int. Bacteriol. Mar. Brest., Deuxième Colloque International de Bactériologie Marine, 1–8, 175–183, 1984.
Kirchman, D.: Measuring bacterial biomass production and growth rates from leucine incorporation in natural aquatic environments, Meth. Microbiol., 30, 227–237, 2001.
Law, B.: Transport and utilisation of proteins by bacteria, in: Microorganisms and Nitrogen Sources: Transport and Utilisation of Amino Acids, Peptides, Proteins, and Related Substrates, edited by: Payne, J. W., John Wiley & Sons Ltd, New York, 381–409, 1980.
Law, C. S., Breitbarth, E., Hoffmann, L. J., McGraw, C. M., Langlois, R. J., LaRoche, J., Marriner, A., and Safi, K. A.: No stimulation of nitrogen fixation by non-filamentous diazotrophs under elevated CO2 in the South Pacific, Glob. Change Biol., 18, 3004–3014, https://doi.org/10.1111/j.1365-2486.2012.02777.x, 2012.
Lebaron, P., Parthuisot, N., and Catala, P.: Comparison of blue nucleic acid dyes for flow cytometric enumeration of bacteria in aquatic systems, Appl. Environ. Microb., 64, 1725–1730, 1998.
Maas, E. W., Law, C. S., Hall, J. A., Pickmere, S., Currie, K. I., Chang, F. H., Voyles, K. M., and Caird, D.: Effect of ocean acidification on bacterial abundance, activity and diversity in the Ross Sea, Antarctica, Aquat. Microb. Ecol., 70, 1–15, https://doi.org/10.3354/ame01633, 2013.
Malcolm, R. E.: Assessment of phosphatase activity in soils, Soil Biol. Biochem., 15, 403–408, 1983.
McCarthy, M., Hedges, J., and Benner, R.: Major biochemical composition of dissolved high molecular weight organic matter in seawater, Mar. Chem., 55, 281–297, https://doi.org/10.1016/S0304-4203(96)00041-2, 1996.
Mead, J. A. R., Smith, J. N., and Williams, R. T.: Studies in detoxication. The biosynthesis of the glucuronides of umbelliferone and 4-methylumbelliferone and their use in fluorimetric determination of β-glucuronidase, Biochem. J., 61, 569–574, 1955.
McGraw, C. M., Cornwall, C. E., Reid, M. R., Currie, K. I., Hepburn, C. D., Boyd, P., Hurd, C. L., and Hunter, K. A.: An automated pH-controlled culture system for laboratory-based ocean acidification experiments, Limnol. Oceanogr., 8, 686–694, https://doi.org/10.4319/lom.2010.8.686, 2010.
Mopper, K., Zhou, J., Ramana, K. S., Passow, U., Damj, H. H., and Drapeaus, D. T.: The role of surface-active carbohydrates in the flocculation of a diatom bloom in a mesocosm, Deep-Sea Res. Pt. II, 42, 47–73, 1995.
Morris, A. and Foster, P.: The seasonal variation of dissolved organic carbon in the inshore waters of the Menai Strait in relation to primary production, Limnol. Oceanogr., 16, 987–989, 1971.
Münster, U.: Extracellular enzyme activity in eutrophic and polyhumic lakes, in: Microbial Enzymes in Aquatic Environments, edited by: Chróst, R., Springer, New York, 96–122, https://doi.org/10.1007/978-1-4612-3090-8_6, 1991.
Niemi, R. M. and Vepsäläinen, M.: Stability of the fluorogenic enzyme substrates and pH optima of enzyme activities in different Finnish soils, J. Microbiol. Meth., 60, 195–205, https://doi.org/10.1016/j.mimet.2004.09.010, 2005.
Orsi, B. A. and Tipton, K. F.: Kinetic analysis of progress curves, Method. Enzymol., 63, 159–183, 1979.
Passow, U.: The abiotic formation of TEP under different ocean acidification scenarios, Mar. Chem., 128–129, 72–80, 2012.
Piontek, J., Lunau, M., Händel, N., Borchard, C., Wurst, M., and Engel, A.: Acidification increases microbial polysaccharide degradation in the ocean, Biogeosciences, 7, 1615–1624, https://doi.org/10.5194/bg-7-1615-2010, 2010.
Piontek, J., Borchard, C., Sperling, M., Schulz, K. G., Riebesell, U., and Engel, A.: Response of bacterioplankton activity in an Arctic fjord system to elevated pCO2: results from a mesocosm perturbation study, Biogeosciences, 10, 297–314, https://doi.org/10.5194/bg-10-297-2013, 2013.
Riebesell, U.: Effects of CO2 enrichment on marine phytoplankton, J. Oceanogr., 60, 719–729, https://doi.org/10.1007/s10872-004-5764-z, 2004.
Riebesell, U. and Tortell, P. D.: Effects of ocean acidification on pelagic organisms and ecosystems, in: Ocean Acidification: Background and History, edited by: Gattuso, J. P. and Hansson, L., Oxford University Press, New York, 99–121, 2011.
Riebesell, U., Schulz, K., Bellerby, R., Botros, M., Fritsche, P., Meyerhoefer, M., Neill, C., Nondal, G., Oschlies, A., Wohlers, J., and Zoellner, E.: Enhanced biological carbon consumption in a high CO2 ocean, Nature, 450, 545–550, https://doi.org/10.1038/nature06267, 2007.
Riebesell, U., Fabry, V. J., Hansson, L., and Gattuso, J. P.: Guide to Best Practices for Ocean Acidification Research and Data Reporting, edited by: Riebesell, U., Fabry, V. J., Hansson, L., and Gattuso, J.-P., European Commission, Luxembourg, 2010.
Riley, G. A.: Organic aggregates in seawater and the dynamics of their formation and utilisation, Limnol. Oceanogr., 8, 372–381, 1963.
Rost, B., Zondervan, I., and Wolf-Gladrow, D.: Sensitivity of phytoplankton to future changes in ocean carbonate chemistry: current knowledge, contradictions and research directions, Mar. Ecol.-Prog. Ser., 373, 227–237, https://doi.org/10.3354/meps07776, 2008.
Saishin, N., Ueta, M., Wada, A., and Yamamoto, I.: Purification and characterization of α-galactosidase I from Bifidobacterium longum subsp. longum JCM 7052, J. Biol. Macromol., 10, 13–22, 2010.
Schulz, K. G., Barcelos e Ramos, J., Zeebe, R. E., and Riebesell, U.: CO2 perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations, Biogeosciences, 6, 2145–2153, https://doi.org/10.5194/bg-6-2145-2009, 2009.
Schulz, K. G., Bellerby, R. G. J., Brussaard, C. P. D., Büdenbender, J., Czerny, J., Engel, A., Fischer, M., Koch-Klavsen, S., Krug, S. A., Lischka, S., Ludwig, A., Meyerhöfer, M., Nondal, G., Silyakova, A., Stuhr, A., and Riebesell, U.: Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide, Biogeosciences, 10, 161–180, https://doi.org/10.5194/bg-10-161-2013, 2013.
Schuster, S. and Hernd, G. J.: Formation and significance of transparent exopolymeric particles in the northern Adriatic Sea, Mar. Ecol.-Prog. Ser., 124, 227–236, 1995.
Segschneider, J. and Bendtsen, J.: Temperature-dependent remineralisation in a warming ocean increases surface pCO2 through changes in marine ecosystem composition, Global Biogeochem. Cy., 27, 1214–1225, https://doi.org/10.1002/2013GB004684, 2013.
Shi, D., Xu, Y., and Morel, F. M. M.: Effects of the pH/pCO2 control method on medium chemistry and phytoplankton growth, Biogeosciences, 6, 1199–1207, https://doi.org/10.5194/bg-6-1199-2009, 2009.
Simon, M. and Azam, F.: Protein content and protein synthesis rates of planktonic marine bacteria, Mar. Ecol.-Prog. Ser., 51, 201–213, 1989.
Siu, N., Apple, J. K., and Moyer, C. L.: The effects of ocean acidity and elevated temperature on bacterioplankton community strucutre and meatbolism, Open J. Ecol., 4, 434–455, 2014.
Smith, D. C. and Azam, F.: A simple, economical method for measuring bacterial protein synthesis rates in seawater using 3H-leucine, Marine Microbial Food Webs, 6, 107–114, 1992.
Somville, M. and Billen, G.: A method for determining exoproteolytic activity in natural waters, Limnol. Oceanogr., 28, 190–193, 1983.
Teira, E., Fernández, A., Álvarez-Salgado, X., García-Martín, E., Serret, P., and Sobrino, C.: Response of two marine bacterial isolates to high CO2 concentration, Mar. Ecol.-Prog. Ser., 36, 27–36, 2012.
Tipton, K. F. and Dixon, H. B. F.: Effects of pH on enzymes, in: Enzyme Kinetics and Mechanism, Part A: Initial Rate and Inhibitor Methods, vol. 63, Academic Press, New York, 183–234, 1979.
Unanue, M., Ayo, B., Agis, M., Slezak, D., Herndl, G. J., and Iriberri, J.: Ectoenzymatic activity and uptake of monomers in marine bacterioplankton described by a biphasic kinetic model, Microb. Ecol., 37, 36–48, 1999.
Witt, V., Wild, C., Anthony, K. R. N., Diaz-Pulido, G., and Uthicke, S.: Effects of ocean acidification on microbial community composition of, and oxygen fluxes through, biofilms from the Great Barrier Reef, Environ. Microbiol., 13, 2976–2989, https://doi.org/10.1111/j.1462-2920.2011.02571.x, 2011.
Yague, E. and Estevez, M. P.: Purification and characterization of a β-glucosidase from Evernia prunastri, Eur. J. Biochem., 175, 627–632, 1988.
Zhou, J., Mopper, K., and Passow, U.: The role of surface-active carbohydrates in the formation of transparent exopolymer particles by bubble adsorption of seawater, Limnol. Oceanogr., 43, 1860–1871, 1998.
Short summary
Bacterial extracellular enzymes play a significant role in the degradation of organic matter in the open ocean. Using artificial fluorogenic substrates, this research highlights potential artefacts in the response of bacterial glucosidase and aminopeptidase to ocean acidification, and the effects of three different acidification techniques. We conclude that fluorogenic substrate degradation is affected by, or alters pH, and bubbling CO2 may lead to the overestimation of carbohydrate degradation.
Bacterial extracellular enzymes play a significant role in the degradation of organic matter in...
Altmetrics
Final-revised paper
Preprint