-
Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network Biogeosciences (IF 3.48) Pub Date : 2021-03-04 Tereza Novotná Jaroměřská; Jakub Trubač; Krzysztof Zawierucha; Lenka Vondrovicová; Miloslav Devetter; Jakub D. Žárský
Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates – tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning
-
Comparison of greenhouse gas fluxes from tropical forests and oil palm plantations on mineral soil Biogeosciences (IF 3.48) Pub Date : 2021-03-04 Julia Drewer; Melissa M. Leduning; Robert I. Griffiths; Tim Goodall; Peter E. Levy; Nicholas Cowan; Edward Comynn-Platt; Garry Hayman; Justin Sentian; Noreen Majalap; Ute M. Skiba
In Southeast Asia, oil palm (OP) plantations have largely replaced tropical forests. The impact of this shift in land use on greenhouse gas (GHG) fluxes remains highly uncertain, mainly due to a relatively small pool of available data. The aim of this study is to quantify differences of nitrous oxide (N2O) and methane (CH4) fluxes as well as soil carbon dioxide (CO2) respiration rates from logged forests
-
Microclimatic comparison of lichen heaths and shrubs: shrubification generates atmospheric heating but subsurface cooling during the growing season Biogeosciences (IF 3.48) Pub Date : 2021-03-04 Peter Aartsma; Johan Asplund; Arvid Odland; Stefanie Reinhardt; Hans Renssen
Lichen heaths are declining in abundance in alpine and Arctic areas partly due to an increasing competition with shrubs. This shift in vegetation types might have important consequences for the microclimate and climate on a larger scale. The aim of our study is to measure the difference in microclimatic conditions between lichen heaths and shrub vegetation during the growing season. With a paired plot
-
Rapid soil organic carbon decomposition in river systems: effects of the aquatic microbial community and hydrodynamical disturbance Biogeosciences (IF 3.48) Pub Date : 2021-03-03 Man Zhao; Liesbet Jacobs; Steven Bouillon; Gerard Govers
Different erosion processes deliver large amounts of terrestrial soil organic carbon (SOC) to rivers. Mounting evidence indicates that a significant fraction of this SOC, which displays a wide range of ages, is rapidly decomposed after entering the river system. The mechanisms explaining this rapid decomposition of previously stable SOC still remain unclear. In this study, we investigated the relative
-
What determines the sign of the evapotranspiration response to afforestation in European summer? Biogeosciences (IF 3.48) Pub Date : 2021-03-03 Marcus Breil; Edouard L. Davin; Diana Rechid
Uncertainties in the evapotranspiration response to afforestation constitute a major source of disagreement between model-based studies of the potential climate benefits of forests. Forests typically have higher evapotranspiration rates than grasslands in the tropics, but whether this is also the case in the midlatitudes is still debated. To explore this question and the underlying physical processes
-
Factors controlling the productivity of tropical Andean forests: climate and soil are more important than tree diversity Biogeosciences (IF 3.48) Pub Date : 2021-03-03 Jürgen Homeier; Christoph Leuschner
Theory predicts positive effects of species richness on the productivity of plant communities through complementary resource use and facilitative interactions between species. Results from manipulative experiments with tropical tree species indicate a positive diversity–productivity relationship (DPR), but the existing evidence from natural forests is scarce and contradictory. We studied forest aboveground
-
Spatial patterns of aboveground phytogenic Si stocks in a grass-dominated catchment – Results from UAS based high resolution remote sensing Biogeosciences (IF 3.48) Pub Date : 2021-03-03 Marc Wehrhan; Daniel Puppe; Danuta Kaczorek; Michael Sommer
Abstract. Various studies have been performed to quantify silicon (Si) stocks in plant biomass and related Si fluxes in terrestrial biogeosystems. Most of these studies were performed at relatively small plots with an intended low heterogeneity in soils and plant canopy composition, and results were extrapolated to larger spatial units up to global scale implicitly assuming similar environmental conditions
-
High greenhouse gas fluxes from peatlands under various disturbances in the Peruvian Amazon Biogeosciences (IF 3.48) Pub Date : 2021-03-03 Jaan Pärn; Kaido Soosaar; Thomas Schindler; Katerina Machacova; Waldemar Alegría Muñoz; Lizardo Fachín; José Luis Jibaja Aspajo; Robinson I. Negron-Juarez; Martin Maddison; Jhon Rengifo; Danika Journeth Garay Dinis; Adriana Gabriela Arista Oversluijs; Manuel Calixto Ávila Fucos; Rafael Chávez Vásquez; Ronal Huaje Wampuch; Edgar Peas García; Kristina Sohar; Segundo Cordova Horna; Tedi Pacheco Gómez;
Abstract. Amazonian peat swamp forests remove large amounts of carbon dioxide (CO2) but anaerobic decomposition of the peat produces methane (CH4). Drought or cultivation cuts down on the CH4 production but may increase the CO2 emission. Varying oxygen content in nitrogen-rich peat produces nitrous oxide (N2O). Despite the potentially tremendous changes, greenhouse gas emissions from peatlands under
-
Are there memory effects on greenhouse gas emissions (CO2, N2O and CH4) following grassland restoration? Biogeosciences (IF 3.48) Pub Date : 2021-03-02 Lutz Merbold; Charlotte Decock; Werner Eugster; Kathrin Fuchs; Benjamin Wolf; Nina Buchmann; Lukas Hörtnagl
A 5-year greenhouse gas (GHG) exchange study of the three major gas species (CO2, CH4 and N2O) from an intensively managed permanent grassland in Switzerland is presented. Measurements comprise 2 years (2010 and 2011) of manual static chamber measurements of CH4 and N2O, 5 years of continuous eddy covariance (EC) measurements (CO2–H2O – 2010–2014), and 3 years (2012–2014) of EC measurement of CH4 and
-
Impact of moderate energetic fine-scale dynamics on the phytoplankton community structure in the western Mediterranean Sea Biogeosciences (IF 3.48) Pub Date : 2021-03-02 Roxane Tzortzis; Andrea M. Doglioli; Stéphanie Barrillon; Anne A. Petrenko; Francesco d'Ovidio; Lloyd Izard; Melilotus Thyssen; Ananda Pascual; Bàrbara Barceló-Llull; Frédéric Cyr; Marc Tedetti; Nagib Bhairy; Pierre Garreau; Franck Dumas; Gérald Gregori
Abstract. Model simulations and remote sensing observations show that ocean dynamics at fine scales (1–100 km in space, day–weeks in time) strongly influence the distribution of phytoplankton. However, only few in situ samplings have been performed and most of them in boundary currents which may not be representative of less energetic regions. The PROTEVSMED-SWOT cruise took place in the moderately
-
Novel hydrocarbon-utilizing soil mycobacteria synthesize unique mycocerosic acids at a Sicilian everlasting fire Biogeosciences (IF 3.48) Pub Date : 2021-03-01 Nadine T. Smit; Laura Villanueva; Darci Rush; Fausto Grassa; Caitlyn R. Witkowski; Mira Holzheimer; Adriaan J. Minnaard; Jaap S. Sinninghe Damsté; Stefan Schouten
Soil bacteria rank among the most diverse groups of organisms on Earth and actively impact global processes of carbon cycling, especially in the emission of greenhouse gases like methane, CO2 and higher gaseous hydrocarbons. An abundant group of soil bacteria are the mycobacteria, which colonize various terrestrial, marine and anthropogenic environments due to their impermeable cell envelope that contains
-
Effect of organic carbon addition on paddy soil organic carbon decomposition under different irrigation regimes Biogeosciences (IF 3.48) Pub Date : 2021-03-01 Heleen Deroo; Masuda Akter; Samuel Bodé; Orly Mendoza; Haichao Li; Pascal Boeckx; Steven Sleutel
Abstract. Anaerobic decomposition of organic carbon (OC) in submerged rice paddies is coupled to the reduction of alternative soil electron acceptors, primarily Fe3+. During reductive dissolution of Fe3+ from pedogenic oxides, previously adsorbed native soil organic carbon (SOC) could be co-released into solution. Incorporation of crop residues could hence indirectly, i.e. through the stimulation of
-
Early winter barium excess in the Southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) Biogeosciences (IF 3.48) Pub Date : 2021-03-01 Natasha René van Horsten; Hélène Planquette; Géraldine Sarthou; Thomas James Ryan-Keogh; Thato Nicholas Mtshali; Alakendra Roychoudhury; Eva Bucciarelli
Abstract. The Southern Ocean is of global importance and processes such as mesopelagic remineralisation that impact the efficiency of the biological carbon pump in this region is of substantial interest. During this study the proxy barium excess which is utilised to shed light on mesopelagic remineralisation was measured at seven stations along 30° E in the Southern Indian Ocean during early austral
-
Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements Biogeosciences (IF 3.48) Pub Date : 2021-03-01 Jens Daniel Müller; Bernd Schneider; Ulf Gräwe; Peer Fietzek; Marcus Bo Wallin; Anna Rutgersson; Norbert Wasmund; Siegfried Krüger; Gregor Rehder
Abstract. Organic matter production by cyanobacteria blooms is a major environmental concern for the Baltic Sea as it promotes thespread of anoxic zones. Partial pressure of carbon dioxide (pCO2) measurements carried out on Ships of Opportunity (SOOP) since 2003 have proven to be a powerful tool to resolve the carbon dynamics of the blooms in space and time. However, SOOP measurements lack the possibility
-
Subpollen particles (SPP) of birch as carriers of ice nucleating macromolecules Biogeosciences (IF 3.48) Pub Date : 2021-02-26 Julia Burkart; Jürgen Gratzl; Teresa M. Seifried; Paul Bieber; Hinrich Grothe
Abstract. Within the last years pollen grains have gained increasing attention due to their cloud forming potential. Especially the discovery that ice nucleating macromolecules (INM) or subpollen particles (SPP) obtained from pollen grains are able to initiate freezing has stirred up interest in pollen. INM or SPP are much smaller and potentially more numerous than pollen grains and could significantly
-
Bioturbation has a limited effect on phosphorus burial in salt marsh sediments Biogeosciences (IF 3.48) Pub Date : 2021-02-25 Sebastiaan J. van de Velde; Rebecca K. James; Ine Callebaut; Silvia Hidalgo-Martinez; Filip J. R. Meysman
It has been hypothesized that the evolution of animals during the Ediacaran–Cambrian transition stimulated the burial of phosphorus in marine sediments. This assumption is centrally based on data compilations from marine sediments deposited under oxic and anoxic bottom waters. Since anoxia excludes the presence of infauna and sediment reworking, the observed differences in P burial are assumed to be
-
A modeling study of temporal and spatial pCO2 variability on the biologically active and temperature-dominated Scotian Shelf Biogeosciences (IF 3.48) Pub Date : 2021-02-25 Krysten Rutherford; Katja Fennel; Dariia Atamanchuk; Douglas Wallace; Helmuth Thomas
Abstract. Continental shelves are thought to be affected disproportionately by climate change and are a large contributor to global air-sea carbon dioxide (CO2) fluxes. It is often reported that low-latitude shelves tend to act as net sources of CO2 whereas mid- and high-latitude shelves act as net sinks. Here, we combine a high-resolution regional model with surface water time-series and repeat transect
-
Spatio-temporal variations in lateral and atmospheric carbon fluxes from the Danube Delta Biogeosciences (IF 3.48) Pub Date : 2021-02-24 Marie-Sophie Maier; Cristian R. Teodoru; Bernhard Wehrli
River deltas, with their mosaic of ponds, channels and seasonally inundated areas, act as the last continental hot spots of carbon turnover along the land–ocean aquatic continuum. There is increasing evidence for the important role of riparian wetlands in the transformation and emission of terrestrial carbon to the atmosphere. The considerable spatial heterogeneity of river deltas, however, forms a
-
Physiological responses of Skeletonema costatum to the interactions of seawater acidification and the combination of photoperiod and temperature Biogeosciences (IF 3.48) Pub Date : 2021-02-24 Hangxiao Li; Tianpeng Xu; Jing Ma; Futian Li; Juntian Xu
Ocean acidification (OA), which is a major environmental change caused by increasing atmospheric CO2, has considerable influences on marine phytoplankton. But few studies have investigated interactions of OA and seasonal changes in temperature and photoperiod on marine diatoms. In the present study, a marine diatom Skeletonema costatum was cultured under two different CO2 levels (LC, 400 µatm; HC,
-
Technical note: Interpreting pH changes Biogeosciences (IF 3.48) Pub Date : 2021-02-24 Andrea J. Fassbender; James C. Orr; Andrew G. Dickson
The number and quality of ocean pH measurements have increased substantially over the past few decades such that trends, variability, and spatial patterns of change are now being evaluated. However, comparing pH changes across domains with different initial pH values can be misleading because a pH change reflects a relative change in the hydrogen ion concentration ([H+], expressed in mol kg−1) rather
-
A novel representation of biological nitrogen fixation and competitive dynamics between nitrogen-fixing and non-fixing plants in a land model (GFDL LM4.1-BNF) Biogeosciences (IF 3.48) Pub Date : 2021-02-24 Sian Kou-Giesbrecht; Sergey Malyshev; Isabel Martínez Cano; Stephen W. Pacala; Elena Shevliakova; Thomas A. Bytnerowicz; Duncan N. L. Menge
Abstract. Representing biological nitrogen fixation (BNF) is an important challenge in the incorporation of nitrogen (N) cycling in land models. Initial representations of BNF in land models applied simplified phenomenological relationships. More recent representations of BNF are mechanistic and include the dynamic response of BNF to N limitation of plant growth. However, they generally do not include
-
Intraseasonal variability of greenhouse gas emission factors from biomass burning in the Brazilian Cerrado Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Roland Vernooij; Marcos Giongo; Marco Assis Borges; Máximo Menezes Costa; Ana Carolina Sena Barradas; Guido R. van der Werf
Landscape fires, often referred to as biomass burning (BB), emit substantial amounts of (greenhouse) gases and aerosols into the atmosphere each year. Frequently burning savannas, mostly in Africa, Australia, and South America are responsible for over 60 % of total BB carbon emissions. Compared to many other sources of emissions, fires have a strong seasonality. Previous research has identified the
-
Technical note: Seamless gas measurements across the land–ocean aquatic continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environments Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Anna Rose Canning; Peer Fietzek; Gregor Rehder; Arne Körtzinger
The ocean and inland waters are two separate regimes, with concentrations in greenhouse gases differing on orders of magnitude between them. Together, they create the land–ocean aquatic continuum (LOAC), which comprises itself largely of areas with little to no data with regards to understanding the global carbon system. Reasons for this include remote and inaccessible sample locations, often tedious
-
The effect of the salinity, light regime and food source on carbon and nitrogen uptake in a benthic foraminifer Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Michael Lintner; Bianca Lintner; Wolfgang Wanek; Nina Keul; Petra Heinz
Foraminifera are unicellular organisms that play an important role in marine organic matter cycles. Some species are able to isolate chloroplasts from their algal food source and incorporate them as kleptoplasts into their own metabolic pathways, a phenomenon known as kleptoplastidy. One species showing this ability is Elphidium excavatum, a common foraminifer in the Kiel Fjord, Germany. The Kiel Fjord
-
Influence of land use and occupation on the water quality of a microbasin in the southwestern Amazon Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Alan Gomes Mendonça; Josilena de Jesus Laureano; Daíse da Silva Lopes; Lindolaine Machado de Sousa; Tiago de Oliveira Lima; Ana Lúcia Denardin da Rosa; Beatriz Machado Gomes; Igor David da Costa; Elisabete Lourdes do Nascimento
Abstract. Water resource management in Brazil is constantly evolving, and greater knowledge about this resource allows better planning and more sustainable uses. In Brazil, the improvement of water resource management faces the difficulty of implementing the instruments of the National Water Resources Policy, such as classification of water bodies. Thus, to help improve the water management instruments
-
Tritium activity concentration and behaviour in coastal regions of Fukushima in 2014 Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Michio Aoyama; Sabine Charmasson; Yasunori Hamajima; Celine Duffa; Daisuke Tsumune; Yutaka Tateda
Abstract. We observed 3H activity concentrations and the 137Cs activity concentrations during the SoSo 5 rivers cruise in 2014 and at the Tomioka port in 2014–2018. The 3H activity concentrations at coastal stations located close to the Fukushima coast ranged from 90 Bq m−3 to 175 Bq m−3, and decreased between 67 Bq m−3 to 83 Bq m−3 at the stations located 12–16 km from the coast. The 3H activity concentration
-
Temporal patterns and biophysical controls on methane emissions from a small eutrophic reservoir: insights from two years of eddy covariance monitoring Biogeosciences (IF 3.48) Pub Date : 2021-02-23 Sarah Waldo; Jake J. Beaulieu; William Barnett; David A. Balz; Michael J. Vanni; Tanner Williamson; John T. Walker
Abstract. Waters impounded behind dams (i.e. reservoirs) are important sources of greenhouses gases, especially methane (CH4), but their contribution is not well constrained due to high spatial and temporal variability, limitations in monitoring methods to characterize hot spot and hot moment emissions, and the limited number of studies that investigate diurnal, seasonal, and interannual patterns in
-
Slow-down of the greening trend in natural vegetation with further rise in atmospheric CO2 Biogeosciences (IF 3.48) Pub Date : 2021-02-23 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; Victor Brovkin
Abstract. Satellite data reveal widespread changes of Earth's vegetation cover. Regions intensively attended to by humans are mostly greening due to land management. Natural vegetation, on the other hand, is exhibiting patterns of both greening and browning in all continents. Factors linked to anthropogenic carbon emissions, such as CO2 fertilization, climate change and consequent disturbances, such
-
Changes in population depth distribution and oxygen stratification are involved in the current low condition of the eastern Baltic Sea cod (Gadus morhua) Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Michele Casini; Martin Hansson; Alessandro Orio; Karin Limburg
During the past 20 years, hypoxic areas have expanded rapidly in the Baltic Sea, which has become one of the largest marine “dead zones” in the world. At the same time, the most important commercial fish population of the region, the eastern Baltic cod, has experienced a drastic reduction in mean body condition, but the processes behind the relation between deoxygenation and condition remain elusive
-
Changing sources and processes sustaining surface CO2 and CH4 fluxes along a tropical river to reservoir system Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Cynthia Soued; Yves T. Prairie
Freshwaters are important emitters of carbon dioxide (CO2) and methane (CH4), two potent greenhouse gases (GHGs). While aquatic surface GHG fluxes have been extensively measured, there is much less information about their underlying sources. In lakes and reservoirs, surface GHG can originate from horizontal riverine flow, the hypolimnion, littoral sediments, and water column metabolism. These sources
-
Anthropogenic CO2-mediated freshwater acidification limits survival, calcification, metabolism, and behaviour in stress-tolerant freshwater crustaceans Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Alex R. Quijada-Rodriguez; Pou-Long Kuan; Po-Hsuan Sung; Mao-Ting Hsu; Garett J. P. Allen; Pung Pung Hwang; Yung-Che Tseng; Dirk Weihrauch
Abstract. Dissolution of anthropogenic CO2 is chronically acidifying aquatic ecosystems. Studies indicate that ocean acidification will cause marine life, especially calcifying species, to suffer at the organismal and ecosystem levels. In comparison, freshwater acidification has received less attention rendering its consequences unclear. Here, juvenile Chinese mitten crabs, Eriocheir sinensis, were
-
Response of tropical marine benthic diatoms exposed to elevated irradiance and temperature Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Sazlina Salleh; Andrew McMinn
Abstract. Shallow tropical marine environments are likely to experience future water temperatures that will challenge the ability of life to survive. Changes in temperature and irradiance during tidal cycles in the Tanjung Rhu estuary, Langkawi, Malaysia in 2007 did not significantly affect the benthic diatom communities, although, higher photosynthetic parameters, such as maximum relative electron
-
Sediment and carbon accumulation in a glacial lake in Chukotka (Arctic Siberia) during the late Pleistocene and Holocene: Combining hydroacoustic profiling and down-core analyses Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Stuart A. Vyse; Ulrike Herzschuh; Gregor Pfalz; Lyudmila A. Pestryakova; Bernhard Diekmann; Norbert Nowaczyk; Boris K. Biskaborn
Abstract. Lakes act as important sinks for inorganic and organic sediment components. However, investigations of sedimentary carbon budgets within glacial lakes are currently absent from Arctic Siberia. The aim of this paper is to provide the first reconstruction of accumulation rates, sediment and carbon budgets from a lacustrine sediment core from Lake Rauchuagytgyn, Chukotka (Arctic Siberia). We
-
Drought effects on leaf fall, leaf flushing and stem growth in Neotropical forest; reconciling remote sensing data and field observations Biogeosciences (IF 3.48) Pub Date : 2021-02-22 Thomas Janssen; Ype van der Velde; Florian Hofhansl; Sebastiaan Luyssaert; Kim Naudts; Bart Driessen; Katrin Fleischer; Han Dolman
Abstract. Large amounts of carbon flow through tropical ecosystems every year, from which a part is sequestered in biomass through tree growth. However, the effects of ongoing warming and drying on tree growth and carbon sequestration in tropical forest is still highly uncertain. Field observations are sparse and limited to a few sites while remote sensing analysis shows diverging growth responses
-
Role of jellyfish in the plankton ecosystem revealed using a global ocean biogeochemical model Biogeosciences (IF 3.48) Pub Date : 2021-02-18 Rebecca M. Wright; Corinne Le Quéré; Erik Buitenhuis; Sophie Pitois; Mark J. Gibbons
Jellyfish are increasingly recognised as important components of the marine ecosystem, yet their specific role is poorly defined compared to that of other zooplankton groups. This paper presents the first global ocean biogeochemical model that includes an explicit representation of jellyfish and uses the model to gain insight into the influence of jellyfish on the plankton community. The Plankton Type
-
Reviews and syntheses: The biogeochemical cycle of silicon in the modern ocean Biogeosciences (IF 3.48) Pub Date : 2021-02-18 Paul J. Tréguer; Jill N. Sutton; Mark Brzezinski; Matthew A. Charette; Timothy Devries; Stephanie Dutkiewicz; Claudia Ehlert; Jon Hawkings; Aude Leynaert; Su Mei Liu; Natalia Llopis Monferrer; María López-Acosta; Manuel Maldonado; Shaily Rahman; Lihua Ran; Olivier Rouxel
The element silicon (Si) is required for the growth of silicified organisms in marine environments, such as diatoms. These organisms consume vast amounts of Si together with N, P, and C, connecting the biogeochemical cycles of these elements. Thus, understanding the Si cycle in the ocean is critical for understanding wider issues such as carbon sequestration by the ocean's biological pump. In this
-
Reviews and syntheses: Impacts of plant-silica–herbivore interactions on terrestrial biogeochemical cycling Biogeosciences (IF 3.48) Pub Date : 2021-02-17 Bernice C. Hwang; Daniel B. Metcalfe
Researchers have known for decades that silicon plays a major role in biogeochemical and plant–soil processes in terrestrial systems. Meanwhile, plant biologists continue to uncover a growing list of benefits derived from silicon to combat abiotic and biotic stresses, such as defense against herbivory. Yet despite growing recognition of herbivores as important ecosystem engineers, many major gaps remain
-
Blue Carbon Stocks and Exchanges Along the Pacific West Coast Biogeosciences (IF 3.48) Pub Date : 2021-02-17 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; Kathryn M. Beheshti
Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon
-
Evaluating the Arabian Sea as a regional source of atmospheric CO2: seasonal variability and drivers Biogeosciences (IF 3.48) Pub Date : 2021-02-17 Alain de Verneil; Zouhair Lachkar; Shafer Smith; Marina Lévy
Abstract. The Arabian Sea (AS) was confirmed to be a net emitter of CO2 to the atmosphere during the international Joint Global Ocean Flux Study program of the 1990s, but since then little in situ data has been collected, leaving data-based methods to calculate air-sea exchange with fewer data and potentially out-of-date. Additionally, coarse-resolution models underestimate CO2 flux compared to other
-
Haplo-diplontic life cycle expands coccolithophore niche Biogeosciences (IF 3.48) Pub Date : 2021-02-16 Joost de Vries; Fanny Monteiro; Glen Wheeler; Alex Poulton; Jelena Godrijan; Federica Cerino; Elisa Malinverno; Gerald Langer; Colin Brownlee
Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases and potentially expands coccolithophore niche volume. Research has, however, to date largely overlooked the life cycle of coccolithophores and has instead focused on the diploid life cycle phase
-
Age distribution, extractability, and stability of mineral-bound organic carbon in central European soils Biogeosciences (IF 3.48) Pub Date : 2021-02-16 Marion Schrumpf; Klaus Kaiser; Allegra Mayer; Günter Hempel; Susan Trumbore
The largest share of total soil organic carbon (OC) is associated with minerals. However, the factors that determine the amount and turnover of slower- versus faster-cycling components of mineral-associated carbon (MOC) are still poorly understood. Bioavailability of MOC is thought to be regulated by desorption, which can be facilitated by displacement and mobilization by competing ions. However, MOC
-
Denitrification in soil as a function of oxygen availability at the microscale Biogeosciences (IF 3.48) Pub Date : 2021-02-16 Lena Rohe; Bernd Apelt; Hans-Jörg Vogel; Reinhard Well; Gi-Mick Wu; Steffen Schlüter
The prediction of nitrous oxide (N2O) and of dinitrogen (N2) emissions formed by biotic denitrification in soil is notoriously difficult due to challenges in capturing co-occurring processes at microscopic scales. N2O production and reduction depend on the spatial extent of anoxic conditions in soil, which in turn are a function of oxygen (O2) supply through diffusion and O2 demand by respiration in
-
Evaluating stream CO2 outgassing via drifting and anchored flux chambers in a controlled flume experiment Biogeosciences (IF 3.48) Pub Date : 2021-02-16 Filippo Vingiani; Nicola Durighetto; Marcus Klaus; Jakob Schelker; Thierry Labasque; Gianluca Botter
Carbon dioxide (CO2) emissions from running waters represent a key component of the global carbon cycle. However, quantifying CO2 fluxes across air–water boundaries remains challenging due to practical difficulties in the estimation of reach-scale standardized gas exchange velocities (k600) and water equilibrium concentrations. Whereas craft-made floating chambers supplied by internal CO2 sensors represent
-
The seasonal phases of an Arctic lagoon reveal the discontinuities of pH variability and CO2 flux at the air–sea interface Biogeosciences (IF 3.48) Pub Date : 2021-02-16 Cale A. Miller; Christina Bonsell; Nathan D. McTigue; Amanda L. Kelley
The western Arctic Ocean, including its shelves and coastal habitats, has become a focus in ocean acidification research over the past decade as the colder waters of the region and the reduction of sea ice appear to promote the uptake of excess atmospheric CO2. Due to seasonal sea ice coverage, high-frequency monitoring of pH or other carbonate chemistry parameters is typically limited to infrequent
-
The northern European shelf as an increasing net sink for CO2 Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Meike Becker; Are Olsen; Peter Landschützer; Abdirhaman Omar; Gregor Rehder; Christian Rödenbeck; Ingunn Skjelvan
We developed a simple method to refine existing open-ocean maps and extend them towards different coastal seas. Using a multi-linear regression we produced monthly maps of surface ocean fCO2 in the northern European coastal seas (the North Sea, the Baltic Sea, the Norwegian Coast and the Barents Sea) covering a time period from 1998 to 2016. A comparison with gridded Surface Ocean CO2 Atlas (SOCAT)
-
Biotic and abiotic transformation of amino acids in cloud water: experimental studies and atmospheric implications Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Saly Jaber; Muriel Joly; Maxence Brissy; Martin Leremboure; Amina Khaled; Barbara Ervens; Anne-Marie Delort
The interest in organic nitrogen and particularly in quantifying and studying the fate of amino acids (AAs) has been growing in the atmospheric-science community. However very little is known about biotic and abiotic transformation mechanisms of amino acids in clouds.In this work, we measured the biotransformation rates of 18 amino acids with four bacterial strains (Pseudomonas graminis PDD-13b-3,
-
The transformation of the forest steppe in the lower Danube Plain of southeastern Europe: 6000 years of vegetation and land use dynamics Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Angelica Feurdean; Roxana Grindean; Gabriela Florescu; Ioan Tanţău; Eva M. Niedermeyer; Andrei-Cosmin Diaconu; Simon M. Hutchinson; Anne Brigitte Nielsen; Tiberiu Sava; Andrei Panait; Mihaly Braun; Thomas Hickler
Abstract. Forest steppes are dynamic ecosystems, highly susceptible to changes in climate, disturbances and land use. Here we examine the Holocene history of the European forest steppe ecotone in the lower Danube Plain to better understand its sensitivity to climate fluctuations, fire and human impact, and the timing of its transition into a cultural forest steppe. We used multi-proxy analyses (pollen
-
Alkenone isotopes show evidence of active carbon concentrating mechanisms in coccolithophores as aqueous carbon dioxide concentrations fall below 7 µmol L−1 Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Marcus P. S. Badger
Coccolithophores and other haptophyte algae acquire the carbon required for metabolic processes from the water in which they live. Whether carbon is actively moved across the cell membrane via a carbon concentrating mechanism, or passively through diffusion, is important for haptophyte biochemistry. The possible utilization of carbon concentrating mechanisms also has the potential to over-print one
-
Key drivers of pyrogenic carbon redistribution during a simulated rainfall event Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Severin-Luca Bellè; Asmeret Asefaw Berhe; Frank Hagedorn; Cristina Santin; Marcus Schiedung; Ilja van Meerveld; Samuel Abiven
Pyrogenic carbon (PyC) is produced by the incomplete combustion of vegetation during wildfires and is a major and persistent pool of the global carbon (C) cycle. However, its redistribution in the landscape after fires remains largely unknown. Therefore, we conducted rainfall simulation experiments on 0.25 m2 plots with two distinct Swiss forest soils (Cambisol (clay loam) and Luvisol (sandy silt))
-
Temporal dynamics of tree xylem water isotopes: In-situ monitoring and modelling Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Stefan Seeger; Markus Weiler
Abstract. We developed a setup for a fully automated, high frequency in-situ monitoring system of the stable water isotopes Deuterium and 18O in soil water and tree xylem. The setup was tested for 12 weeks within an isotopic labelling experiment during a large artificial sprinkling experiment including three mature European beech (Fagus sylvatica) trees. Our setup allowed for one measurement every
-
Weekly reconstruction of pH and total alkalinity in an upwelling-dominated coastal ecosystem through neural networks (ATpH-NN): The case of Ría de Vigo (NW Spain) between 1992 and 2019 Biogeosciences (IF 3.48) Pub Date : 2021-02-15 Daniel Broullón; Fiz F. Pérez; María Dolores Doval
Abstract. Short and long-term variability of seawater carbon dioxide (CO2) system shows large differences between different ecosystems which are derived from the characteristic processes of each area. The high variability of coastal ecosystems, their ecological and economic significance, the anthropogenic influence on them and their behavior as sources or sinks of atmospheric CO2, highlight the relevance
-
Impacts of biogenic polyunsaturated aldehydes on metabolism and community composition of particle-attached bacteria in coastal hypoxia Biogeosciences (IF 3.48) Pub Date : 2021-02-12 Zhengchao Wu; Qian P. Li; Zaiming Ge; Bangqin Huang; Chunming Dong
Eutrophication-driven coastal hypoxia has been of great interest for decades, though its mechanisms remain not fully understood. Here, we showed elevated concentrations of particulate and dissolved polyunsaturated aldehydes (PUAs) associated with the hypoxic waters in the bottom layer of a salt-wedge estuary. Bacterial respiration within the hypoxic waters was mainly contributed by particle-attached
-
Incorporating the stable carbon isotope 13C in the ocean biogeochemical component of the Max Planck Institute Earth System Model Biogeosciences (IF 3.48) Pub Date : 2021-02-12 Bo Liu; Katharina D. Six; Tatiana Ilyina
Abstract. Direct comparison between paleo oceanic δ13C records and model results facilitates assessing simulated distributions and properties of water masses in the past. To accomplish this, we include a new representation of the stable carbon isotope 13C into the HAMburg Ocean Carbon Cycle model (HAMOCC), the ocean biogeochemical component of the Max Planck Institute Earth System Model (MPI-ESM).
-
Retracing Hypoxia in Eckernförde Bight (Baltic Sea) Biogeosciences (IF 3.48) Pub Date : 2021-02-12 Heiner Dietze; Ulrike Löptien
Abstract. In recent years, upwelling events of low-oxygenated deep water have been repeatedly observed in Eckernförde Bight (EB) situated in the Baltic Sea, Germany. Many of these events were related to massive fish-kill incidents – with negative consequences for commercial fisheries and tourism. The aim of this study is to dissect underlying mechanisms and to explore the potential of existing monitoring
-
Sedimentation rate and organic matter dynamics shape microbiomes across a continental margin Biogeosciences (IF 3.48) Pub Date : 2021-02-12 Sabyasachi Bhattacharya; Tarunendu Mapder; Svetlana Fernandes; Chayan Roy; Jagannath Sarkar; Moidu Jameela Rameez; Subhrangshu Mandal; Abhijit Sar; Amit Kumar Chakraborty; Nibendu Mondal; Sumit Chatterjee; Bomba Dam; Aditya Peketi; Ranadhir Chakraborty; Aninda Mazumdar; Wriddhiman Ghosh
Abstract. Marine sedimentation rate and bottom-water O2 concentration control the remineralization/sequestration of organic carbon across continental margins; but whether/how they shape microbiome architecture (the ultimate effector of all biogeochemical phenomena), across shelf/slope sediments, is unknown. Here we reveal distinct microbiome structures and functions, amidst comparable pore fluid chemistries
-
Subsurface flow and phosphorus dynamics in beech forest hillslopes during sprinkling experiments: how fast is phosphorus replenished? Biogeosciences (IF 3.48) Pub Date : 2021-02-11 Michael Rinderer; Jaane Krüger; Friederike Lang; Heike Puhlmann; Markus Weiler
The phosphorus (P) concentration of soil solution is of key importance for plant nutrition. During large rainfall events, the P concentration is altered by lateral and vertical subsurface storm flow (SSF) that facilitates P mobilization, redistribution within the soil profile and potential P export from the ecosystem. These processes are not well studied under field conditions. Important factors of
-
The climate benefit of carbon sequestration Biogeosciences (IF 3.48) Pub Date : 2021-02-11 Carlos A. Sierra; Susan E. Crow; Martin Heimann; Holger Metzler; Ernst-Detlef Schulze
Ecosystems play a fundamental role in climate change mitigation by photosynthetically fixing carbon from the atmosphere and storing it for a period of time in organic matter. Although climate impacts of carbon emissions by sources can be quantified by global warming potentials, the appropriate formal metrics to assess climate benefits of carbon removals by sinks are unclear. We introduce here the climate
-
Methane efflux from an American bison herd Biogeosciences (IF 3.48) Pub Date : 2021-02-10 Paul C. Stoy; Adam A. Cook; John E. Dore; Natascha Kljun; William Kleindl; E. N. Jack Brookshire; Tobias Gerken
American bison (Bison bison L.) have recovered from the brink of extinction over the past century. Bison reintroduction creates multiple environmental benefits, but impacts on greenhouse gas emissions are poorly understood. Bison are thought to have produced some 2 Tg yr−1 of the estimated 9–15 Tg yr−1 of pre-industrial enteric methane emissions, but few measurements have been made due to their mobile
-
Vertical distribution of planktic foraminifera through an oxygen minimum zone: how assemblages and test morphology reflect oxygen concentrations Biogeosciences (IF 3.48) Pub Date : 2021-02-10 Catherine V. Davis; Karen Wishner; Willem Renema; Pincelli M. Hull
Oxygen-depleted regions of the global ocean are rapidly expanding, with important implications for global biogeochemical cycles. However, our ability to make projections about the future of oxygen in the ocean is limited by a lack of empirical data with which to test and constrain the behavior of global climatic and oceanographic models. We use depth-stratified plankton tows to demonstrate that some
-
The composition of endolithic communities in gypcrete is determined by the specific microhabitat architecture Biogeosciences (IF 3.48) Pub Date : 2021-02-10 María Cristina Casero; Victoria Meslier; Jocelyne DiRuggiero; Antonio Quesada; Carmen Ascaso; Octavio Artieda; Tomasz Kowaluk; Jacek Wierzchos
Endolithic microhabitats have been described as the last refuge for life in arid and hyper-arid deserts where life has to deal with harsh environmental conditions. A number of rock substrates from the hyper-arid Atacama Desert, colonized by endolithic microbial communities such as halite, gypsum crusts, gypcrete, calcite, granite and ignimbrite, have been characterized and compared using different
Contents have been reproduced by permission of the publishers.