Article
Environmental Sciences
Britta M. Voss, Timothy Eglinton, Bernhard Peucker-Ehrenbrink, Valier Galy, Susan Q. Lang, Cameron McIntyre, Robert G. M. Spencer, Ekaterina Bulygina, Zhaohui Aleck Wang, Katherine A. Guay
Summary: The sources of carbon in the Fraser River system vary spatially and temporally. Tributaries in the northern interior consistently contribute higher concentrations of dissolved organic carbon (DOC) to the main stem. The radiocarbon age of DOC exported from the Fraser River does not change significantly across seasons, indicating that there is modulation of heterogeneous chemical and isotopic signals during transit through the river basin. Dissolved inorganic carbon (DIC) concentrations are highest in the Rocky Mountain headwater region and in tributaries with high DOC concentrations, suggesting that DOC respiration plays a significant role in DIC in this basin. Overall, the cycling of DOC and DIC is closely linked in the river network, with active processing and transformation of carbon during transport.
Article
Multidisciplinary Sciences
Timothy Eglinton, Valier V. Galy, Jordon D. Hemingway, Xiaojuan Feng, Hongyan Bao, Thomas M. Blattmann, Angela F. Dickens, Hannah Gies, Liviu Giosan, Negar Haghipour, Pengfei Hou, Maarten Lupker, Cameron P. McIntyre, Daniel B. Montlucon, Bernhard Peucker-Ehrenbrink, Camilo Ponton, Enno Schefuss, Melissa S. Schwab, Britta M. Voss, Lukas Wacker, Ying Wu, Meixun Zhao
Summary: Terrestrial vegetation and soils hold significantly more carbon than the atmosphere. Human activities impacting these reserves may exacerbate climate change uncertainties, particularly in extrapolating point-source observations to ecosystem-scale budgets. The turnover of organic carbon in river basins is influenced by mean annual temperature and precipitation, with implications for soil organic carbon vulnerability on a global scale. The scaling of riverine biospheric-carbon ages with soil OC turnover reveals the potential for constraints on carbon dynamics across broad spatial scales.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geosciences, Multidisciplinary
Yeongjin Ryu, Heejun Han, Taehee Na, Guebuem Kim, Ellen R. M. Druffel, Jeomshik Hwang
Summary: The East Sea, connected to the Northwest Pacific, is a miniature ocean with independent deep water circulation. The radiocarbon age of dissolved organic carbon (DOC) in the East Sea is older than its water turnover time, indicating the transportation of aged DOC from the Northwest Pacific. The oldest DOC is found in the subsurface layer and is a mixture of old DOC from the North Pacific and modern DOC produced in the East Sea. These findings provide insights into the global cycling of DOC in the surface ocean.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Green & Sustainable Science & Technology
Li Zhou, Timothy J. Tse, Farley Chicilo, Jianheng Shen, Venkatesh Meda, Martin J. T. Reaney
Summary: In this study, electrostatic field (E-field) and nano-adsorbents were used to refine crude fatty acid methyl ester (FAME). The results showed a significant reduction in soap content and successful removal of spent nano-adsorbents using E-field treatment, with minimal FAME loss. The combination of E-field and nano-adsorbents offers distinct advantages for FAME refining.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Environmental Sciences
Blanca Ausin, Gina Bossert, Nicola Krake, Sarah Paradis, Negar Haghipour, Xavier Durrieu de Madron, Belen Alonso, Timothy Eglinton
Summary: This study investigates the origin and fate of organic matter in marine sediments in the Western Mediterranean Sea and adjacent Atlantic Ocean sector. The results reveal a southwest to northeast gradient in geographical and sedimentological features. Changes in primary productivity, river discharge, and canyons are identified as factors influencing the spatial distribution of organic carbon. Additionally, the study suggests the influence of lateral transport of allochthonous organic carbon and selective degradation of labile organic matter, as well as the protection of organic matter through association with mineral surfaces.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Megan I. Behnke, Jason B. Fellman, Sonia Nagorski, Robert G. M. Spencer, Eran Hood
Summary: This research examines the impact of glacierization on the source and contribution of particulate organic carbon (POC) in Southeast Alaska. The study finds that glacier melting releases more rock petrogenic POC, while non-glacier areas primarily flush POC through rainfall. However, glacier rivers still play a significant role in POC export, especially in heavily glacierized regions. Additionally, glacier retreat can lead to a decrease in carbon storage and create a positive feedback mechanism to climate change.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Shuai Chen, Jun Zhong, Siliang Li, Lishan Ran, Wanfa Wang, Sen Xu, Zelong Yan, Sheng Xu
Summary: Riverine transport of carbon from the land to the oceans is significant in the global carbon cycle. The study in southwest China shows that carbon dynamics in subtropical rivers are highly affected by aquatic photosynthesis, which has significant implications on carbon cycling within river systems.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Hongmei Zhang, Fuqiang Wang, Sen Shan, Peng Ren, Chunle Luo, Wenjing Fu, Shuwen Sun, Xuchen Wang
Summary: This study investigated the concentrations and carbon isotope compositions of dissolved organic and inorganic carbon in Qinghai Lake and its inflowing rivers on the northeastern Qinghai-Tibetan Plateau of China. The results revealed differences in concentrations and isotopic compositions between the lake and rivers, as well as differences in the concentrations of major ions. Chemical weathering of rocks and biological processes played important roles in controlling the distribution of carbon and ions in the rivers and lake.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Multidisciplinary Sciences
Julia Steinbach, Henry Holmstrand, Kseniia Shcherbakova, Denis Kosmach, Volker Bruchert, Natalia Shakhova, Anatoly Salyuk, Celia J. Sapart, Denis Chernykh, Riko Noormets, Igor Semiletov, Orjan Gustafsson
Summary: The study investigates the sources of methane release in the East Siberian Arctic Shelf, indicating a significant contribution from submerged carbon and methane. Methane concentrations in the Laptev Sea showed large fluctuations and isotopic composition suggested a thermogenic/natural gas source in two seepage areas, with methane oxidation occurring further from the seeps. This knowledge is crucial for predicting future methane emissions in the region.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Qingyuan Zhang, Utkarsh Sharma, Jordan A. Dennis, Andrea Scifo, Margot Kuitems, Ulf Buentgen, Mathew J. Owens, Michael W. Dee, Benjamin J. S. Pope
Summary: Annually resolved measurements of tree-ring radiocarbon content have revealed rare sharp rises, called 'Miyake events', which are likely caused by rare increases in cosmic radiation. These events challenge existing astrophysical or geophysical models, and analyzing them requires modeling the global carbon cycle. In this study, the researchers introduce an open-source Python package called 'ticktack' that connects box models of carbon cycle with Bayesian inference tools. Using this package, they analyze all public annual 14C tree data and infer posterior parameters for the six known Miyake events.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Ellen R. M. Druffel, Sheila Griffin, Christian B. Lewis, Megha Rudresh, Noreen G. Garcia, Robert M. Key, Ann P. McNichol, Niels E. Hauksson, Brett D. Walker
Summary: The study found that marine dissolved organic carbon concentrations in the Southern Ocean and eastern Pacific are primarily controlled by the transport of deep waters northward. Low DOC increment C-14 and delta C-13 measurements at specific depths may indicate a source of DOC from nearby hydrothermal ridge systems.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Peter Kohler, Florian Adolphi, Martin Butzin, Raimund Muscheler
Summary: This article discusses the challenges in combining changes in C-14 production rate (Q) and carbon cycle to explain the reconstructed atmospheric Delta C-14 record, and analyzes possible reasons for this difficulty. Hypothetical Q values are derived using two different models and compared with data-based estimates. The results indicate a deficit in the current data-based approaches.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2022)
Article
Biodiversity Conservation
Katherine Heckman, Caitlin E. Hicks Pries, Corey R. Lawrence, Craig Rasmussen, Susan E. Crow, Alison M. Hoyt, Sophie F. von Fromm, Zheng Shi, Shane Stoner, Casey McGrath, Jeffrey Beem-Miller, Asmeret Asefaw Berhe, Joseph C. Blankinship, Marco Keiluweit, Erika Marin-Spiotta, J. Grey Monroe, Alain F. Plante, Joshua Schimel, Carlos A. Sierra, Aaron Thompson, Rota Wagai
Summary: Understanding the factors controlling soil organic carbon (C) amount and persistence is crucial for predicting its sensitivity to global change. Different pools of soil organic C show varying degrees of persistence and relationships with environmental factors, with soil depth being the best predictor of C abundance and persistence. Climate, particularly temperature and wetness index, plays a significant role in determining soil C properties and potential loss from protected pools.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Yuhao Dai, Jimin Yu, Patrick Rafter
Summary: The study reveals changes in the carbon storage in the deep Southern Ocean during specific periods of the Last Glacial Maximum, highlighting the impacts of sea-ice and stratification between Upper and Lower Circumpolar Deep Waters.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Environmental Sciences
Sen Shan, Chunle Luo, Yuanzhi Qi, Wei-Jun Cai, Shuwen Sun, Di Fan, Xuchen Wang
Summary: Transport of terrigenous carbon by rivers in China has been significantly impacted by climate change and human activities in recent decades. Different rivers in China show variations in DIC concentrations and ages, with chemical weathering playing an important role in controlling the production and fate of DIC. Carbonate rock weathering contributes significantly to riverine DIC in the Yangtze River, while silicate rock weathering dominates in the Yellow, Pearl, and Heilongjiang rivers.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)
Article
Soil Science
Katharina Stolze, Andrew D. Barnes, Nico Eisenhauer, Kai U. Totsche
Summary: This study investigates the linkage between earthworms, roots, and soil properties with the number of biopores. It reveals complex relationships among roots, earthworms, biopores, and soil properties, with land-use intensity playing a significant role. The occurrence, frequency, and persistence of biopores are found to be influenced by these interdependencies.
Article
Engineering, Environmental
Christian Zerfass, Robert Lehmann, Nico Ueberschaar, Carlos Sanchez-Arcos, Kai Uwe Totsche, Georg Pohnert
Summary: Understanding the composition, transport and evolution of dissolved organic matter in groundwater is crucial for its protection and sustainable use. Groundwater metabolomics provides valuable insights into the response of groundwater ecosystems to external impacts and the effects of recharge dynamics.
Article
Microbiology
Rebecca E. Cooper, Jessica Finck, Clara Chan, Kirsten Kuesel
Summary: The genome of iron-oxidizing bacterium Sideroxydans sp. CL21 contains additional metabolic traits to adapt to its unique habitat, and it grows by simultaneously using substrate combinations. Sideroxydans sp. CL21 is a microaerobic, acid-tolerant Fe(II)-oxidizer, isolated from the Schloppnerbrunnen fen. The larger genome size of strain CL21 compared to strain ES-1 suggests the presence of additional metabolic traits for survival in the fen.
FEMS MICROBIOLOGY ECOLOGY
(2023)
Article
Environmental Sciences
Thomas Ritschel, Kai Uwe Totsche
Summary: Soil biogeochemistry is interconnected with the redox cycling of iron and manganese, where manganese oxides serve as electron acceptors and might be reduced by organic substances as electron donors. In this study, we investigated the impact of low-molecular-weight organic acids (LMWOA) on the transformation of birnessite. Our findings suggest that the reductive transformation of birnessite into more stable forms of manganese oxides is facilitated by the oxidation of LMWOA, which serves as electron donors. This process plays a critical role in controlling the abundance of LMWOA in natural systems.
Article
Biodiversity Conservation
Markus Lange, Nico Eisenhauer, Hongmei Chen, Gerd Gleixner
Summary: Soils play a crucial role in ecosystem functioning and service provisioning. Plant diversity has positive effects on soil organic matter, but most studies have focused on topsoil and long-term studies are limited. This study investigated the impacts of plant diversity on soil carbon and nitrogen concentrations and stocks, and found that higher plant diversity increased carbon and nitrogen storage, particularly in the topsoil. The effects of plant diversity on soil organic matter became stronger over time and extended to subsoil layers.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Biodiversity Conservation
Mario Reichenbach, Peter Fiener, Alison Hoyt, Susan Trumbore, Johan Six, Sebastian Doetterl
Summary: Soil organic carbon (SOC) dynamics in deeply weathered tropical soils are not well understood. In this study, we compared SOC stocks and turnover in montane tropical forest and cropland. We found that land use did not significantly alter SOC, but differences in SOC could be explained by soil physicochemical properties. Labile organo-mineral associations and exchangeable base cations were identified as the main controls over SOC stocks and turnover. Our findings suggest that increasing C inputs in deeply weathered soils may not lead to long-term SOC stabilization.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Plant Sciences
Natalie J. Oram, Johannes Ingrisch, Richard D. Bardgett, Fiona Brennan, Georg Dittmann, Gerd Gleixner, Paul Illmer, Nadine Praeg, Michael Bahn
Summary: Grasslands face increasing drought intensity, but their response to it is unclear. This study investigated the effects of drought intensity on plant productivity, plant-soil carbon and nitrogen cycling. The results showed that slow-strategy plant communities were more drought resistant and had higher productivity thresholds compared to fast-strategy communities. Increasing past drought intensity resulted in greater microbial uptake of recent plant-assimilated carbon and increased soil nitrogen availability. The recovery responses of plant communities varied depending on their strategies, with the fast-strategy community exhibiting greater compensatory growth and the slow community allocating more carbon to microbial biomass.
JOURNAL OF ECOLOGY
(2023)
Editorial Material
Geosciences, Multidisciplinary
Susan Trumbore, Ana Barros, Thorsten Becker, M. Bayani Cardenas, Eric Davidson, Nicolas Gruber, Eileen Hofmann, Mary Hudson, Tissa Illangasekare, Sarah Kang, Alberto Montanari, Marcos Moreno, Francis Nimmo, Larry Paxton, Vincent J. M. Salters, David Schimel, Bjorn Stevens, Hang Su, Donald Wuebbles, Peter Zeitler, Binzheng Zhang
Summary: The editorial board of AGU Advances expresses gratitude to the individuals who reviewed manuscripts for the journal in 2022. Thanks to the 131 reviewers who contributed to AGU Advances in 2022.
Article
Ecology
Markus Krueger, Narendrakumar Chaudhari, Bo Thamdrup, Will A. Overholt, Laura A. Bristow, Martin Taubert, Kirsten Kuesel, Nico Jehmlich, Martin von Bergen, Martina Herrmann
Summary: The study reveals that complete ammonia-oxidizing bacteria (CMX) of the genus Nitrospira have a competitive advantage over ammonia-oxidizing bacteria (AOB) and archaea (AOA) in oligotrophic carbonate rock aquifers, due to their ecophysiological characteristics and wide occurrence in groundwater. However, their specific contribution to nitrification processes has been unclear. The research aimed to unravel the contribution of CMX, AOA, and AOB to nitrification and identify the environmental drivers of their niche differentiation in oligotrophic carbonate rock aquifers.
Article
Plant Sciences
David Herrera-Ramirez, Henrik Hartmann, Christine Roemermann, Susan Trumbore, Jan Muhr, Leonardo Maracahipes-Santos, Paulo Brando, Divino Silverio, Jianbei Huang, Iris Kuhlmann, Carlos A. Sierra
Summary: This study aims to explore the seasonal carbon dynamics of mature trees by investigating the influence of starch content and distribution in stemwood. The results show that semi-deciduous/fibre-storing species have greater temporal variation in carbon sink activities and more seasonally dynamic starch content, indicating a possible trade-off between growth and storage. These findings provide insights into the survival and life span of different tree species.
JOURNAL OF ECOLOGY
(2023)
Article
Agronomy
Tom Guhra, Arnold Wonneberger, Katharina Stolze, Thomas Ritschel, Kai Uwe Totsche
Summary: This study investigates the role of cutaneous earthworm mucus (CEM) in soil organic-mineral associations and aggregation. The results suggest that pH and concentration affect the adsorption of CEM to goethite. Furthermore, mucus-mineral associations contribute to soil structure and nutrient storage.
JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE
(2023)
Article
Ecology
Shane W. Stoner, Marion Schrumpf, Alison Hoyt, Carlos A. Sierra, Sebastian Doetterl, Valier Galy, Susan Trumbore
Summary: Carbon (C) in soils persists on different timescales depending on physical, chemical, and biological processes. Thermal fractionation has shown promise for separating young from old C by decomposing soil organic matter (SOM) at increasing heat levels. This study investigates the age distribution of C in different fractions separated by density and chemical properties using radiocarbon (C-14) and C-13 analysis during thermal fractionation.
Article
Environmental Sciences
Saqr Munassar, Guillaume Monteil, Marko Scholze, Ute Karstens, Christian Roedenbeck, Frank-Thomas Koch, Kai U. Totsche, Christoph Gerbig
Summary: This study analyzes the impact of atmospheric transport on estimating CO2 fluxes over Europe in 2018 using two atmospheric inversion systems. The main focus is to quantify the drivers of spread in CO2 estimates from atmospheric tracer inversions. The results show that differences in the mesoscale transport model contribute the most to the discrepancies in annual budget, followed by far-field contributions and the inversion systems. Varying the mesoscale transport leads to large discrepancies in spatial and temporal patterns, while changing the lateral boundary conditions result in more homogeneous impact. The choice of inversion system and prior error structure also have significant impacts on the CO2 estimates.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Soil Science
Martina Herrmann, Katharina Lehmann, Kai Uwe Totsche, Kirsten Kuesel
Summary: The translocation of soil microorganisms across the soil-regolith boundary through seepage plays a vital role in connecting surface and subsurface habitats. This study investigated the factors influencing this translocation and found that the taxonomic identity of bacteria and the seasonal infiltration regime were the main drivers. The results highlight the continuous export of substantial bacterial biomass from soils to subsurface environments and suggest that the introduction of bacterivorous or potential pathogenic taxa from soil to groundwater may be an important factor in groundwater food webs.
SOIL BIOLOGY & BIOCHEMISTRY
(2023)
