Preprints
Filtering by Subject: Biogeochemistry
Lowering barriers to probing high-frequency variations in river chemistry through a frugal machine learning-based framework
Published: 2026-04-11
Subjects: Biogeochemistry, Environmental Monitoring, Hydrology, Water Resource Management
High-frequency river chemistry monitoring is crucial for capturing transient hydro-geochemical variations and ensuring water security, yet its implementation is limited by logistical and budgetary constraints. Here we present a machine learning-based framework that integrates continuous, low-cost physico-chemical proxies with sparse ‘anchoring’ solute measurements to reconstruct hourly-scale [...]
From geochemical to biogeochemical cycles: an organizational view of how (and why) life shaped its conditions of existence
Published: 2026-04-09
Subjects: Biochemistry, Biophysics, and Structural Biology, Biodiversity, Biogeochemistry, Earth Sciences, Life Sciences
Since the seminal work of Maturana and Varela, the Organizational Approach (OA) has defended an organism-centered view of life. This paper argues that the OA must be extended to include the historical, ecological and geochemical processes that sustain biological systems across scales. We develop a multiscale account of closure of constraints (CoC) in which localized closures can emerge and [...]
Natural organic matter coating changes the role of iron oxides in carbon preservation in marine sediments
Published: 2026-04-08
Subjects: Biogeochemistry
Preservation of organic carbon (OC) in marine and terrestrial depositional settings is enhanced by the association between OC and reactive iron oxides. However, microbially mediated iron reduction in anoxic marine sediments may lead to the reductive dissolution of iron oxides and consequently to the remobilization of iron-associated organic matter. The underlying mechanism remains poorly studied. [...]
Introducing Microalgae Carbon Fixation and Sinking (MCFS): a new approach for controlled and scalable CDR
Published: 2026-04-08
Subjects: Biogeochemistry, Climate, Oceanography, Other Oceanography and Atmospheric Sciences and Meteorology
Achieving global climate targets requires scalable and durable carbon dioxide removal (CDR) technologies to tackle both historical and hard-to- abate emissions. We introduce Microalgae Carbon Fixation and Sinking (MCFS), a marine CDR methodology designed to enhance carbon fixation and export to the deep ocean through a controlled process. At the core of the MCFS approach is a tailored substrate: [...]
Nickel Isotope Systematics in the Talvivaara Paleoproterozoic Black Shale Deposit Reveal Mineralogy-Controlled Fractionation with a Preserved Biogenic Signal
Published: 2026-04-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Nickel isotope systematics in sediment-hosted sulfide deposits are now more commonly used to infer redox and diagenetic processes, yet their potential to record biological signals and their preservation through diagenesis and metamorphism remains poorly constrained. Here we present micro-scale coupled δ60Ni, δ34S, δ13C, REE pattern, and paleoproductivity proxy data from the Paleoproterozoic [...]
Sub-pixel mapping of annual tree and standing deadwood cover from Sentinel-2 time series across the globe
Published: 2026-02-24
Subjects: Artificial Intelligence and Robotics, Biogeochemistry, Computer Sciences, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics
Elevated forest disturbances and excess tree mortality are increasingly reported worldwide. Yet existing assessments are either based on patchy terrestrial observations or on large-scale satellite products, which are limited in resolution to pixel-level, binary tree loss detection. This leaves a blind spot on fine-scale disturbances where only a few trees are declining in an otherwise intact [...]
Hybrid Physics–AI Ecosystem Simulations Improve Biogeochemical Predictions in Temperate Shelf Seas
Published: 2026-02-03
Subjects: Artificial Intelligence and Robotics, Biochemistry, Biogeochemistry, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Marine Biology, Numerical Analysis and Scientific Computing, Oceanography, Planetary Biogeochemistry, Terrestrial and Aquatic Ecology
Biogeochemical models form a core part of marine forecasting and climate projections, yet they suffer from persistent biases in predicting key ecosystem variables, creating challenges across regional and global scales. To address this, we developed an AI-augmented three-dimensional hybrid framework that integrates machine-learning corrections directly into a process-based model’s productivity [...]
Diel Dynamics of Zooplankton Fecal Pellet Flux Revealed by Integrated Optical Observations and Modeling
Published: 2026-01-23
Subjects: Biogeochemistry, Life Sciences, Marine Biology, Oceanography
The contribution of sinking fecal pellets to the biological carbon pump depends on pellet properties, producer abundance, and the depth and timing of pellet production, which can be modulated by diel vertical migration. We examined diel variability in zooplankton fecal pellet flux in the subarctic Northeast Pacific using two image-based tools: the Underwater Vision Profiler (UVP5) and [...]
Calcium promotes carbon rich grassland soils
Published: 2026-01-15
Subjects: Biogeochemistry
Dark colored grassland soils, known as Mollisols, are intensively farmed and exceptionally rich in organic matter, and hence have an important role in the carbon cycle. Elevated carbon storage in Mollisols may be facilitated by calcium (Ca) released by carbonate and silicate weathering. This synergy between carbon and Ca cycling has not been definitively quantified. To close this knowledge gap, [...]
Reviewing chronostratigraphic uncertainty of the Ediacaran-Cambrian transition
Published: 2026-01-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Stratigraphy
The Ediacaran-Cambrian transition archives the widespread disappearance of ‘Ediacaran-type’ soft-bodied biota and the appearance of most modern animal body plans, including a major diversification of skeletal animals and styles of animal-substrate interaction. Despite over a century of study, our ability to confidently reconstruct the series of macroevolutionary events that inform origination and [...]
Hydrological and landscape controls on dissolved organic matter dynamics in European wetlands
Published: 2025-12-28
Subjects: Biogeochemistry, Climate, Earth Sciences, Fresh Water Studies
Dissolved organic matter (DOM) is a key component in aquatic ecosystems, representing the main source of energy for microbial metabolism and playing a crucial role in C sequestration and export. Its optical properties (absorption and fluorescence) provide integrated information on its quality (average molecular weight and aromaticity degree, main sources, presence of protein like and humic-like [...]
Assessing the effects of restoration and conservation on gaseous carbon fluxes and climate mitigation potential across six European coastal wetlands
Published: 2025-12-23
Subjects: Biogeochemistry, Climate, Earth Sciences, Fresh Water Studies
Coastal wetlands play a substantial role in regulating Earth’s climate through exchanges of greenhouse gases (GHGs). Current European policies promote widespread coastal wetland restoration to reverse historical losses and ongoing pressures. However, substantial uncertainty remains regarding how carbon dioxide (CO2) and methane (CH4) fluxes respond to restoration across different coastal wetland [...]
Matters Arising: Critical Methodological Flaws in Qin et al. (2025) "Mangrove sediment carbon burial offset by methane emissions from mangrove tree stems"
Published: 2025-11-28
Subjects: Biogeochemistry, Earth Sciences
The authors report global mangrove stem CH₄ emissions of 730.60 Gg yr⁻¹, offsetting 16.9% of carbon burial. However, their analysis suffers from critical methodological flaws involving the failure to remove extreme statistical outliers, with 14.2% of chamber measurements and 15.5% of site observations identified as outliers by standard criteria. The analysis demonstrates inappropriate handling of [...]
Redox-network reconfiguration inferred from the ln[O2]-Eh relationship under mixed-potential conditions in a shallow pond time series
Published: 2025-11-23
Subjects: Biogeochemistry
Oxidation-reduction potential (Eh) is widely used as an in situ indicator of redox conditions in aquatic environments, and field electrodes typically record a mixed potential generated by multiple concurrent interfacial redox reactions. Beyond a simple Nernstian interpretation based on a single redox couple, here we ask what mechanistic information can be extracted from an observed relationship [...]
Legacy of peatland erosion shapes microbial communities during recovery
Published: 2025-11-14
Subjects: Biogeochemistry, Environmental Microbiology and Microbial Ecology Life Sciences
Human degradation of peatlands worldwide has turned them into net carbon sources. In upland blanket peatlands, erosion disrupts new plant-derived carbon input and exposes deep peat, putting old carbon at risk of oxidation. The efficacy of restoration in preventing carbon loss and recovering ecosystem function depends on microbial responses to both water table manipulation and renewed litter [...]