Preprints
Filtering by Subject: Biogeochemistry
From 2D labels to 3D structure: Scalable label transfer and benchmarking of 3D vegetation models in rangeland ecosystems
Published: 2026-05-02
Subjects: Artificial Intelligence and Robotics, Biogeochemistry, Computer Sciences, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics, Remote Sensing
Three-dimensional (3D) characterisation of vegetation structure at the level of individual growth forms is critical for understanding ecosystem function and resilience, yet remains challenging in rangelands because vegetation is sparse, low-stature, and structurally heterogeneous. Recent 3D deep-learning models perform strongly in forests, but their transfer beyond closed-canopy benchmarks is [...]
Reduced geomagnetic shielding increased UV-B radiation at Earth’s surface during the Laschamps Event
Published: 2026-04-30
Subjects: Astrophysics and Astronomy, Atmospheric Sciences, Biochemistry, Biogeochemistry, Biology, Earth Sciences, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Geology, Geophysics and Seismology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Life Sciences, Paleobiology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences, Statistics and Probability
Exposure to excess UV-B radiation can harm organisms through DNA damage and oxidative stress, and has likely been a key ecological and evolutionary driver throughout Earth’s history. Here, we show UV-B at Earth’s surface was significantly increased during the Laschamps Event, the last major geomagnetic excursion ca. 41ka BP. During the Laschamps, we find significant and prolonged (lasting [...]
Direct quantification of solar-induced chlorophyll fluorescence using compact solar-blind optical radiometers
Published: 2026-04-30
Subjects: Biogeochemistry, Earth Sciences, Environmental Monitoring, Environmental Sciences, Optics, Physical Sciences and Mathematics, Physics
Remote sensing of solar-induced chlorophyll fluorescence (SIF) provides a non-invasive, quantitative measure of plant photosynthetic activity, linking leaf-level physiology to canopy and ecosystem behavior and the global carbon cycle. Current SIF measurements rely on hyperspectral retrievals of the weak fluorescence signal from small changes in Fraunhofer lines or atmospheric absorption features [...]
Long-term future Greenland ice loss determined by peak global warming
Published: 2026-04-29
Subjects: Biogeochemistry, Climate, Glaciology
The Greenland ice sheet (GrIS) is known to be very sensitive to climate change, and persistent global warming only slightly higher than today could be enough to completely melt it. However, the implications of a temporary crossing of this temperature threshold for future GrIS mass loss remain unknown. Here we present simulations of the next 10,000 years under different future anthropogenic [...]
Erosion-driven changes in soil cation exchange capacity quantified using barium isotopes
Published: 2026-04-22
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Physical Sciences and Mathematics, Soil Science
Human activities have perturbed the balance between rates of soil erosion and formation, driving declines in soil quality. However, quantifying these soil imbalances remains challenging, especially at large scales. Here we present a novel isotope mass balance approach that can be used to quantify river catchment wide rates of change in cation exchange capacity (CEC), a key soil quality metric, in [...]
Before the Threshold: Deceptive Stability, Buffer Slack, and Earth System Transitions
Published: 2026-04-20
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Other Environmental Sciences
Earth history includes episodes in which biological or geophysical processes generate persistent byproduct loads whose early effects are partially masked by environmental sinks and buffering pathways. This paper synthesizes established literatures on Earth system revolutions, redox transitions, mass extinctions, and Anthropocene change into an explicit phase grammar termed Buffered Byproduct [...]
Agent-based Modelling of Microbialite Formation through Sedimentation and Precipitation Dynamics
Published: 2026-04-13
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Fossil microbialites resulting from the interplay of sedimentation and microbially induced precipitation are among the oldest evidence of life on Earth and help geobiologists interpret many sedimentary environments. However, the factors governing their internal structure and external morphology are still poorly understood. Additionally, abiotic processes can mimic the morphology of some [...]
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 disturbance and tree mortality dynamics from Sentinel-2 time series around 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: 2026-01-24
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 [...]