Preprints
Filtering by Subject: Biogeochemistry
Spatial autocorrelation inflates the global leaf-wax d2H-precipitation slope
Published: 2026-06-19
Subjects: Biogeochemistry, Earth Sciences, Geochemistry
Leaf wax hydrogen isotope ratios (δ²Hwax) are used to make inferences about past hydroclimate, but global calibrations between δ²Hwax and precipitation isotopes (δ²Hprecip) ignore spatial autocorrelation and inflate apparent relationships. This study compiled 1,129 surface sediment and soil measurements of δ²Hwax from n-C29 alkanes and developed hierarchical Bayesian spatial models to separate [...]
Reactive soil inputs during high-flow events decouple carbon chemistry and CO2 evasion in a granitic headwater stream
Published: 2026-06-11
Subjects: Biogeochemistry, Hydrology
Quantifying CO2 dynamics in low-alkalinity headwater streams is challenging because thermodynamically based evaluations of pCO2 and CO2 fluxes (FCO2) assume coherent DIC-alkalinity-pH coupling. This study examines how hydrologically driven disturbances violate this assumption in a forested, granitic headwater stream using 15 months of calculated pCO2 and FCO2, alongside measurements of pH, [...]
Subsurface advective flow unveils the architecture of Earth’s crustal biosphere
Published: 2026-06-09
Subjects: Biogeochemistry, Environmental Microbiology and Microbial Ecology Life Sciences, Geology, Microbiology, Other Earth Sciences, Other Environmental Sciences
The subsurface biosphere is one of Earth’s largest microbial reservoirs, yet its spatial extent remains poorly constrained due to limited direct access. Here we propose using the integrated environmental readouts encoded in deep subsurface fluids to shift from simply mapping where life can be detected to constraining where life can exist. Deeply-sourced advective fluids provide an integrated [...]
Mineral stabilization of soil organic sulfur at the continental scale
Published: 2026-06-01
Subjects: Biogeochemistry, Life Sciences, Physical Sciences and Mathematics, Soil Science
Declining atmospheric sulfur (S) deposition makes S an emerging limiting macronutrient to plants, yet the stability and dynamics of soil organic S - the largest terrestrial S pool supplying plant-available sulfate via mineralization - remain unclear. Across North American soils, mineral-associated organic S (MAOS), a stabilized pool by mineral protection, dominates (61 ± 26% of the total soil S) [...]
ATMOSPHERIC DEPOSITION AND SOURCE APPORTIONMENT OF MERCURY AND LEAD OVER THE LAST 150 YEARS IN HIGHLAND PEATLANDS OF SOUTHEASTERN BRAZIL
Published: 2026-05-28
Subjects: Biogeochemistry, Geochemistry
Trace elements like mercury (Hg) and lead (Pb) are major global pollutants subject to long-range atmospheric transport, posing a threat for human and environmental health at a global scale. Both have a great affinity with organic matter and show limited mobility in soils under stable environmental conditions. Therefore, peatlands efficiently trap and act as reliable archives of changes in [...]
Marine Heatwaves Disrupt Phytoplankton Communities Through Trait-dependent Selection
Published: 2026-05-24
Subjects: Biodiversity, Biogeochemistry, Climate, Marine Biology
Phytoplankton communities, key regulators of marine ecosystems and the global carbon cycle, are susceptible to sea surface temperature variability, such as marine heatwaves (MHWs). However, their trait-dependent responses and the resulting compositional shifts during MHWs remain poorly understood. Here, using an advanced global ocean–biogeochemical model that resolves 310 phytoplankton trait [...]
From 2D labels to 3D structure: Scalable label transfer and benchmarking of 3D vegetation models in rangeland ecosystems
Published: 2026-05-03
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: 2026-05-01
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: 2026-05-01
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: 2026-04-21
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Other Environmental Sciences
Earth history includes episodes in which persistent biological or geophysical byproduct loads are absorbed by finite environmental sinks and buffers, preserving apparent stability while the capacity to absorb further stress declines. This paper synthesizes literatures on Earth system revolutions, redox transitions, mass extinctions, and Anthropocene change into a comparative framework termed [...]
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 [...]