Preprints
Filtering by Subject: Biogeochemistry
Global temperature calibrations based on 3-hydroxy fatty acids in lacustrine settings
Published: 2026-08-22
Subjects: Biogeochemistry, Earth Sciences
Lakes are important archives of palaeoclimate records on the continent and decoding them could improve the parameterization of climate models to better predict the future. However, the limited temperature proxies currently applicable in lake environments make high-resolution climate records scarce. 3-hydroxy fatty acids (3-OH FAs) are bacterial lipids which have recently been proposed as [...]
State-Dependent Biophysical Processes Prevented a Late Paleozoic Snowball Earth
Published: 2026-08-21
Subjects: Biogeochemistry, Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Terrestrial vegetation modulates Earth’s climate through two distinct pathways—biogeochemically drawing down CO2 through enhanced organic carbon burial [1, 2] and silicate weathering [3, 4], and biophysically altering surface energy and water balances through potentially competing albedo and evapotranspiration changes [5, 6]. Although the biogeochemical pathway is widely invoked to explain the [...]
Predicting the reactivity of trawl-disturbed sediment carbon from measurable seabed properties
Published: 2026-08-16
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Mobile bottom-contact fishing gear disturbs a large area of the continental shelf each year. How much carbon that releases depends on how fast the disturbed material is mineralised. Assessments represent that with a first-order rate constant, and because its value is unmeasured they sample it across five orders of magnitude, which makes it their dominant uncertainty. Here the constant is derived [...]
Mineral association drives divergent chemical trajectories of organic sulfur during dryland soil development
Published: 2026-08-15
Subjects: Biogeochemistry, Earth Sciences, Soil Science
Sulfur (S) deficiency is becoming more widespread as atmospheric S deposition declines, increasing ecosystem reliance on mineralization of soil organic S as a source of plant-available sulfate. Yet how organic S chemistry evolves during soil development, and how this evolution is mediated by microbial processing and mineral association, remains poorly understood, particularly in drylands. Here, [...]
Moving fast without breaking things: The benefits of preprinting for CDR research
Published: 2026-08-06
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Other Earth Sciences, Other Environmental Sciences
Advocates of preprinting usually focus on its benefits to individual researchers — more feedback, citations, and visibility. We argue its greater value is collective: preprinting improves scientific coordination, which the carbon dioxide removal field needs in order to move fast without sacrificing rigor.
River dissolved inorganic carbon losses from the Andes to lowland Amazon via cryptic sedimentary exchange processes
Published: 2026-08-05
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Hydrology
River carbon transfers and associated greenhouse gas emissions are a major component of the carbon cycle. Proposals to use rivers and their catchments to increase carbon dioxide (CO2) drawdown, by enhanced rock weathering and river alkalinity enhancement, require secure delivery of dissolved inorganic carbon (DIC) and increased cation loads (e.g. Ca2+) to the ocean. Here we explore the fate of [...]
Effective Microbial Kinetics under Pore-Scale Transport Limitation: A Biofilm Effectiveness-Factor Theory
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics
Reactive-transport models of porous media usually evaluate microbial reactions with Monod kinetics and rate constants measured on well-mixed laboratory cultures, in which every cell is exposed to the same substrate concentration. In natural sediments and aquifers this assumption fails at the pore scale, because the cells are not suspended but reside in biofilms and aggregates attached to the [...]
Connectivity effects on fluid age and residence time distributions in two- and three-dimensional pore networks
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Pore-scale simulations are often run on a single plane cut from a three-dimensional image, because resolving the whole pore space is expensive. This study asks what that shortcut costs. What is at stake is the distribution of fluid ages, and above all its long tail, because that tail is what slow reactions respond to. We computed the distribution directly from the flow field, by labeling the [...]
Reconstructing age and reactivity distributions from the moments carried by central-moment transport models
Published: 2026-07-26
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
A central-moment transport model follows a property that varies across a population, such as the age of water parcels or the decay rate of organic-matter particles. Instead of storing the whole distribution of that property, it keeps only a few summary numbers, the moments, and moves those through the model. But the distribution itself is usually what a scientist wants, so it has to be rebuilt [...]
Soil acidity governs cropland phosphorus availability under future climate
Published: 2026-07-21
Subjects: Agriculture, Biogeochemistry, Soil Science
Understanding the response of agricultural phosphorus (P) cycling to climate change is fundamental for ensuring global food security and protecting planetary boundaries1–2. Recently, Wang et al.3 reported a drastic reduction in soil P bioavailability (32–34%) under long-term elevated carbon dioxide (eCO2) and warming in rice paddies, attributing it to enhanced geochemical sequestration via [...]
Glycerolipids track sinking particle sources and remineralization in two ocean basins
Published: 2026-07-15
Subjects: Biogeochemistry, Geochemistry, Oceanography
The biological carbon pump is a major control on ocean carbon storage. On long time scales, changes in the biological carbon pump modulate atmospheric CO2 concentrations and climate. Attenuation in sinking carbon fluxes is derived from a combination of remineralization by bacteria, zooplankton, and fragmentation. However, the importance of these attenuation processes varies spatially and [...]
The Rise of Diamond Open Access Journals in Earth Sciences: Past Developments, Present Tensions, and Future Pathways
Published: 2026-07-08
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Library and Information Science, Paleontology, Planetary Sciences, Sedimentology, Tectonics and Structure, Volcanology
Over roughly the last decade, a visible, community-led Diamond Open Access (OA) ecosystem has emerged in the Earth sciences, not as a departure from tradition, but as the latest expression of a long-standing culture of open, society-supported scholarly communication. While free-to-read, fee-free publishing initiatives have deep roots in the field, predating the Diamond terminology by decades and [...]
From linguistic evaluation to mechanistic verification: testing LLM-generated farm recommendations
Published: 2026-07-03
Subjects: Agricultural Science, Agriculture, Agronomy and Crop Sciences Life Sciences, Biochemistry, Biophysics, and Structural Biology, Biogeochemistry, Environmental Indicators and Impact Assessment, Research Methods in Life Sciences, Soil Science, Sustainability
Large language models (LLM) are increasingly used to generate farm-management advice, but their biophysical consequences remain largely unverified. We introduce a process-based verification framework that combines management portfolios generated by ChatGPT and Claude with the process-based model LandscapeDNDC across 11 contrasting agroecosystems. The LLMs produced agronomically plausible [...]
Spectrally structured CNN encoding for interpretable and edge-ready fractional vegetation cover mapping using UAS multispectral and imaging spectroscopy
Published: 2026-06-30
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
Fractional vegetation cover (FVC) is a key indicator of semi-arid ecosystem condition, but non-photosynthetic vegetation (NPV) remains difficult to map because dry or senescent vegetation, litter, woody debris, and standing dead material can overlap spectrally with photosynthetic vegetation (PV) and bare ground (BE), especially where shadows, exposed bare earth surfaces, and mixed vegetation-soil [...]
Tectonic pump closes the evolutionary loop for long-buried subseafloor microbes
Published: 2026-06-22
Subjects: Biogeochemistry, Geophysics and Seismology, Hydrology, Tectonics and Structure
Deep marine sediments host one of Earth’s largest microbial biospheres, yet most cells in this environment persist in a non-growing state for thousands to millions of years beneath kilometers of sediment. For natural selection to favor such extraordinary long-term survival, a mechanism must exist that is capable of returning buried living populations to near-surface environments, where [...]