Preprints
Filtering by Subject: Biogeochemistry
Low-cost autonomous chambers enable high spatial and temporal resolution monitoring of soil CO₂ exchange across landscapes
Published: 2025-08-15
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Environmental Engineering, Environmental Indicators and Impact Assessment, Meteorology, Natural Resources and Conservation, Soil Science, Sustainability, Terrestrial and Aquatic Ecology
1. Soil CO₂ flux is a critical component of ecosystem carbon cycling, but due to high cost and mechanistic constraints, existing measurement systems are often limited by trade-offs between resolution (temporal and spatial), and spatial coverage. These constraints hinder efforts to monitor soil fluxes across diverse, heterogeneous landscapes and environmental gradients. 2. We developed Fluxbot [...]
Dual and divergent formation pathways govern the composition and origins of mineral-associated organic carbon
Published: 2025-08-13
Subjects: Biogeochemistry, Terrestrial and Aquatic Ecology
Mineral-associated organic matter (MAOM) is the largest and most stable soil carbon reservoir, playing a central role in soil health and climate mitigation. Yet, quantitative understanding is lacking for the two fundamental processes forming MAOM— adsorption of dissolved organic matter and aggregation of insoluble organic particles—and how each pathway incorporates plant- versus microbial-derived [...]
The Global Woody Surface: A Planetary Interface for Biodiversity, Ecosystem Function, and Climate
Published: 2025-08-07
Subjects: Biogeochemistry, Ecology and Evolutionary Biology, Forest Sciences, Natural Resources and Conservation
Global woody surfaces span an area nearly equivalent to Earth’s terrestrial land surface and mediate CO2 fluxes three times larger than global fossil fuel emissions and methane uptake comparable to the global soil sink, yet remain absent from ecological research and Earth system models despite their critical roles in biodiversity and ecosystem services.
Simulated Soil Respiration is Sensitive to Soil Hydraulic Properties from Intact vs. Repacked Cores
Published: 2025-07-05
Subjects: Biogeochemistry, Hydrology, Soil Science
Soil hydraulic properties, such as water retention and hydrodynamics, play a pivotal role in regulating belowground carbon (C) storage by influencing microbial activity and nutrient availability. However, empirical measurements of these properties are labor-intensive and often fail to replicate field conditions in laboratory settings. Standardizing and increasing the throughput of hydraulic [...]
Continental-Scale Carbonate Sedimentation and Environmental Correlates of the Shuram-Wonoka Excursion
Published: 2025-07-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Strata of the Ediacaran Period record many Earth-Life features that distinguish the Neoproterozoic-Phanerozoic transition. However, it is difficult to determine cause and effect relationships between Ediacaran events. Continental-scale patterns of sedimentation have been used as proxies to investigate controls on Phanerozoic macroevolution, including sea level drivers and potential carbon cycling [...]
Combined thermodynamic-kinetic-competitive controls on anaerobic respiration pathways and the chemistry of natural waters
Published: 2025-06-13
Subjects: Biogeochemistry, Earth Sciences
Microbial metabolisms underpin geochemical cycling in nearly all of the Earth's biosphere. Anaerobic pathways of carbon mineralization by iron and sulfate reduction and methanogenesis, in particular, have existed over most of Earth history and have been central in shaping the chemistry of the oceans and atmosphere. The governing principles by which microbial metabolisms contribute to water-column [...]
Phytoplankton variable stoichiometry modifies key biogeochemical fluxes and the functioning of the ocean biological pump
Published: 2025-05-27
Subjects: Biogeochemistry, Oceanography
Ocean biota absorb carbon at the surface and export some to the ocean interior via the biological pump, affecting surface carbon, air-sea CO₂ exchange, and climate. Marine phytoplankton growth is often limited by nutrients (nitrogen, phosphorus, iron, silicon). The efficiency of carbon export is therefore constrained by nutrient availability and the nutrient/carbon ratios in the biota [...]
Calcium isotope constraints on Mesoarchean seawater
Published: 2025-04-24
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology
The cause of the Great Oxidation Event ~2.4 billion-years-ago (Ga) is hotly debated. Recent models favor the emergence of continents as driving the event. However, we suggest that extensive shallow-marine carbonate platforms existed in the Mesoarchean. This conclusion is based on Ca isotopes from 2.8 Ga carbonate rocks, that constrains the Ca isotope value of Mesoarchean seawater to -0.5‰ [...]
Mercury budget in global rivers at present-day: impacts from reservoirs and dams
Published: 2025-03-14
Subjects: Biogeochemistry, Earth Sciences, Environmental Health and Protection, Environmental Monitoring, Environmental Sciences, Water Resource Management
Many world rivers are currently polluted by mercury (Hg) compounds, leading to the bioaccumulation of methylmercury (MeHg) in the food web, which poses potential health risks to humans. However, the riverine Hg budgets of global scale remain poorly understood due to limited observations, complicating efficient environmental governance. Here, we employ a process-driven Hg model to track its [...]
Phytoplankton blooms in the new Southern Ocean sea ice regime
Published: 2025-02-24
Subjects: Biogeochemistry, Geophysics and Seismology, Oceanography
Over the last decade, the Antarctic sea ice extent has recorded record highs and lows. The anomalous low in 2023 suggested a new reduced sea-ice state, with unknown impacts on phytoplankton blooms, including phenology and magnitude. Analysing both Biogeochemical (BGC) and Core Argo floats, we compare annual sea ice extent (SIE) anomalies and sea ice volume (SIV) to physical and biological [...]
Rewetting drained boreal peatland forests does not mitigate climate warming in the 21st century
Published: 2025-02-07
Subjects: Biochemistry, Biophysics, and Structural Biology, Biogeochemistry, Forest Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Sustainability
Rewetting of drained peatland forests restores ecosystem functions and improves peatland ecological status. It is also considered to mitigate climate change, yet some studies challenge this view Recently, Laine et al. (2024, Restoration Ecology, 32(7), p.e14213) considered feasible restoration outcomes of boreal forestry drained peatlands and proposed that rewetting nutrient-rich peatland forests [...]
Glacially enhanced silicate weathering revealed by Holocene lake records
Published: 2025-02-07
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
How glaciation affects CO2 drawdown by chemical weathering sets the strength of the weathering-climate feedback, which controls the exogenic carbon cycle and planetary habitability (Kump et al., 2000). However, the exact role of glaciers remains elusive as glaciation alters multiple factors controlling weathering, the net effect of which is ambiguous even in directionality. While illustrative, [...]
Challenges in Integrating Dissolved Organic Matter Chemodiversity into Kinetic Models of Soil Respiration
Published: 2025-01-25
Subjects: Biogeochemistry, Soil Science
The chemodiversity of dissolved organic matter (DOM) in soil has been proposed to influence the microbial metabolism and fate of belowground organic carbon (C). However, effectively integrating DOM chemistry into soil C cycle models to improve predictions of C stocks and fluxes—beyond simply considering DOM pool size—remains a challenge. While recent research suggests that incorporating DOM [...]
A bipolar convection seesaw explains Earth system response to Heinrich events
Published: 2025-01-24
Subjects: Biogeochemistry, Climate, Oceanography
GelCam: Visualizing Episodic Sinking Particle Flux via a Polyacrylamide Gel-Based Sediment Trap
Published: 2025-01-10
Subjects: Biogeochemistry, Earth Sciences, Oceanography
While particle-intercepting traps remain a dominant method for quantifying the contribution of sinking particles to the biological carbon pump, fluxes are typically integrated over days to months. Observations of time-varying particle flux over shorter durations are very limited. To this end, we prototyped a camera system called “GelCam” which captures a rapid time-lapse image sequence of [...]