Filtering by Subject: Biogeochemistry
Published: 2023-09-26
Subjects: Biogeochemistry, Environmental Microbiology and Microbial Ecology Life Sciences, Geochemistry, Paleobiology
Microbial mats and microbialites are essential tools for reconstructing early life and its environments. To better understand microbial trace element cycling, a microbial mat was collected from the sinkhole systems of the western shores of the Dead Sea, a dynamic environment exhibiting diverse extreme environments. Intense arsenic enrichment (up to 6.5 million times higher than current water [...]
Published: 2023-09-25
Subjects: Biogeochemistry, Climate, Earth Sciences, Geomorphology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Arctic permafrost, the largest non-seasonal component of Earth’s cryosphere, contains a significant climate-sensitive carbon pool. Its potential for loss due to climatic changes leading to a global tipping point, where thawing accelerates with disproportionate impacts, remains debated. Here, we provide an integrative perspective on this question, building on a cross-disciplinary meta-analysis of [...]
Published: 2023-09-20
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Microbiology
Reactive iron (FeR) has been suggested to serve as a semi-persistent sink of organic carbon (OC) in surface marine sediments, where approximately 10-20% of total OC (TOC) is associated with FeR (FeR-OC). However, the persistence of FeR-OC on geological timescales remains poorly constrained. Here, we retrieved FeR-OC records in two long sediment cores of the northern South China Sea spanning [...]
Published: 2023-09-05
Subjects: Atmospheric Sciences, Biogeochemistry, Earth Sciences
Published: 2023-08-17
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Physical Sciences and Mathematics, Soil Science
Microbial carbon use efficiency (CUE) is defined as the proportion of microbial biomass growth C versus substrate C uptake, and thus provides a useful measure of microbially driven accumulation and loss of soil organic carbon (SOC) 1. In a recent study published in Nature 2, the authors use a data-driven machine learning approach to conclude that CUE promotes global SOC storage based on a [...]
Published: 2023-07-18
Subjects: Biogeochemistry, Geochemistry
The oxidation of organic carbon contained within sedimentary rocks (“petrogenic” carbon, or hereafter OCpetro) emits nearly as much CO2 as is released by volcanism, thereby playing a key role in the long-term global C budget. High erosion rates in mountains have been shown to increase OCpetro oxidation. However, these settings also export un-weathered material that may continue to react in [...]
Published: 2023-07-04
Subjects: Biogeochemistry, Geochemistry, Soil Science
The mechanisms underlying stabilization of soil organic matter (SOM) in coastal ecosystems, including mangrove forests, are poorly understood, limiting our ability to predict the consequences of disturbances. Here, we introduce density fractionation to mangrove soils to identify the distribution and properties of the functional components of SOM with regard to degradation state, stability, and [...]
Published: 2023-06-28
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology
Earth system models (ESMs) are progressively advancing towards the kilometer scale (k-scale). However, the surface parameters for Land Surface Models (LSMs) within ESMs running at the k-scale are typically derived from coarse resolution and outdated datasets. This study aims to develop a new set of global land surface parameters with a resolution of 1 km for multiple years from 2001 to 2020, [...]
Published: 2023-06-14
Subjects: Biogeochemistry, Cosmochemistry, Databases and Information Systems, Geochemistry, Geology, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Geology, Volcanology
A vision of the not-to-distant future: Imagine yourself as a researcher who is making plans for fieldwork in the Andes Mountains. You are behind your computer and load a three-dimensional visualisation of the Earth and its geology to investigate the research already done in the southern Patagonian regions. You zoom in to the mountain range of interest and select various data layers to show [...]
Published: 2023-06-07
Subjects: Biogeochemistry, Oceanography and Atmospheric Sciences and Meteorology
This manuscript presents an overview of NASA’s EXport Processes in the Ocean from Remote Sensing 2021 Field Campaign in the North Atlantic (EXPORTS NA) and provides quantitative and dynamical descriptions of the physical processes modulating water transformations during the study. A major programmatic goal was to conduct the sampling in a Lagrangian mode so that ocean ecological and [...]
Published: 2023-05-28
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Hydrology
Rivers and streams play an important role within the global carbon cycle, in part through emissions of CO2 to the atmosphere. However, the sources of this CO2 and their spatiotemporal variability are difficult to constrain. Recent work has highlighted the role of carbonate buffering reactions that may serve as a source of CO2 in high alkalinity systems. In this study, we seek to develop a [...]
Published: 2023-05-15
Subjects: Biochemistry, Biophysics, and Structural Biology, Biogeochemistry, Biology, Microbiology
Life sustains itself using energy generated by thermodynamic disequilibria, commonly existing as redox disequilibria. Metals are significant players in controlling redox reactions, as they are essential components of the engine that life uses to tap into the thermodynamic disequilibria necessary for metabolism. The number of proteins that evolved to catalyze redox reactions is extraordinary, as [...]
Published: 2023-05-08
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial lipids that have been largely used as environmental proxies in continental paleorecords. Another group of related lipids, branched glycerol monoalkyl glycerol tetraethers (brGMGTs), has recently been proposed as a potential paleotemperature proxy. Nevertheless, the sources and environmental dependencies of both brGDGTs and [...]
Published: 2023-04-29
Subjects: Biogeochemistry, Geochemistry
We present the first measurement of bioavailable strontium (87Sr/86Sr) and lead (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb) isotope ratios from five cattle bones and one soil sample from Erenda, a chalcolithic site in coastal east India. Bioavailable 87Sr/86Sr of bones differ from that of the soil. A similar Pb isotope ratios of bones to the soil indicates an insignificant diagenesis and local [...]
Published: 2023-04-15
Subjects: Biogeochemistry
Microbial processing of soil organic matter is a significant driver of C cycling, yet we lack an understanding of what shapes the turnover of this large terrestrial pool. In part, this is due to limited options for accurately identifying the source of C assimilated by microbial communities. Laboratory incubations are the most common method for this; however, they can introduce artifacts due to [...]