Article
Multidisciplinary Sciences
Jonathan Gropp, Qusheng Jin, Itay Halevy
Summary: This paper develops a metabolic-isotopic model of methanogenesis and explains multiple isotopic patterns in laboratory and natural settings. It also provides predictions for the biomass-specific methanogenesis rates.
Article
Geography, Physical
Shunchuan Ji, Long Ma, Junsheng Nie, Shengyun Chen, Youbin Sun, Daniel O. Breecker
Summary: Soil respiration is crucial for understanding CO2 fluxes, with spatial S(z) variations mainly controlled by monsoonal precipitation. Monitoring work in higher precipitation areas is needed for better constraint of S(z) values.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Soil Science
Mengguang Han, Jiguang Feng, Ying Chen, Lijuan Sun, Liangchen Fu, Biao Zhu
Summary: The study showed that R-Myc is a significant component of soil respiration, contributing to both soil respiration and autotrophic respiration. It exhibits a different geographical pattern from R-Root and should be considered separately in terrestrial carbon cycling models.
SOIL BIOLOGY & BIOCHEMISTRY
(2021)
Article
Environmental Sciences
Mark A. Brzezinski, Ivia Closset, Janice L. Jones, Gregory F. de Souza, Colin Maden
Summary: The silicon isotope composition of silicic acid in the deep Arctic Ocean is anomalously heavy compared to other ocean basins. The study shows that the isotope values reflect local processes such as drift waters influence and benthic inputs, as well as overall inflow-outflow similarity. Biological productivity and opal burial play a major role in removing light isotopes entering the Arctic Ocean from rivers.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Soil Science
Peng Chen, Xiao-Liang Yuan, Lin -Yang Li, Jun-Ya Li, Run-Qin Zhang, Zhi-Guo Li, Yi Liu
Summary: Land-use type influences CO2 emission fluxes, delta(CO2)-C-13, and the effects of heterogeneity in soil microenvironment. This study investigated the effects of land-use type on soil-respired CO2 and delta(CO2)-C-13 using long-term soil incubation and fractionation techniques. Results showed that woodland had the highest soil respiration rates and exhibited a shift in delta(CO2)-C-13 values. Aggregational differentiation of soil-respired CO2 and delta C-13 was found only in the woodland, and warming intensified these differences. These findings are important for understanding the feedback of soil carbon pool to global warming.
Article
Environmental Sciences
Jeffrey Beem-Miller, Marion Schrumpf, Alison M. Hoyt, Georg Guggenberger, Susan Trumbore
Summary: The study shows that air-drying and rewetting of soils significantly affect increment C-14-CO2, especially with stronger impacts on grassland soils. Storage duration does not have a substantial effect. Air-drying and rewetting mobilize a slightly older pool of carbon accessible to microbes, with this effect persisting throughout the incubation period.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)
Article
Environmental Sciences
Gianmarco Ingrosso, Michele Giani, Martina Kralj, Cinzia Comici, Paola Rivaro, Giorgio Budillon, Pasquale Castagno, Luca Zoccarato, Mauro Celussi
Summary: The Antarctic continental shelf is an important sink for anthropogenic carbon dioxide, but climate change is altering its carbon cycle. Summer biological activity plays a key role in the sequestration of anthropogenic carbon.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Marie Spohn, Stefan Holzheu
Summary: The study reveals that soil CO2 concentration increases linearly with depth in desert soil, showing a diel oscillation that decreases with soil depth as well as a hysteretic relationship between topsoil CO2 concentration and air/soil temperature. Thermal convective venting is likely responsible for the observed dynamics, suggesting a significant control of temperature differences on gas exchange within soil systems.
Article
Plant Sciences
Chongyu Ye, Qiangfa Zeng, Keda Hu, Dongming Fang, Dirk Hoelscher, Huaqiang Du, Yongjun Shi, Yufeng Zhou, Frank Berninger, Tingting Mei, Guomo Zhou
Summary: Stem respiration is an important process in ecosystem carbon cycling. However, the measured efflux on the stem surface may not represent the actual respiration. This study proposes stem photosynthesis as an additional pathway and conducts experiments on newly sprouted bamboo to explore the partitioning of stem respiration.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Geochemistry & Geophysics
Sebastian Jimenez-Rodriguez, Jay Quade, Naomi E. Levin, Christopher J. Campisano, Gary E. Stinchcomb, Diana C. Roman, Zelalem Bedaso
Summary: Hydrogen stable isotope values of hydrated volcanic glass from the Afar region in eastern Ethiopia show a wide distribution, indicating past climate variations. The isotopic values of volcanic glass are lower than those of soil carbonates, suggesting the influence of surface evaporation on isotopic enrichment.
Article
Environmental Sciences
Mariah S. Carbone, Andrew D. Richardson, Billy Barr, Max Berkelhammer, Claudia M. Boot, Austin Simonpietri, Christopher J. Still
Summary: Long-term soil CO2 emission measurements are crucial for understanding trends and variability in the terrestrial carbon cycle. This study conducted continuous measurements in two high elevation forest types in the upper Colorado River basin and found that snowfall and rainfall had significant impacts on soil CO2 flux, with greater sensitivity to rainfall. Furthermore, the study observed a decline in surface soil CO2 production due to warming and reduced summer rainfall.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
C. Schmitt, P. Moller
Summary: A newly developed method based on the BSM model was used to calculate fission-fragment isotopic yields Y(Z, N). Recent measurements with high resolution allow for detailed testing of the model. The comparison between measured and calculated fission fragment average neutron number N N with Z shows consistent results.
Article
Geochemistry & Geophysics
Jessica A. Lueders-Dumont, Atleigh G. Forden, Emma R. Kast, John A. Mohan, Benjamin D. Walther, Daniel M. Sigman, Bess B. Ward
Summary: The use of nitrogen isotopes can effectively track the life history of organisms following dietary changes. Otoliths and tissues show different response times to new diets, with slower growth tissues exhibiting larger variations. Further optimization of sampling methods may improve resolution for tracking diet changes.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geography, Physical
Vijayananda Sarangi, Shailesh Agrawal, Prasanta Sanyal
Summary: The study reveals discrepancies in estimating the abundance of C-3-C-4 plants using different proxies due to variations in response to changes in vegetation and ecological conditions. Different proxies in paleosols exhibit diverse isotopic fractionation processes, leading to uncertainties in estimating plant abundances from soil components.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
Shuai Cui, Weiqi Wang, Chuanbao Cheng, Ying Yao, Chaojian Qin, Qiang Sun
Summary: Raman spectroscopy is an efficient method for quantitatively measuring the carbon isotopic composition of CO2, but the low concentration of (CO2)-C-13 in natural samples can impact the accuracy and precision of the measurement. A method is proposed to improve the accuracy and precision of measured (CO2)-C-13/(CO2)-C-12 ratios.