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Carbon Isotope - Astrophysics Data System

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Last Updated: 10 September 2022

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Investigating C3/C4 plants competition using carbon isotopes and optimality principles

Knowing the mechanisms that underlie carbon isotope discrimination in C3 and C4 plants is critical for predicting the C3/C4 fraction in mixed ecosystems. For example, isotopic fractionation during the diffusion of CO2 in C4 plants has the highest impact on u039313C in C3 plants, while fractionation during Rubisco carboxylation has a greater effect on C3 plants. As a result, C3 plants are depleted in 13C relative to C4 plants, which is depleted in 13C. We use the identical P model to investigate the abundance of C3 and C4 plants at various locations around the world to investigate the abundance of C3 and C4 plants. We now estimate the expected mean u039413C in soil organic materials after plants decomposition by plants decomposition using maps of C3/C4 plants distribution and analysis model predictions using real isotopic data.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.1111L/abstract


Tree-ring stable carbon isotope ratio (δ13C) and growth chronologies of more xeric Turkey oak (Quercus cerris L.) is reliable climate proxy than hydric pedunculate oak (Q. robur L.) species.

More extreme climate events have occurred in the 20th century and increased forest mortality, as a result of intensive climate changes. Different drought conditions exist in the Quercus sp. Quercus cerris and Q. robur from Serbia's Serbia are two of 20 radical growth and six stable carbon isotope ratio chronologies. A better match was obtained for u03b413C and more xeric Q. cerris and more xeric Q. cerris than for radial growth and Q. robur GAMMs results in the GAMM, with a greater number of 20 climate and environmental variables including more xeric Q. cerris than for deterministic growth and Q. robur GAMM results. Both u03b413C and radial growth, according to the results published in this study, xeric oak species such as Q. cerris are more susceptible to environmental conditions in both u03b413C and radial growth. According to the GAMM results, the more environmentally aware Q. cerris had greater correlations with the analyzed factors than Q. robur. Both oak species are characterized by research results and stress periods, with u03b413C responding more strongly and quickly to climatic anomalies than TRW, it was found that the analyzed climatic and environmental conditions can be a useful indicator of cambial growth and stress periods. The Slovenian Research Agency's financial support for research core funding No. 1 acknowledges the TL's recognition as a result of the Slovenian Research Agency's financial assistance. "Forest Biology, Ecology, and Technology" (Forte), as well as research grant J4-8216 – "mortality of lowland oak forests – a result of decreasing underground water or climate change?" In the same stand conditions, stable carbon isotope ratio and radial growth is closer to determining a more reliable climate indicator than hydric pedunculate oak:.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.2144K/abstract


Differences in stable carbon isotopic composition in the fine bulk aerosol and gas phases based on seasonally resolved data at a Prague site

At a suburban site in Prague, Czech Republic, Central Europe, we investigated seasonal variations in the stable carbon isotope ratio of total carbon and water-soluble organic carbon in fine aerosol particles, as well as total carbon of the gas phase. Acknowledgement: The Ministry of Education, Youth and Sports of the Czech Republic's No. 131 supported this conference, which indicated that the fractionation of stable carbon isotopes is primarily physical process in which the chemical composition of individual compounds in bulk aerosols does not play a significant role. Annual changes in stable carbon isotopic composition in the bulk aerosol and gas phases at a suburban site in Prague, Sci.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.1654V/abstract


Radiocarbon and stable C isotope variability of two Holocene stalagmites from the high-alpine Spannagel Cave

Stable carbon isotope results from stalagmites are often available as they are measured alongside stable oxygen isotopes. The latest LAAMS technique has made it possible to perform rapid and continuous analysis of 14C concentration in carbonate samples at spatial resolution down to 100 u03bcm. Combined b413C and 14C profiles made it possible to hypothesize on the interplay of regional climate and the contribution of an old organic C reservoir to stlagmite growth [3]. Here, we present the findings from a second Holocene stalagmite from Spannagel Cave's second Holocene stalagmite. This stalagmite grew at a location close to SPA 127 in terms of overlapping growth periods and consistent u03b418O signals [4]. The SPA 128 has a generally higher dcf and a more negative u03b413C, respectively suggesting the contribution of an old organic C reservoir to the stalagmite C. [1]D. Rudzka et al. , GCA 75, 4321-4339.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.3454W/abstract


Carbon isotope and organic geochemistry of the Holocene sediments from Rann of Kachchh: implications to the preservation of organic matter and climate during the Indus Valley Civilisation

Analysis of bulk sedimentary organic matter between C3 and C4 plants has been used to restore plant palaeoenvironmental conditions by determining u03b413C of bulk sedimentary organic matter. The sediments also undergo various stages of microbial decomposition, which can also change the original organic carbon source signatures. Following the commonly used dichromate oxidation method, the sediment samples were chemically treated for various oxidation times in an Indus Valley Civilization metropolis Dholavira, a UNESCO heritage site in the vicinity of the main location. After 72 hours, no more oxidation loss was recorded between pre- and post-treatment of SOM, suggesting that the remaining organic carbon is the most resistant phase. The isotopic composition would then represent the original isotopic signature of the refractory organic carbon. Local vegetation mainly controlled the organic matter composition, according to the u03b413C results of the core top sediment and the modern plants in Rann. In ten marine sediment samples from the northern Indian Ocean, the oxidation process was also tested by analyzing u03b413COROC and u03b413CSOM, indicating the retention of marine organic matter after the oxidation experiment. Around 4. 2 Kyr, a significant rise in the number of C4 photosynthesizing plant species has been observed, most likely as a result of increased aridity due to the Meghalayan age drought, which pervaded the Indian subcontinent and beyond.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24..555R/abstract


Revisiting the relationship between the pore water carbon isotope gradient and bottom water oxygen concentrations

Ocean circulation, carbon storage in the deep ocean, and, eventually, the global carbon cycle can be determined by reconstructing the oxygen content at the base of the ocean. Organic carbon degradation in marine sediment by aerobic respiration consumes oxygen in the pore fluid and produces dissolved inorganic carbon. We also show that the calibration of the carbon isotope gradient and bottom water oxygen concentrations must account for the coupled shifts in the carbon system as a result of organic carbon respiration.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.7896B/abstract


Deciphering CH4 emission pathways in a reed ecosystem employing chamber measurements and stable carbon isotope signatures

Due to photosynthetic assimination of carbon dioxide and sequestration of organic matter produced in the Wetland soil or release of sediment-produced methane, the wetlands dominated with common can store carbon. Lake Neusiedl's reed belt and its underlying processes are the second largest reed population in Europe after the Danube delta, with reed and estimation of the various pathways of CH4 emissions in reed belts and their underlying processes that change with the seasons. Lake Neusiedl is Austria's largest lake and Europe's westernmost steppe lake with no natural outflow. The u03b413C-CH4 will be used to identify biological and geological sources of CH4 emissions and to investigate CH4 production and oxidation mechanisms.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.6256A/abstract


A new Berriasian to Coniacian composite carbon isotope record from the Boreal Realm

Here we display upper Berriasian-to-low Coniacian composite carbon isotope record based on 14 drill cores, two outcrops, and nearly 5000 samples. Lower Cretaceous sediments in northern Germany are mainly represented by CaCO3-poor mud- and siltstones of up to 2000 m thickness, which are also chalk-rich during the Albian-Cenomanian transition and even chalkier in the upper Cenomanian to Coniacian period.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.2200B/abstract


Arrayed Arrangement of 13 C Isotopes During the Growth of Inner Single‑Walled Carbon Nanotubes

One wall carbon nanotubes growing in host SWCNTs is a viable alternative to the traditional catalyst-driven growth processes. It not only provides a catalyst-free process, but also the ability to monitor the constituents of the inner tube if appropriate starting molecules are used. colors in black:Semi-empirical results of the Raman modes reveal that this unequivocable result is explicable only if small clusters of ^13 C are assumed. This indicates that there was no carbon diffusion during inner tube expansion.

Source link: https://ui.adsabs.harvard.edu/abs/2017PSSBR.25400217K/abstract


The Priming Effect in Sediments of a Cold Temperate Estuarine System: An Assessment Using Compound Specific Stable Carbon Isotope Ratios Measurements on Bacterial Fatty Acids

The St. Lawrence Estuary and Gulf is the world's largest semi-enclosed estuarine system, rich in natural resources and extremely important in terms of biodiversity, as well as economic, transportation, and recreation activities. Changes in oceanic circulation in the North Atlantic, as well as an increase in the water column flux of organic matter either discharged by the St. Lawrence River and other tributaries or derived in the surface waters from discharged and upwelled nutrients, are fueling hypoxia in this system. The consumption of the more labile OM components of this sedimentation OM by aerobic heterotrophic bacteria has resulted in sustained pressure on dissolved O2 levels and the accumulation of the more recalcitrant portion of this OM. As cold temperate estuarine systems such as the St. Lawrence are characterized by large seasonal shifts in riverine discharge rates and in-site primary production, the more recalcitrant sedimentary OM components's mineralization of the more recalcitrant sedimentary OM components should be strongly influenced by the priming effect, which can be strongly influenced by influxes of fresh and more labile OM components. We'll use a batch incubation strategy in which natural sediments from the St. Lawrence Estuary and Gulf will be amended with fresh terrestrial or marine OM characterized by a highly different 13C/12C ratio. The characterization of oblique OM in this framework, as well as extraction, analysis, and isotopic testing of the bacterial fatty acids will aid in determining the role of labile OM on the mineralization of recalcitrant OM.

Source link: https://ui.adsabs.harvard.edu/abs/2022EGUGA..24.6033R/abstract

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions