scholarly journals Distribution and Sources of Organic Carbon in Surface Intertidal Sediments of the Rudong Coast, Jiangsu Province, China

2021 ◽  
Vol 9 (9) ◽  
pp. 992
Author(s):  
Yinan Mao ◽  
Qingyun Ma ◽  
Jiaxin Lin ◽  
Ye Chen ◽  
Qiang Shu
Keyword(s):  
Organic Carbon ◽  
Tidal Flat ◽  
Stable Carbon Isotopes ◽  
Mixing Model ◽  
Depositional Environments ◽  
Stable Carbon ◽  
Intertidal Sediments ◽  
Δ13c Value ◽  
The Mean ◽  
Tidal Flat Sediments

In this study, total organic carbon (TOC), total nitrogen (TN), and stable carbon isotopes (δ13C) were measured in surface intertidal saltmarsh and bare tidal flat sediments along the Rudong coast. The distribution and sources of organic carbon were examined under different depositional environments based on C/N ratios and a two-terminal mixing model. The results showed that the average TOC content of the vegetated saltmarsh sediments, bare tidal flat areas near vegetation (BF1), and bare tidal flat areas far from vegetation (BF2) were 4.05, 2.72, and 1.22 mg/g, respectively. The mean δ13C value within the vegetated saltmarsh area was −22.37‰, and the C/N ratio was 9.3; the corresponding values in the BF1 area were −23.27‰ and 7.95, respectively; and in the BF2 area, the corresponding values were −21.91‰ and 5.36, respectively. These C/N ratios reflect an increasing marine contribution with distance from the vegetated zone. Combined with the two-terminal mixing model, the organic carbon in the vegetated saltmarsh sediments was dominated by terrestrial sources, while the bare tidal flat sediments were more influenced by marine sources, and the bare tidal flat sediments nearer to the vegetated zone (BF1) were influenced by a combination of vegetation, marine sources, and other terrestrial factors.

Combined use of radiocarbon and stable carbon isotopes for the source mixing model in a stream food web

2020 ◽  
Vol 65 (11) ◽  
pp. 2688-2696
Author(s):  
Naoto F. Ishikawa ◽  
Jacques C. Finlay ◽  
Hiromi Uno ◽  
Nanako O. Ogawa ◽  
Naohiko Ohkouchi ◽  
...  
Keyword(s):  
Food Web ◽  
Carbon Isotopes ◽  
Stable Carbon Isotopes ◽  
Mixing Model ◽  
Stable Carbon ◽  
Combined Use

scholarly journals Climatic variations during the Holocene inferred from radiocarbon and stable carbon isotopes in a high-alpine cave

2021 ◽  
Author(s):  
Caroline Welte ◽  
Jens Fohlmeister ◽  
Melina Wertnik ◽  
Lukas Wacker ◽  
Bodo Hattendorf ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Stable Carbon Isotopes ◽  
Stable Carbon Isotope ◽  
Climatic Conditions ◽  
Stable Carbon ◽  
Novel Technique ◽  
Climatic Variations ◽  
Spatially Resolved ◽  
Exchange Processes ◽  
Carbon Reservoir

<div> <p>Laser ablation coupled online to accelerator mass spectrometry [1] allows analyzing the radiocarbon (<sup>14</sup>C) concentration in carbonate samples in a fast and spatially resolved manner. This novel technique can provide <sup>14</sup>C data at a spatial resolution comparable to that of stable carbon isotope measurements and, thus, can help to interpret δ<sup>13</sup>C signatures. In this work, we analyzed δ<sup>13</sup>C and <sup>14</sup>C of a Holocene stalagmite from the high-alpine Spannagel Cave (Austria). Combined δ<sup>13</sup>C and <sup>14</sup>C profiles allow identifying three growth periods : (i) the period > 8 ka BP exhibits relatively low δ<sup>13</sup>C values with small variability combined with a comparably high dead carbon fraction (dcf) of around 60%. This points towards C contributions of an old organic carbon reservoir in the karst potentially mobilized due to the warm climatic conditions of the early Holocene. (ii) Between 3.8 and 8 ka BP, a strong variability in δ<sup>13</sup>C with values from -8 to +1‰ and a generally lower dcf was observed. The δ<sup>13</sup>C variability was most likely caused by changes in gas exchange processes in the cave, which are induced by reduced drip rates as derived from lower stalagmite growth rates. Additionally, the lower dcf indicates that the OM reservoir contributed less to stalagmite growth in this period possibly as a result of reduced precipitation or because the OM reservoir became exhausted. (iii) In the youngest section between 2.4 and 3.8 ka BP, comparably stable and low δ<sup>13</sup>C values combined with an increasing dcf reaching up to 50% are again hinting towards a contribution of an aged organic carbon reservoir in the karst.</p> </div><p>[1] C. Welte, et al., (2016). Anal. Chem., 88, 8570– 8576.</p>

scholarly journals Radiocarbon and Stable Carbon Isotopes in Two Soil Profiles from Northeast India

Radiocarbon ◽  
2012 ◽  
Vol 54 (01) ◽  
pp. 81-89 ◽  
Author(s):  
Amzad H Laskar ◽  
M G Yadava ◽  
R Ramesh
Keyword(s):  
Organic Carbon ◽  
Stable Carbon Isotopes ◽  
Agricultural Land ◽  
Clay Content ◽  
Carbon Dynamics ◽  
Northeast India ◽  
Turnover Time ◽  
Soil Profiles ◽  
The Mean ◽  
Surface Vegetation

Two soil profiles from northeast India, one from Bakrihawar, an agricultural land, and the other from Chandipur, a virgin hilly area from Assam, are investigated to understand the organic carbon dynamics of the area. Due to frequent flooding, the Bakrihawar soil has accumulated a higher clay content than that of Chandipur. The carbon content is less than 1% by weight in both the sites. The higher clay content is responsible for relatively more soil organic carbon at Bakrihawar. The mean δ13C values at both sites reflect the values of the overlying vegetation. At Bakrihawar, both rice cultivation (C3) and natural C4grasses contribute to higher mean enriched values of13C relative to Chandipur, where the surface vegetation is mostly of C3type. The turnover time of organic carbon, estimated using the residual radiocarbon content, depends strongly on the soil particle size distribution, especially the clay content (i.e. it increases with clay content). To the best of our knowledge, this is the first soil carbon dynamics study of its kind from northeast India.

Stable-carbon isotopes and soil organic carbon in wheat under CO2 enrichment

2001 ◽  
Vol 150 (2) ◽  
pp. 305-314 ◽  
Author(s):  
S. W. Leavitt ◽  
E. Pendall ◽  
E. A. Paul ◽  
T. Brooks ◽  
B. A. Kimball ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Isotopes ◽  
Stable Carbon Isotopes ◽  
Co2 Enrichment ◽  
Stable Carbon

scholarly journals Radiocarbon and Stable Carbon Isotopes in Two Soil Profiles from Northeast India

Radiocarbon ◽  
2012 ◽  
Vol 54 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Amzad H Laskar ◽  
M G Yadava ◽  
R Ramesh
Keyword(s):  
Organic Carbon ◽  
Stable Carbon Isotopes ◽  
Agricultural Land ◽  
Clay Content ◽  
Carbon Dynamics ◽  
Northeast India ◽  
Turnover Time ◽  
Soil Profiles ◽  
The Mean ◽  
Surface Vegetation

Two soil profiles from northeast India, one from Bakrihawar, an agricultural land, and the other from Chandipur, a virgin hilly area from Assam, are investigated to understand the organic carbon dynamics of the area. Due to frequent flooding, the Bakrihawar soil has accumulated a higher clay content than that of Chandipur. The carbon content is less than 1% by weight in both the sites. The higher clay content is responsible for relatively more soil organic carbon at Bakrihawar. The mean δ13C values at both sites reflect the values of the overlying vegetation. At Bakrihawar, both rice cultivation (C3) and natural C4 grasses contribute to higher mean enriched values of 13C relative to Chandipur, where the surface vegetation is mostly of C3 type. The turnover time of organic carbon, estimated using the residual radiocarbon content, depends strongly on the soil particle size distribution, especially the clay content (i.e. it increases with clay content). To the best of our knowledge, this is the first soil carbon dynamics study of its kind from northeast India.

What fraction of the organic carbon in sacoglossans is obtained from photosynthesis by kleptoplastids? An investigation using the natural abundance of stable carbon isotopes

2001 ◽  
Vol 138 (3) ◽  
pp. 537-545 ◽  
Author(s):  
J. A. Raven ◽  
D. I. Walker ◽  
K. R. Jensen ◽  
L. L. Handley ◽  
C. M. Scrimgeour ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Isotopes ◽  
Stable Carbon Isotopes ◽  
Natural Abundance ◽  
Stable Carbon
Sign in / Sign up

Export Citation Format

Share Document