scholarly journals Carbon Uptake in Aquatic Plants Deduced From Their Natural 13C and 14C Content

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 785-794 ◽  
Author(s):  
Elena Marčenko ◽  
Dušan Srdoč ◽  
Stjepko Golubić ◽  
Jože Pezdič ◽  
M J Head
Keyword(s):  
Carbon Source ◽  
Aquatic Plants ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Natural Habitat ◽  
Terrestrial Plants ◽  
Activity Measurements ◽  
Aquatic Mosses ◽  
Age Correction ◽  
Karst Waters

δ13C and 14C activity measurements were made on terrestrial, marsh and aquatic plants growing in their natural habitat of the Plitvice Lakes in northwest Yugoslavia. δ13C values were ca −47 for aquatic mosses, which indicate that the carbon source was dissolved inorganic carbon (DIC) from alkaline karst waters, following a C3 pathway, and ca −25 for marsh plants, indicating the carbon source was atmospheric CO2. 14C activity of true aquatic plants and submerged parts of helophytes was close to 14C activity of DIC, whereas that of emergent parts of helophytes and terrestrial plants was similar to atmospheric CO2 activity. Aquatic plants which use DIC in freshwater for their photosynthesis are not suitable for 14C dating, unless the initial activity of incorporated carbon is known. δ13C values of plant material also depend on the carbon source and cannot be used for 14C age correction.

scholarly journals Increase of 14C Activity of Dissolved Inorganic Carbon Along a River Course

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 515-521 ◽  
Author(s):  
Dušan Srdoč ◽  
Ines Krajcar-Bronić ◽  
Nada Horvatinčić ◽  
Bogomil Obelić
Keyword(s):  
Aquatic Plants ◽  
Water Samples ◽  
Organic Material ◽  
Root Respiration ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Exchange Process ◽  
Karst Spring ◽  
Stream Waters

Results of measurements for 3 years (1981–1983) of 14C activity of dissolved inorganic carbon (DIG) in water samples from the Korana River, as well as that of recent tufa and aquatic plants, showed that 14C concentration increases from karst spring to the estuary. A model describing the increase of 14C activity was developed assuming that the increase is due to the exchange of the dissolved CO2 in stream water with atmospheric CO2 and to dissolution of CO2 from the decay of organic material and root respiration. It is possible to distinguish these two contributions by measuring the δ13C values of DIC in water. As expected, our data show that the exchange process between atmospheric CO2 and DIC dominates at rapids and waterfalls, while biologic contribution is much higher in lakes and along the lowland flow of the Korana River. Agreement between the calculated and the measured activities supports the proposed mechanisms of chemical and isotopic exchanges in stream waters.

scholarly journals Radiocarbon isotopic evidence for assimilation of atmospheric CO<sub>2</sub> by the seagrass <i>Zostera marina</i>

2015 ◽  
Vol 12 (20) ◽  
pp. 6251-6258 ◽  
Author(s):  
K. Watanabe ◽  
T. Kuwae
Keyword(s):  
Carbon Source ◽  
Zostera Marina ◽  
Inorganic Carbon ◽  
Aquatic Vegetation ◽  
Dissolved Inorganic Carbon ◽  
Isotope Analysis ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
Isotopic Signatures ◽  
Seagrass Meadows

Abstract. Submerged aquatic vegetation takes up water-column dissolved inorganic carbon (DIC) as a carbon source across its thin cuticle layer. It is expected that marine macrophytes also use atmospheric CO2 when exposed to air during low tide, although assimilation of atmospheric CO2 has never been quantitatively evaluated. Using the radiocarbon isotopic signatures (Δ14C) of the seagrass Zostera marina, DIC and particulate organic carbon (POC), we show quantitatively that Z. marina takes up and assimilates atmospheric modern CO2 in a shallow coastal ecosystem. The Δ14C values of the seagrass (−40 to −10 ‰) were significantly higher than those of aquatic DIC (−46 to −18 ‰), indicating that the seagrass uses a 14C-rich carbon source (atmospheric CO2, +17 ‰). A carbon-source mixing model indicated that the seagrass assimilated 0–40 % (mean, 17 %) of its inorganic carbon as atmospheric CO2. CO2 exchange between the air and the seagrass might be enhanced by the presence of a very thin film of water over the air-exposed leaves during low tide. Our radiocarbon isotope analysis, showing assimilation of atmospheric modern CO2 as an inorganic carbon source, improves our understanding of the role of seagrass meadows in coastal carbon dynamics.

Carbon isotopes in dissolved inorganic carbon as tracers of carbon sources in karst waters of the Plitvice Lakes, Croatia

2020 ◽  
pp. SP507-2020-49 ◽  
Author(s):  
Andreja Sironić ◽  
Ines Krajcar Bronić ◽  
Nada Horvatinčić ◽  
Jadranka Barešić ◽  
Damir Borković ◽  
...  
Keyword(s):  
Carbon Isotopes ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Carbon Sources ◽  
Karst Waters ◽  
Plitvice Lakes

scholarly journals Radiocarbon Concentration and Origin of Thermal Karst Waters in the Region of the Bükk Mountains, Northeastern Hungary

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 543-550 ◽  
Author(s):  
Ede Hertelendi ◽  
Mihály Veres ◽  
István Futó ◽  
Éva Svingor ◽  
Lajos Mikó ◽  
...  
Keyword(s):  
Thermal Water ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Karst Aquifer ◽  
Thermal Waters ◽  
Karst Water ◽  
Recharge Area ◽  
Karst Springs ◽  
Karst Waters ◽  
Karst Systems

Karst springs are abundant in Hungary, and many are thermal (temperatures >30°). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and δ18O in the water and δ13C and 14C in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bükk Mountains, northeastern Hungary. Environmental isotope data confirm the karst water-flow pattern implied by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The 14C activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2 contributes to the 14C activity of these groundwaters. We observed good correlation between 14C and 3H activities and we determined negative correlations between 14C concentration and δ13C values and temperature. From the δ18O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present.

scholarly journals Radiocarbon isotopic evidence for assimilation of atmospheric CO<sub>2</sub> by the seagrass </i>Zostera marina</i>

2015 ◽  
Vol 12 (10) ◽  
pp. 7599-7611
Author(s):  
K. Watanabe ◽  
T. Kuwae
Keyword(s):  
Carbon Source ◽  
Zostera Marina ◽  
Inorganic Carbon ◽  
Aquatic Vegetation ◽  
Dissolved Inorganic Carbon ◽  
Isotope Analysis ◽  
Water Film ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
Seagrass Meadows

Abstract. Submerged aquatic vegetation assimilates dissolved inorganic carbon (DIC) in the water column as a carbon source across its thin cuticle layer. However, it is expected that marine macrophytes also use atmospheric CO2 when exposed to the air during low tide, although assimilation of atmospheric CO2 has never been quantitatively evaluated. Using the radiocarbon isotopic signatures (Δ14C) of the seagrass Zostera marina and DIC, we show quantitatively that Z. marina takes up and assimilates atmospheric modern CO2 in a shallow coastal ecosystem. The Δ14C values of the seagrass (−36 to −8‰) were significantly higher than those of aquatic DIC (−45 to −18‰), indicating that the seagrass uses a 14C-rich carbon source (atmospheric CO2, +17‰). A carbon-source mixing model indicated that the seagrass assimilated ~ 46% (mean: 22%) of its inorganic carbon as atmospheric CO2. CO2 exchange between the air and the seagrass may be enhanced by the presence of a very thin water film over the air-exposed leaves during low tide. Our radiocarbon isotope analysis, showing assimilation of atmospheric modern CO2 as an inorganic carbon source, offers better understanding of the role of seagrass meadows in coastal carbon dynamics.

scholarly journals Sources of Radon Contamination in 14C Dating

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 749-757 ◽  
Author(s):  
Nada Horvatinčić ◽  
Bogomil Obelić ◽  
Ines Krajcar Bronić ◽  
Dušan Srdoč ◽  
Romana Bistrović
Keyword(s):  
Aquatic Plants ◽  
Proportional Counter ◽  
Count Rate ◽  
Dissolved Inorganic Carbon ◽  
Catalytic Reduction ◽  
Organic Soil ◽  
Wood Charcoal ◽  
Gas Purification ◽  
14C Dating ◽  
Activity Measurements

We investigated the effect of radon (222Rn) contamination of samples and chemicals used for sample preparation and gas purification on the 14C age of samples. Radon count rate was monitored over several 222Rn half-lives in a proportional counter filled with methane. We analyzed ca. 240 samples of fossil and recent wood, charcoal, bone, dissolved inorganic carbon in water, travertine, peat, aquatic plants, organic soil and atmospheric CO2 for 222Rn contamination. Chemicals used for gas purification (MnO2, Mg(ClO4)2), ruthenium-coated pellets used for catalytic reduction of CO2 to CH4, and acids used for dissolution of calcareous samples (HCl and H3PO4) are also potential sources of Rn. Most geological samples contained a significant amount of Rn, as opposed to samples of wood, charcoal, aquatic plants and atmospheric CO2. We also studied Rn contamination of water samples during tritium activity measurements in a CH4-filled gas proportional counter. We found an increased count rate in the 3H channel, as well as above the 20 keV region in Rn-contaminated groundwater samples.

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