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Titel |
Factors controlling shell carbon isotopic composition of land snail Acusta despecta sieboldiana estimated from laboratory culturing experiment |
VerfasserIn |
N. Zhang, K. Yamada, N. Suzuki, N. Yoshida |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 11, no. 19 ; Nr. 11, no. 19 (2014-10-06), S.5335-5348 |
Datensatznummer |
250117621
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Publikation (Nr.) |
copernicus.org/bg-11-5335-2014.pdf |
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Zusammenfassung |
The carbon isotopic composition (δ13C) of land snail shell
carbonate derives from three potential sources: diet, atmospheric CO2,
and ingested carbonate (limestone). However, their relative contributions
remain unclear. Under various environmental conditions, we cultured one land
snail subspecies, Acusta despecta sieboldiana, collected from Yokohama, Japan, and confirmed that all of
these sources affect shell carbonate δ13C values. Herein, we
consider the influences of metabolic rates and temperature on the carbon
isotopic composition of the shell carbonate. Based on results obtained from
previous works and this study, a simple but credible framework is presented
to illustrate how each source and environmental parameter affects shell
carbonate δ13C values. According to this framework and some
reasonable assumptions, we estimated the contributions of different carbon
sources for each snail individual: for cabbage-fed (C3 plant) groups,
the contributions of diet, atmospheric CO2, and ingested limestone vary in the ranges of 66–80, 16–24, and 0–13%, respectively. For corn-fed (C4 plant) groups, because of the possible food stress (less ability to consume
C4 plants), the values vary in the ranges of 56–64,
18–20, and 16–26%, respectively. Moreover, according to the literature and our
observations, the subspecies we cultured in this study show preferences towards different plant species for food. Therefore, we suggest that the
potential food preference should be considered adequately for some species
in paleoenvironment studies. Finally, we inferred that only the isotopic
exchange of the calcite-HCO3−-aragonite equilibrium during
egg laying and hatching of our cultured snails controls carbon isotope
fractionation. |
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