| Autor: |
Schilder, Jos, Bastviken, David, van Hardenbroek, Maarten, Leuenberger, Markus, Rinta, Päivi, Stötter, Tabea, Heiri, Oliver |
| Předmět: |
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| Zdroj: |
Limnology & Oceanography; May2015, Vol. 60 Issue 3, p1064-1075, 12p |
| Abstrakt: |
Daphnia can ingest methane-oxidizing bacteria and incorporate methanogenic carbon into their biomass, leading to low stable carbon isotope ratios (expressed as δ13C values) of their tissue. Therefore, δ13C analysis of Daphnia resting eggs (ephippia) in lake sediment records can potentially be used to reconstruct past in-lake availability of methane (CH4). However, detailed multilake studies demonstrating that δ13C values of recently deposited Daphnia ephippia ( δ13Cephippia) are systematically related to in-lake CH4 concentrations ([CH4]aq) are still missing. We measured δ13Cephippia from surface sediments of 15 small lakes in Europe, and compared these values with late-summer [CH4]aq. δ13Cephippia ranged from −51.6‰ to −25.9‰, and was strongly correlated with [CH4]aq in the surface water and above the sediment ( r −0.73 and −0.77, respectively), whereas a negative rather than the expected positive correlation was found with δ13C values of carbon dioxide (CO2) ( r −0.54), and no correlation was observed with [CO2]aq. At eight sites, offsets between δ13 [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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