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Titel |
Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania) |
VerfasserIn |
J. Holtvoeth, H. Vogel, B. Wagner, G. A. Wolff |
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 ; 7, no. 11 ; Nr. 7, no. 11 (2010-11-08), S.3473-3489 |
Datensatznummer |
250005052
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Publikation (Nr.) |
copernicus.org/bg-7-3473-2010.pdf |
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Zusammenfassung |
Organic matter preserved in Lake Ohrid sediments originates from aquatic and
terrestrial sources. Its variable composition reflects climate-controlled
changes in the lake basin's hydrology and related organic matter export,
i.e. changes in primary productivity, terrestrial plant matter input and
soil erosion. Here, we present first results from lipid biomarker
investigations of Lake Ohrid sediments from two near-shore settings: site
Lz1120 near the southern shore, with low-lying lands nearby and probably
influenced by river discharge, and site Co1202 which is close to the steep
eastern slopes. Variable proportions of terrestrial n-alkanoic acids and
n-alkanols as well as compositional changes of ω-hydroxy acids
document differences in soil organic matter supply between the sites and
during different climate stages (glacial, Holocene, 8.2 ka cooling event).
Changes in the vegetation cover are suggested by changes in the dominant
chain length of terrestrial n-alkanols. Effective microbial degradation of
labile organic matter and in situ contribution of organic matter derived
from the microbes themselves are both evident in the sediments. We found
evidence for anoxic conditions within the photic zone by detecting
epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria
and bacterivorous ciliates and for the influence of a settled human
community from the occurrence of coprostanol, a biomarker for human and
animal faeces (pigs, sheep, goats), in an early Holocene sample. This study
illustrates the potential of lipid biomarkers for future environmental
reconstructions using one of Europe's oldest continental climate archives,
Lake Ohrid. |
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