Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay
<p>While of higher plant origin, a specific source assignment of sedimentary leaf wax <i>n</i>-alkanes remains difficult. In addition, it is unknown how fast a changing catchment vegetation would be reflected in sedimentary leaf wax archives. In particular, for a quantitative i...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-11-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/14/1607/2018/cp-14-1607-2018.pdf |
| _version_ | 1818577135884828672 |
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| author | B. Aichner F. Ott F. Ott M. Słowiński A. M. Noryśkiewicz A. Brauer D. Sachse |
| author_facet | B. Aichner F. Ott F. Ott M. Słowiński A. M. Noryśkiewicz A. Brauer D. Sachse |
| author_sort | B. Aichner |
| collection | DOAJ |
| description | <p>While of higher plant origin, a specific source assignment of
sedimentary leaf wax <i>n</i>-alkanes remains difficult. In addition, it is
unknown how fast a changing catchment vegetation would be reflected in
sedimentary leaf wax archives. In particular, for a quantitative
interpretation of <i>n</i>-alkane C and H isotope ratios in terms of
paleohydrological and paleoecological changes, a better understanding of
transfer times and dominant sedimentary sources of leaf wax <i>n</i>-alkanes is
required.</p><p>In this study we tested to what extent compositional changes in leaf wax
<i>n</i>-alkanes can be linked to known vegetation changes by comparison with
high-resolution palynological data from the same archive. We analyzed leaf
wax <i>n</i>-alkane concentrations and distributions in decadal resolution from a
sedimentary record from Trzechowskie paleolake (TRZ, northern Poland),
covering the Late Glacial to early Holocene (13 360–9940 yr BP). As
an additional source indicator of targeted <i>n</i>-alkanes, compound-specific carbon
isotopic data have been generated in lower time resolution. The results
indicated rapid responses of <i>n</i>-alkane distribution patterns coinciding with
major climatic and paleoecological transitions. We found a shift towards
higher average chain length (ACL) values at the Allerød–Younger Dryas (YD) transition between 12 680 and 12 600 yr BP, coevaled with a decreasing
contribution of arboreal pollen (mainly <i>Pinus</i> and <i>Betula</i>) and a subsequently higher
abundance of pollen derived from herbaceous plants (Poaceae, Cyperaceae,
<i>Artemisia</i>), shrubs, and dwarf shrubs (<i>Juniperus</i> and <i>Salix</i>). The termination of the YD was
characterized by a successive increase in <i>n</i>-alkane concentrations coinciding
with a sharp decrease in ACL values between 11 580 and 11 490 yr BP,
reflecting the expansion of woodland vegetation at the YD–Holocene
transition. A gradual reversal to longer chain lengths after 11 200 yr BP,
together with decreasing <i>n</i>-alkane concentrations, most likely reflects the
early Holocene vegetation succession with a decline of <i>Betula</i>.</p><p>These results show that <i>n</i>-alkane distributions reflect vegetation changes
and that a fast (i.e., subdecadal) signal transfer occurred. However, our
data also indicate that a standard interpretation of directional changes
in biomarker ratios remains difficult. Instead, responses such as changes in
ACL need to be discussed in the context of other proxy data. In addition, we
find that organic geochemical data integrate different ecological
information compared to pollen, since some gymnosperm genera, such as
<i>Pinus</i>, produce only a very low amount of <i>n</i>-alkanes and for this reason their
contribution may be largely absent from biomarker records. Our results
demonstrate that a combination of palynological and <i>n</i>-alkane data can be used
to infer the major sedimentary leaf wax sources and constrain leaf wax
transport times from the plant source to the sedimentary sink and thus pave
the way towards quantitative interpretation of compound-specific hydrogen
isotope ratios for paleohydrological reconstructions.</p> |
| first_indexed | 2024-12-16T06:25:06Z |
| format | Article |
| id | doaj.art-46869009abdf41e1a5f958d70616c44d |
| institution | Directory Open Access Journal |
| issn | 1814-9324 1814-9332 |
| language | English |
| last_indexed | 2024-12-16T06:25:06Z |
| publishDate | 2018-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Climate of the Past |
| spelling | doaj.art-46869009abdf41e1a5f958d70616c44d2022-12-21T22:41:02ZengCopernicus PublicationsClimate of the Past1814-93241814-93322018-11-01141607162410.5194/cp-14-1607-2018Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delayB. Aichner0F. Ott1F. Ott2M. Słowiński3A. M. Noryśkiewicz4A. Brauer5D. Sachse6Institute of Earth and Environmental Sciences, University of Potsdam, 14476 Potsdam-Golm, GermanySection 5.2: Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyDepartment of Archaeology, Max Planck Institute for the Science of Human History, 07745 Jena, GermanyDepartment of Environmental Resources and Geohazards, Institute of Geography and Spatial Organisation, Polish Academy of Sciences, 00-818 Warsaw, PolandInstitute of Archaeology, Faculty of History, Nicolaus Copernicus University, 87-100 Toruń, PolandSection 5.2: Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyOrganic Surface Geochemistry Lab, Section 5.1: Geomorphology, GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany<p>While of higher plant origin, a specific source assignment of sedimentary leaf wax <i>n</i>-alkanes remains difficult. In addition, it is unknown how fast a changing catchment vegetation would be reflected in sedimentary leaf wax archives. In particular, for a quantitative interpretation of <i>n</i>-alkane C and H isotope ratios in terms of paleohydrological and paleoecological changes, a better understanding of transfer times and dominant sedimentary sources of leaf wax <i>n</i>-alkanes is required.</p><p>In this study we tested to what extent compositional changes in leaf wax <i>n</i>-alkanes can be linked to known vegetation changes by comparison with high-resolution palynological data from the same archive. We analyzed leaf wax <i>n</i>-alkane concentrations and distributions in decadal resolution from a sedimentary record from Trzechowskie paleolake (TRZ, northern Poland), covering the Late Glacial to early Holocene (13 360–9940 yr BP). As an additional source indicator of targeted <i>n</i>-alkanes, compound-specific carbon isotopic data have been generated in lower time resolution. The results indicated rapid responses of <i>n</i>-alkane distribution patterns coinciding with major climatic and paleoecological transitions. We found a shift towards higher average chain length (ACL) values at the Allerød–Younger Dryas (YD) transition between 12 680 and 12 600 yr BP, coevaled with a decreasing contribution of arboreal pollen (mainly <i>Pinus</i> and <i>Betula</i>) and a subsequently higher abundance of pollen derived from herbaceous plants (Poaceae, Cyperaceae, <i>Artemisia</i>), shrubs, and dwarf shrubs (<i>Juniperus</i> and <i>Salix</i>). The termination of the YD was characterized by a successive increase in <i>n</i>-alkane concentrations coinciding with a sharp decrease in ACL values between 11 580 and 11 490 yr BP, reflecting the expansion of woodland vegetation at the YD–Holocene transition. A gradual reversal to longer chain lengths after 11 200 yr BP, together with decreasing <i>n</i>-alkane concentrations, most likely reflects the early Holocene vegetation succession with a decline of <i>Betula</i>.</p><p>These results show that <i>n</i>-alkane distributions reflect vegetation changes and that a fast (i.e., subdecadal) signal transfer occurred. However, our data also indicate that a standard interpretation of directional changes in biomarker ratios remains difficult. Instead, responses such as changes in ACL need to be discussed in the context of other proxy data. In addition, we find that organic geochemical data integrate different ecological information compared to pollen, since some gymnosperm genera, such as <i>Pinus</i>, produce only a very low amount of <i>n</i>-alkanes and for this reason their contribution may be largely absent from biomarker records. Our results demonstrate that a combination of palynological and <i>n</i>-alkane data can be used to infer the major sedimentary leaf wax sources and constrain leaf wax transport times from the plant source to the sedimentary sink and thus pave the way towards quantitative interpretation of compound-specific hydrogen isotope ratios for paleohydrological reconstructions.</p>https://www.clim-past.net/14/1607/2018/cp-14-1607-2018.pdf |
| spellingShingle | B. Aichner F. Ott F. Ott M. Słowiński A. M. Noryśkiewicz A. Brauer D. Sachse Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay Climate of the Past |
| title | Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay |
| title_full | Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay |
| title_fullStr | Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay |
| title_full_unstemmed | Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay |
| title_short | Leaf wax <i>n</i>-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay |
| title_sort | leaf wax i n i alkane distributions record ecological changes during the younger dryas at trzechowskie paleolake northern poland without temporal delay |
| url | https://www.clim-past.net/14/1607/2018/cp-14-1607-2018.pdf |
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