Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C
To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (dD)...
Published in: | Quaternary Science Reviews |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
PERGAMON-ELSEVIER SCIENCE LTD
2010
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/25275/ https://doi.org/10.1016/j.quascirev.2010.06.039 https://hdl.handle.net/10013/epic.39163 |
id |
ftawi:oai:epic.awi.de:25275 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:25275 2023-05-15T17:35:20+02:00 Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, S. Mollenhauer, Gesine Schulz, Michael Wefer, Gerold 2010 https://epic.awi.de/id/eprint/25275/ https://doi.org/10.1016/j.quascirev.2010.06.039 https://hdl.handle.net/10013/epic.39163 unknown PERGAMON-ELSEVIER SCIENCE LTD Niedermeyer, E. M. , Schefuß, E. , Sessions, A. L. , Mulitza, S. , Mollenhauer, G. orcid:0000-0001-5138-564X , Schulz, M. and Wefer, G. (2010) Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C , Quaternary Science Reviews, 29 (23-24), pp. 2996-3005 . doi:10.1016/j.quascirev.2010.06.039 <https://doi.org/10.1016/j.quascirev.2010.06.039> , hdl:10013/epic.39163 EPIC3Quaternary Science Reviews, PERGAMON-ELSEVIER SCIENCE LTD, 29(23-24), pp. 2996-3005, ISSN: 0277-3791 Article isiRev 2010 ftawi https://doi.org/10.1016/j.quascirev.2010.06.039 2021-12-24T15:35:22Z To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (dD) of individual terrestrial plant wax n-alkanes as a proxy for past rainfall variability. The abundance and stable carbon isotopic composition (d13C) of the same compounds were analyzed to assess changes in vegetation composition (C3/C4 plants) and density. The dD record reveals two wet periods that coincide with local maximum summer insolation from 38 to 28 ka and 15 to 4 ka and that are separated by a less wet period during minimum summer insolation. Our data indicate that rainfall intensity during the rainy season throughout both wet humid periods was similar, whereas the length of the rainy season was presumably shorter during the last glacial than during the Holocene. Additional dry intervals are identified that coincide with North Atlantic Heinrich stadials and the Younger Dryas interval, indicating that the West African monsoon over tropical northwest Africa is linked to both insolation forcing and highlatitude climate variability. The d13C record indicates that vegetation of the western Sahel was consistently dominated by C4 plants during the past 44 ka, whereas C3-type vegetation increased during the Holocene. Moreover, we observe a gradual ending of the Holocene humid period together with unchanging ratio of C3 to C4 plants, indicating that an abrupt aridification due to vegetation feedbacks is not a general characteristic of this time interval. Article in Journal/Newspaper North Atlantic Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Quaternary Science Reviews 29 23-24 2996 3005 |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (dD) of individual terrestrial plant wax n-alkanes as a proxy for past rainfall variability. The abundance and stable carbon isotopic composition (d13C) of the same compounds were analyzed to assess changes in vegetation composition (C3/C4 plants) and density. The dD record reveals two wet periods that coincide with local maximum summer insolation from 38 to 28 ka and 15 to 4 ka and that are separated by a less wet period during minimum summer insolation. Our data indicate that rainfall intensity during the rainy season throughout both wet humid periods was similar, whereas the length of the rainy season was presumably shorter during the last glacial than during the Holocene. Additional dry intervals are identified that coincide with North Atlantic Heinrich stadials and the Younger Dryas interval, indicating that the West African monsoon over tropical northwest Africa is linked to both insolation forcing and highlatitude climate variability. The d13C record indicates that vegetation of the western Sahel was consistently dominated by C4 plants during the past 44 ka, whereas C3-type vegetation increased during the Holocene. Moreover, we observe a gradual ending of the Holocene humid period together with unchanging ratio of C3 to C4 plants, indicating that an abrupt aridification due to vegetation feedbacks is not a general characteristic of this time interval. |
format |
Article in Journal/Newspaper |
author |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, S. Mollenhauer, Gesine Schulz, Michael Wefer, Gerold |
spellingShingle |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, S. Mollenhauer, Gesine Schulz, Michael Wefer, Gerold Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
author_facet |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, S. Mollenhauer, Gesine Schulz, Michael Wefer, Gerold |
author_sort |
Niedermeyer, Eva M. |
title |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
title_short |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
title_full |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
title_fullStr |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
title_full_unstemmed |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C |
title_sort |
orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western african sahel: insights from individual plant wax dd and d13c |
publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
publishDate |
2010 |
url |
https://epic.awi.de/id/eprint/25275/ https://doi.org/10.1016/j.quascirev.2010.06.039 https://hdl.handle.net/10013/epic.39163 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
EPIC3Quaternary Science Reviews, PERGAMON-ELSEVIER SCIENCE LTD, 29(23-24), pp. 2996-3005, ISSN: 0277-3791 |
op_relation |
Niedermeyer, E. M. , Schefuß, E. , Sessions, A. L. , Mulitza, S. , Mollenhauer, G. orcid:0000-0001-5138-564X , Schulz, M. and Wefer, G. (2010) Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax dD and d13C , Quaternary Science Reviews, 29 (23-24), pp. 2996-3005 . doi:10.1016/j.quascirev.2010.06.039 <https://doi.org/10.1016/j.quascirev.2010.06.039> , hdl:10013/epic.39163 |
op_doi |
https://doi.org/10.1016/j.quascirev.2010.06.039 |
container_title |
Quaternary Science Reviews |
container_volume |
29 |
container_issue |
23-24 |
container_start_page |
2996 |
op_container_end_page |
3005 |
_version_ |
1766134460639608832 |