Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils
Abstract Glacial lake sediments exposed at two sites in Skagit Valley, Washington, encase abundant macrofossils dating from 27.7 to 19.8 cal ka BP. At the last glacial maximum (LGM) most of the valley floor was part of a regionally extensive arid boreal (subalpine) forest that periodically included...
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Cambridge University Press (CUP)
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crcambridgeupr:10.1017/qua.2021.50 2024-09-30T14:34:14+00:00 Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils Riedel, Jon L. Telka, Alice Bunn, Andy Clague, John J. 2021 http://dx.doi.org/10.1017/qua.2021.50 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589421000508 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 106, page 94-112 ISSN 0033-5894 1096-0287 journal-article 2021 crcambridgeupr https://doi.org/10.1017/qua.2021.50 2024-09-18T04:03:44Z Abstract Glacial lake sediments exposed at two sites in Skagit Valley, Washington, encase abundant macrofossils dating from 27.7 to 19.8 cal ka BP. At the last glacial maximum (LGM) most of the valley floor was part of a regionally extensive arid boreal (subalpine) forest that periodically included montane and temperate trees and open boreal species such as dwarf birch, northern spikemoss, and heath. We used the modern distribution and climate of 14 species in 12 macrofossil assemblages and a probability density function approach to reconstruct the LGM climate. Median annual precipitation (MAP) at glacial Lake Concrete (GLC) was ~50% lower than today. In comparison, MAP at glacial Lake Skymo (GLS) was only ~10% lower, which eliminated the steep climate gradient observed today. Median January air temperature at GLC was up to 10.8°C lower than today at 23.5 cal ka BP and 8.7°C lower at GLS at 25.1 cal ka BP. Median July air temperature declines were smaller at GLC (3.4°C–5.0°C) and GLS (4.2°C–6.3°C). Warmer winters (+2°C to +4°C) and increases in MAP (+200 mm) occurred at 27.7, 25.9, 24.4, and 21.2–20.7 cal ka BP. These changes accord with other regional proxies and Dansgaard–Oeschger interstades in the North Atlantic. Article in Journal/Newspaper Dwarf birch North Atlantic Cambridge University Press Glacial Lake ENVELOPE(-129.463,-129.463,58.259,58.259) Quaternary Research 1 19 |
institution |
Open Polar |
collection |
Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Glacial lake sediments exposed at two sites in Skagit Valley, Washington, encase abundant macrofossils dating from 27.7 to 19.8 cal ka BP. At the last glacial maximum (LGM) most of the valley floor was part of a regionally extensive arid boreal (subalpine) forest that periodically included montane and temperate trees and open boreal species such as dwarf birch, northern spikemoss, and heath. We used the modern distribution and climate of 14 species in 12 macrofossil assemblages and a probability density function approach to reconstruct the LGM climate. Median annual precipitation (MAP) at glacial Lake Concrete (GLC) was ~50% lower than today. In comparison, MAP at glacial Lake Skymo (GLS) was only ~10% lower, which eliminated the steep climate gradient observed today. Median January air temperature at GLC was up to 10.8°C lower than today at 23.5 cal ka BP and 8.7°C lower at GLS at 25.1 cal ka BP. Median July air temperature declines were smaller at GLC (3.4°C–5.0°C) and GLS (4.2°C–6.3°C). Warmer winters (+2°C to +4°C) and increases in MAP (+200 mm) occurred at 27.7, 25.9, 24.4, and 21.2–20.7 cal ka BP. These changes accord with other regional proxies and Dansgaard–Oeschger interstades in the North Atlantic. |
format |
Article in Journal/Newspaper |
author |
Riedel, Jon L. Telka, Alice Bunn, Andy Clague, John J. |
spellingShingle |
Riedel, Jon L. Telka, Alice Bunn, Andy Clague, John J. Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
author_facet |
Riedel, Jon L. Telka, Alice Bunn, Andy Clague, John J. |
author_sort |
Riedel, Jon L. |
title |
Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
title_short |
Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
title_full |
Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
title_fullStr |
Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
title_full_unstemmed |
Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
title_sort |
reconstruction of climate and ecology of skagit valley, washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils |
publisher |
Cambridge University Press (CUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1017/qua.2021.50 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589421000508 |
long_lat |
ENVELOPE(-129.463,-129.463,58.259,58.259) |
geographic |
Glacial Lake |
geographic_facet |
Glacial Lake |
genre |
Dwarf birch North Atlantic |
genre_facet |
Dwarf birch North Atlantic |
op_source |
Quaternary Research volume 106, page 94-112 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/qua.2021.50 |
container_title |
Quaternary Research |
container_start_page |
1 |
op_container_end_page |
19 |
_version_ |
1811637915193704448 |