Sea-level driven isolation of glacial plant refugia revealed by submerged lake sediment from the Bering Land Bridge and St. Matthew Island

Arctic Antarctic and Alpine Research
By: , and 

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Abstract

Bering Land Bridge (BLB) climate and vegetation during the Last Glacial Maximum (LGM) remains largely understudied, given challenges associated with collecting records from the submerged BLB. Previous records, confined to the margins of the modern land area and adjacent shelf, reveal conflicting interpretations of Beringian vegetation during the LGM. Here, we reconstruct LGM vegetation, sedimentology, and stable isotopes from a central BLB paleo-lake (Lake Knebel, LK) and compare it with a Holocene peat record from nearby St. Matthew Island (SMI). Results show strong similarities between LGM and late Holocene pollen assemblages, although with differences in relative taxonomic abundance. LGM communities are consistent with a cold and dry steppe or herb tundra environment but suggest the possibility of localized Betula presence in low-lying areas. LK’s bedded lacustrine stratigraphy transitions into undisturbed marine sediments by ~19 ka, providing a maximum limiting age of the transgression. Shrub absence on SMI today and during the Holocene is consistent with island isolation before ~14 to 15 ka, when Betula expanded rapidly at most sites with Bølling-Allerød warming. The combined vegetation evidence indicates preservation of LGM tundra and steppe vegetation assemblages on SMI, suggesting that island vegetation communities may provide additional constraints on the timing of sea level transgression.

Suggested Citation

Jones, M.C., Anderson, L., Caissie, B.E., Harning, D.J., and Ager, T.A., 2025, Sea-level driven isolation of glacial plant refugia revealed by submerged lake sediment from the Bering Land Bridge and St. Matthew Island: Arctic Antarctic and Alpine Research, v. 57, no. 1, 2557062, 21 p., https://doi.org/10.1080/15230430.2025.2557062.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Sea-level driven isolation of glacial plant refugia revealed by submerged lake sediment from the Bering Land Bridge and St. Matthew Island
Series title Arctic Antarctic and Alpine Research
DOI 10.1080/15230430.2025.2557062
Volume 57
Issue 1
Publication Date October 08, 2025
Year Published 2025
Language English
Publisher Taylor and Francis
Contributing office(s) Florence Bascom Geoscience Center
Description 2557062, 21 p.
Country United States
State Alaska
Other Geospatial Bering Land Bridge, St. Matthew Island
Additional publication details