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

2025/10/08 by Miriam C. Jones, Lesleigh Anderson, Beth Caissie +2 · 1 voice · 1 citation
Earth and Planetary Sciences · Environmental Science · #Geology and Paleoclimatology Research #Coastal wetland ecosystem dynamics #Peatlands and Wetlands Ecology

paper · pdf · doi:10.1080/15230430.2025.2557062

openalex publication_date 2025/10/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22

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.

Citations

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Cited by

• Late Quaternary pollen record from southwest Seward Peninsula, western Alaska, and the vegetation history of central Beringia

Discussions

• miriamcjones.bsky.social et al.’s #newarticle on Bering Land Bridge (BLB) climate & vegetation during the Last Glacial Maximum shows Bering Sea island vegetation communities reflect the timing of thei [bsky, 3 points, 0 comments]

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