Rapid climate changes during the Lateglacial and the early Holocene as seen from plant community dynamics in the Polar Urals, Russia

Abstract

A detailed, well‐dated record of pollen and sedimentary ancient DNA (sedaDNA) for the period 15 000–9500 cal a bp describes changes at Lake Bolshoye Shchuchye in the Polar Ural Mountains, located far east of the classical Lateglacial sites in western Europe. Arctic tundra rapidly changed to lusher vegetation, possibly including both dwarf (Betula nana) and tree birch (B. pubescens), dated in our record to take place 14 565 cal a bp, coincident with the onset of the Bølling in western Europe; this was paralleled by increased summer temperatures. A striking feature is an early decline in Betula pollen and sedaDNA reads 300 years before the onset of the Younger Dryas (YD) in western Europe. Given the solid site chronology, this could indicate that the YD cooling started in Siberia and propagated westwards, or that the vegetation reacted to the inter‐Allerød cooling at 13 100 cal a bp and did not recover during the late Allerød. During the YD, increases in steppe taxa such as Artemisia and Chenopodiaceae suggest drier conditions. At the onset of the Holocene, the vegetation around the lake reacted fast to the warmer conditions, as seen in the increase of arboreal taxa, especially Betula, and a decrease in herbs such as Artemisia and Cyperaceae.

High‐resolution chronology of 24 000‐year long cores from two lakes in the Polar Urals, Russia, correlated with palaeomagnetic inclination records with a distinct event about 20 000 years ago

“…This improved age model of core 506‐48 has been applied in the companion papers by Bjune et al . (2021) and by Cowling et al . (2021) and will be used in future papers on this lake.…”

Quaternary environmental and climatic history of the northern high latitudes – recent contributions and perspectives from lake sediment records

“…From the core from Lake Bolshoye Shchuchye, Cowling et al (2022) reconstructed the regional development of vegetation, precipitation and temperature, based on analyses of the pollen assemblages, element concentrations and δ 2 H ratios of leaf waxes. Additional analyses of SedaDNA in the central part of the core, conducted by Bjune et al (2022), provide more detailed information on vegetation and climate changes during the period from 15 to 9 ka BP. A new 54 m long core recovered in 2016 from the centre of Lake Bolshoye Shchuchye extends the record to 27 ka BP, according to radiocarbon, luminescence, varve, pollen and palaeomagnetic dating (Lenz et al 2022a).…”

“…Additional analyses of Seda DNA in the central part of the core, conducted by Bjune et al . (2022), provide more detailed information on vegetation and climate changes during the period from 15 to 9 ka bp. A new 54 m long core recovered in 2016 from the centre of Lake Bolshoye Shchuchye extends the record to 27 ka bp , according to radiocarbon, luminescence, varve, pollen and palaeomagnetic dating (Lenz et al .…”

Improving age-depth correlations by using the LANDO model ensemble

“…First, we considered the 11 700-yr BP (Before Present, i.e., before 1950 CE) boundary as our marker for the change between Holocene and Pleistocene to separate the datasets (Rasmussen et al, 2006;Lowe and Walker, 2014;295 Walker et al, 2008). We selected this marker because numerous studies suggest a general difference in sedimentation regimes between these periods (e.g., Brosius et al, 2021;Vyse et al, 2021;Baumer et al, 2021;Bjune et al, 2021;Kublitskiy et al, 2020;Müller et al, 2009;Wolfe, 1996). As some of the models were below the 11 700-yr BP marker, the calculation of the mean sedimentation rate for the Pleistocene featured only a subset of sediment cores (total number of sediment cores with measurement in Pleistocene: 20).…”