Vegetation and climate during the penultimate interglacial of the northeastern Russian Arctic: the Lake El'gygytgyn pollen record

Abstract

We present a high‐resolution reconstruction of the vegetation and climate dynamics during the penultimate interglacial, corresponding with Marine Isotope Stage (MIS) 7, based on detailed palynological analyses of lacustrine sediments from Lake El'gygytgyn, northeastern Siberia. The analysed sediments were deposited between 246 and 181 ka ago (late MIS 8 to early MIS 6.6). The interglacial vegetation was characterized by herb and shrub (mainly alder and birch) dominated plant communities. Pollen‐based biome reconstruction shows a dominance of the tundra (TUND) biome, thus indicating rather open vegetation. Warmer intervals (MIS 7.5, 7.3 and 7.1) were marked by an increase in the cold deciduous forest (CLDE) biome scores and a synchronous decrease in the cold steppe (STEP) biome scores. The thermal maximum occurred during MIS 7.1, as indicated by the highest CLDE biome scores occurring in this period, and lasted ~10 ka, possibly favoured by the high precession‐related summer insolation and the legacy of the preceding mild and dry stadial (MIS 7.2). In contrast, MIS 7.3 and 7.5 were characterized by shorter durations (~4 ka) and lower summer temperatures. The preceding cold glacial and stadial (MIS 8 and 7.4, respectively) might have led to an extensive distribution of permafrost that hindered vegetation development during the subsequent warm intervals. MIS 7.4 and 6.6 were cold and wet, probably triggered by low obliquity values and coevally low precession‐related summer insolation. As a result, these periods were marked by significantly reduced summer temperatures and an enhanced snow‐ice albedo feedback. The obtained reconstructions provide potential scenarios for future climate changes and allow a better understanding of the relationship between vegetation, climate and external/internal forcings in the high latitudes.

The Environment at Lake El’gygytgyn Area (Northeastern Russian Arctic) Prior to and After the Meteorite Impact at 3.58 Ma

“…Pollen assemblages of PZ III in section 118 (Figure 3) are dominated by Betula, Alnus and Pinus. In the El'gygytgyn pollen record (e.g., Lozhkin et al, 2007Lozhkin et al, , 2017Matrosova, 2009;Andreev et al, 2014;Zhao et al, 2018Zhao et al, , 2019, similar pollen assemblages have only been reported from the Late Pleistocene. During PZ III of section 118, larch forests with stone pines, shrub alders, dwarf birches, and ericaceous low shrubs in underbrush dominated the vegetation cover.…”

Middle to Late Pleistocene lake‐level fluctuations of Lake El'gygytgyn, far‐east Russian Arctic

“…; Zhao et al . ). The upper sandy layer (9.6–9.1 m) is probably associated with a transgression that occurred during the Allerød warming.…”

Changes in Paleovegetation and Paleoclimate in China since the Late Middle Pleistocene: A Case Study of the Dajiuhu Basin

“…The proportion of coniferous trees and warm-and-humid broadleaved trees from core DJH-2 was also compared with the trees and shrubs of the pollen record in Lake El'gygytgyn [50][51][52] (Figure 5). In Lake El'gygytgyn, the proportion of trees and shrubs also increased during MIS 7, MIS 5, and MIS 1.…”

“…During MIS 5, the vegetation was dominated by deciduous taxa, with a high percentage of Betula and Alnus pollen [50,51]. During MIS 7, the vegetation was dominated by tundra, which was mainly alder and birch [52]. [46].…”