TY - JOUR A1 - Courtin, Jérémy A1 - Andreev, Andrei A1 - Raschke, Elena A1 - Bala, Sarah A1 - Biskaborn, Boris A1 - Liu, Sisi A1 - Zimmermann, Heike A1 - Diekmann, Bernhard A1 - Stoof-Leichsenring, Kathleen R. A1 - Pestryakova, Luidmila Agafyevna A1 - Herzschuh, Ulrike T1 - Vegetation changes in Southeastern Siberia during the late pleistocene and the holocene JF - Frontiers in Ecology and Evolution N2 - Relationships between climate, species composition, and species richness are of particular importance for understanding how boreal ecosystems will respond to ongoing climate change. This study aims to reconstruct changes in terrestrial vegetation composition and taxa richness during the glacial Late Pleistocene and the interglacial Holocene in the sparsely studied southeastern Yakutia (Siberia) by using pollen and sedimentary ancient DNA (sedaDNA) records. Pollen and sedaDNA metabarcoding data using the trnL g and h markers were obtained from a sediment core from Lake Bolshoe Toko. Both proxies were used to reconstruct the vegetation composition, while metabarcoding data were also used to investigate changes in plant taxa richness. The combination of pollen and sedaDNA approaches allows a robust estimation of regional and local past terrestrial vegetation composition around Bolshoe Toko during the last similar to 35,000 years. Both proxies suggest that during the Late Pleistocene, southeastern Siberia was covered by open steppe-tundra dominated by graminoids and forbs with patches of shrubs, confirming that steppe-tundra extended far south in Siberia. Both proxies show disturbance at the transition between the Late Pleistocene and the Holocene suggesting a period with scarce vegetation, changes in the hydrochemical conditions in the lake, and in sedimentation rates. Both proxies document drastic changes in vegetation composition in the early Holocene with an increased number of trees and shrubs and the appearance of new tree taxa in the lake's vicinity. The sedaDNA method suggests that the Late Pleistocene steppe-tundra vegetation supported a higher number of terrestrial plant taxa than the forested Holocene. This could be explained, for example, by the "keystone herbivore" hypothesis, which suggests that Late Pleistocene megaherbivores were able to maintain a high plant diversity. This is discussed in the light of the data with the broadly accepted species-area hypothesis as steppe-tundra covered such an extensive area during the Late Pleistocene. KW - last glacial KW - Holocene KW - Lake Bolshoe Toko KW - paleoenvironments KW - sedimentary ancient DNA KW - metabarcoding KW - trnL KW - pollen Y1 - 2021 U6 - https://doi.org/10.3389/fevo.2021.625096 SN - 2296-701X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Palagushkina, Olga V. A1 - Wetterich, Sebastian A1 - Schirrmeister, Lutz A1 - Nazarova, Larisa B. T1 - Modern and fossil diatom assemblages from Bol’shoy Lyakhovsky Island (New Siberian Archipelago, Arctic Siberia) JF - Contemporary Problems of Ecology N2 - This article discusses the results of a taxonomic and ecological investigation of diatoms from polygonal ponds and Quaternary permafrost deposits of Bol’shoy Lyakhovsky Island (New Siberian Archipelago) and the reconstruction of climatic changes on the Island during late Pleistocene/Holocene transition using fossil diatom assemblages from the permafrost deposits. The taxonomic list of diatoms includes 159 diatom species. The main ecological factors that determine the distribution of diatoms in the investigated data set are mean July air temperature, рН, electrical conductivity, water depth, and concentrations of Si4+ and Al3+. An increase in water depth and stable lacustrine conditions in the Lateglacial–Holocene in the ancient thermokarst lake relate to Lateglacial warming before 11860 ± 160 years BP and during the early Holocene between 11210 ± 160 and 7095 ± 60 years BP. KW - Pleistocene KW - Holocene Y1 - 2017 U6 - https://doi.org/10.1134/S1995425517040060 SN - 1995-4255 SN - 1995-4263 VL - 10 SP - 380 EP - 394 PB - Pleiades Publ. CY - New York ER -