The Late Weichselian/Holocene transition on the East European Plain: New multi-proxy data for palaeoenvironmental reconstructions from a postglacial kettle hole (Serteya Mire, Western Russia)

Few sites in the East European Plain have yielded detailed multi-proxy data for the late Weichselian to Holocene transition. This paper provides a comprehensive palaeobotanical analysis of the lower part of a core of biogenic deposits from the Serteya Mire in the western part of the East European Plain (Western Russia). The studied reservoir, is located in a kettle hole and is dated to the Allerød, as confirmed by radiocarbon dating of the basal peat layer. It offers a unique bioarchive of 13.5 m of organic deposits. Detailed palaeobotanical studies were carried out, including analyses of pollen, plant macrofossils, microcharcoal, diatoms, microbiomorphic, as well as geochemical and sedimentological analyses. The palaeoecological reconstructions are based on reliable depth-age model elaborated on a large 14 C dataset. This multi-proxy approach highlights the complex interactions between climate, vegetation and hydrological conditions in the period from ca. 13,050 to ca. 8200 cal. BP – that is, the Late Allerød, the Younger Dryas and Greenlandian stage of the Holocene (Early Holocene). In the Late Allerød, a wetland developed which evolved into a lake. The results of pollen analysis show a clear transition from the Weichselian to the Holocene and reveal significant floristic changes characterised by a dominance of pine in the Late Weichselian, followed by spruce and birch, and later by broadleaf trees in the Early Holocene. The presence of wild herbivores is documented by no-pollen palynomorphs (NPPs) except between 10,000 and 8800 cal. BP. The fluctuations of the palaeolake water level, trophic state and pH were recorded in the diatom analysis results, which shows that periphyton and benthic diatoms are the dominant species. The lake ecosystem was regularly affected by fires, especially around 13,000–12,700 BP and from 8700 BP. Finally, this record contributes to broader reconstructions of postglacial ecosystem dynamics in lowland periglacial landscape.