High resolution record of vegetation and climate change in Western Beringia (Yana–Indighirka Lowland) at the end of the Late Pleistocene

The discovery of the Yana site complex (~32,000 BP) has intensified inquiry into the Late Pleistocene environments of Western Beringia, a critical factor shaping transcontinental species distributions and the initial human settlement of the Arctic. This study presents a high-resolution environmental and climatic record for the period 37,000 to 10,000 14C years ago (ca. 41,800–11,500 calBP), organized into 500- to 1,000-year time slices. We trace the transformation of vegetation from hemi-cryophytosteppe and tundra–steppe communities during marine isotope stage (MIS) 3 to tundra and shrub tundra in the early Holocene, culminating in a profound landscape restructuring during Holocene warming (~11,500 years ago). Quantitative paleoclimatic reconstructions are based on minimum and maximum deviations from modern values for the temperature of the warmest month (Twm), average annual temperature (Tann), and average annual precipitation (Pann). Our results reconstruct the main climatic trends in western Western Beringia and detail the sequence of fluctuations during MIS 3 and MIS 2. We precisely define the transition to MIS 2, quantify the duration of the Last Glacial Maximum, identify Late Glacial climatic events corresponding to the European Blytt–Sernander scheme, and reveal early Holocene changes that drove radical landscape transformation. This constitutes the first such detailed reconstruction for Western Beringia. The identified climate fluctuations show strong agreement with the North Greenland Ice Core Project Greenland ice core record. We conclude that natural conditions during the studied interval, encompassing the second half of MIS 3 and all of MIS 2, were suitable for human occupation in the western Arctic part of Beringia.