High-resolution analyses of annually laminated sediments of Lake Shira to reconstruct Holocene environmental variability and its relation to natural climate drivers and human occupation in northern Inner Asia

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For 45,000 years, northern Inner Asia has been an important crossroads region that witnessed waves of human migrations and facilitated cultural and technological exchange. Beginning 5,000 years ago, it saw the spread of early agropastoral societies from East and West Eurasia, their mingling and transformation, and the gradual and selective adoption of domesticated animals and plants by indigenous peoples. In the Bronze Age, the region became a cradle of major technological innovations and powerful nomadic empires that strongly shaped cultural and political developments throughout Eurasia. However, little is known about the impact of early agropastoral economies on natural environments and the effect of climate change on cultural developments. Due to anthropogenic global warming, the region is considered to be highly vulnerable, as rising temperature and evaporation, for example, could affect vegetation composition and increase the likelihood of wildfires and sandstorms. However, there is still a lack of high-quality proxy records from northern Inner Asia that could provide a better understanding of climatic impacts on the regional environment as well as new insights into human-environment interactions. The varved sediments of Lake Shira in the Altai-Sayan region have been recognised as a valuable archive of climatic and environmental variability over the last 8,000 years. The proposed project aims to analyse a new set of sediment cores recovered from the lake in March 2021 to (1) establish a robust chronology for the sedimentary sequence through microscopic varve counting and radiocarbon dating, (2) obtain a detailed reconstruction of the regional vegetation, fire and climate histories through high-resolution pollen and microcharcoal analyses, and (3) reconstruct hydroclimatic and limnological changes through analyses of aquatic non-pollen palynomorphs and sediment properties. A fourth goal is the synthesis of archaeological site and radiocarbon data from northern Inner Asia to reconstruct spatial and temporal patterns of population dynamics and subsistence changes during the Middle and Late Holocene. The results of the proposed project will fill gaps in our knowledge of climate and environmental changes, human settlement dynamics, colonization, and adaptations in the study region during the last 8,000 years, and are therefore essential for understanding transcontinental processes.