Abstract ID: 3.9951 | Accepted as Talk | Talk/Oral | TBA | TBA

Climate variability exerts a fundamental influence on vegetation dynamics and human social development. Recent studies have identified a stable ~500-year climate-vegetation cycle in the East Asian Monsoon (EAM) region over the past 20,000 years. This cyclic variation not only shaped vegetation patterns during the Last Deglaciation, but also profoundly influenced prehistoric human activities and cultural evolution throughout the Holocene. During the Last Deglaciation, high-resolution palynological records and time-series analyses from Xiaolongwan Maar Lake, Jilin Province, reveal a seesaw-like alternation between temperate deciduous forests and boreal coniferous forests with steppe, corresponding to shifts between warm-wet and cold-dry phases of the EAM. This 500-year periodicity is closely linked to the frequency of El Niño-Southern Oscillation (ENSO) events, highlighting the role of low-latitude ocean-atmosphere processes in modulating high-latitude monsoon dynamics. During the Holocene, this 500-year cyclicity continued to dominate EAM intensity and had a significant impact on prehistoric human activities in northeastern China. High-resolution pollen records and radiocarbon probability density analysis of archaeological sites indicate a strong correlation between warm-humid climatic phases and periods of cultural prosperity. For example, the emergence of the Xinglongwa culture (~7570 cal yr BP) and the Zhaobaogou culture (~6770 cal yr BP) coincided with periods of increased monsoonal precipitation, suggesting that warm and humid conditions facilitated the development of prehistoric societies. This periodicity is likely to be driven by ENSO variability induced by solar activity. Overall, the 500-year climate cycle, superimposed on orbital-scale climatic background changes, played a critical role in shaping prehistoric cultural evolution in Northeast Asia. Favourable warm and humid conditions enhanced plant and animal productivity, thereby fostering the development and prosperity of early human societies and civilisations in the region. This study systematically reveals for the first time a stable 500-year climate-vegetation-human activity cycle since the last deglaciation, providing crucial insights into centennial to millennial-scale climate variability and its impacts on ecosystems and human societies.