Tracking Holocene climate, fire, and human activities in southern Korea using pollen and charcoal records.

The Holocene in the Korean Peninsula offers an ideal natural laboratory for evaluating long-term interactions among climate, vegetation, fire, and human activity. We present high-resolution pollen and sedimentary charcoal records from paleo-lake Gaho in southern Korea covering the last ~7,000 years, and derive quantitative reconstructions of mean annual temperature and annual precipitation using the modern analogue technique and an extensive modern pollen dataset. The temperature estimates (approximately 9–12°C) capture millennial-scale variability linked to changes in the East Asian winter monsoon and Bond-scale events, whereas reconstructed precipitation (around 1,250–1,540 mm) follows shifts in the Intertropical Convergence Zone and the strength of the East Asian summer monsoon. Hydroclimate signals inferred from pollen are consistent with lake-level changes, geochemical indicators, and multivariate statistical analyses. Charcoal influx records indicate persistent fire occurrence throughout the Holocene, with a marked rise in large-scale burning around 5.0–4.0 ka BP, likely associated with progressive drying and increased fuel availability. After ~3.0 ka BP, the appearance of abundant large Poaceae pollen (>40 μm) suggests expansion of agriculture, and pronounced fluctuations in Pinus and Quercus after ~2.0 ka BP indicate intensifying human disturbance. We infer that late Holocene fires were increasingly anthropogenic, associated with land clearance, warfare, and metallurgical activities rather than purely climatic forcing. Overall, our results demonstrate the coupled evolution of climate, ecosystem dynamics, and human impact in southern Korea during the Holocene, providing important context for anticipating ecosystem responses under ongoing climate change.