Abundance of Liquidambar during MIS 5 indicates a significantly warmer climate than MIS 1 along the South Yellow Sea coast

Abstract

The relative warmth of different interglacial periods provides crucial insights into climate system sensitivity under varying boundary conditions. While global proxy records indicate that the Last Interglacial (MIS 5, specifically MIS 5e) was warmer than the present Holocene (MIS 1), quantitative terrestrial evidence from temperature-sensitive proxies in East Asia remains scarce. In this study we present a new high-resolution palynological record from core LYK-1 in the western South Yellow Sea (SYS), spanning from MIS 5 to the present, to quantitatively assess the relative warmth of these two interglacials. We utilize the pollen of Liquidambar, a thermophilous genus with stringent climatic requirements, as a key temperature proxy. By integrating pollen data with robust lithological, foraminiferal, and chronological controls, we first disentangle the influences of sea-level change and depositional environment on the pollen assemblages to isolate the climatic signal. By further comparison with the surrounding records, the results reveal a striking contrast: Liquidambar pollen is significantly more abundant during MIS 5 than MIS 1. This indicates that the MIS 5e climate along the SYS coast was substantially warmer and more humid than the Holocene, allowing for a notable northward expansion of subtropical flora. The herbaceous pollen dominance throughout the core is interpreted as a signature of fluvial transport dynamics in this inner-shelf setting rather than a purely open landscape. This well-dated record provides robust terrestrial evidence for a significantly warmer MIS 5 in East Asia, underscoring the region's sensitivity to interglacial intensity and offering a valuable paleo-analogue for understanding future warming scenarios.