Habitat loss of the Tsuga-dominated coniferous forest in southwestern China under global warming: Evidence from a Holocene peat record in the Wuliang Mountains

High-altitude vegetation faces severe risk of habitat loss under global warming. Long-term peat sediment records are essential to understand these dynamics. Here, we present a multi-proxy reconstruction from the Huangcaoba (HCB) peatland at the ecotone between the Tsuga dumosa forest and the mid-montane humid evergreen broad-leaved forest in the Wuliang Mountains. Together with evidence from pollen, organic carbon isotopes (δ 13 C org ), n -alkanes, and loss on ignition (LOI), we tracked the dynamics of climate and vegetation there during the Holocene. Our results show that orbital-scale cooling might have led to a downward migration of Tsuga forest by more than 300 m. Around 6 cal kyr BP, the local vegetation changed from the evergreen broad-leaved forest (dominated by Quercus (evergreen type) and Castanopsis / Lithocarpus ) to a Tsuga- dominated coniferous forest. Millennial-scale climate fluctuations triggered a shift in the species composition of montane vegetation. The results of the biomod2 model suggest that global warming may threaten the stability of the Tsuga forest in southwestern China in the future, highlighting the potential risk of habitat loss for conifer forests in low-latitude mountains.