Pollen-based seasonal temperature reconstruction in Northeast China over the past 10,000 years, and its implications for understanding the Holocene Temperature Conundrum

• Published in: Palaeogeography, palaeoclimatology, palaeoecology Vol. 651; p. 112391
• Main Authors: Geng, Rongwei, Zhao, Yan, Herzschuh, Ulrike, Cui, Qiaoyu, Zheng, Zhuo, Xiao, Xiayun, Ma, Chunmei, Liang, Chen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024
• Subjects: Holocene; Northeast China; Paleoclimatology; Pollen; Quantitative reconstruction; Paleoclimatology; Pollen; Northeast China; Holocene; Quantitative reconstruction
• ISSN: 0031-0182
• DOI: 10.1016/j.palaeo.2024.112391

The Holocene Temperature Conundrum refers to the mismatch between proxy-based temperature records and those based on climate model simulations. A possible reason for this mismatch is a putative proxy-based bias in reconstructed summer temperatures, and therefore, regional reconstructions of seasonal temperature are crucial for resolving the conundrum. In this paper, we reconstruct vegetation and climate changes over the last ∼10,000 years BP based on a high-resolution pollen record from Gushantun peatland, Changbai Mountains, Northeast China. Multiple quantitative reconstruction approaches were used and weighted averaging partial least squares regression (WAPLS) was found to be the most appropriate method for reconstructing Holocene temperature and precipitation. The reconstructed climate record shows that the Holocene Climate Optimum occurred between 8 ka and 6 ka and exhibited a cold month mean temperature that was 3 °C warmer than modern temperatures. Climate gradually cooled during late Holocene with a minimum cold month temperature of −19.6 °C. Four prominent cold events occurred around 8.7 ka BP, 7.8 ka BP, 5.7 ka BP, and 2.5 ka BP with an amplitude variation up to 3 °C. The synthesized seasonal temperature time series and a comparison with other proxies show that the decreasing trend in mean annual temperature is not a seasonal bias caused by summer temperature change. This study provides evidence of a Holocene seasonal temperature change at a regional scale and insights for further understanding of the Holocene Temperature Conundrum. •Reconstructed seasonal temperature changes based on a new high-resolution fossil pollen record in the Changbai Mountains•Synthesized climatic series in Northeast China to investigate the characteristics of regional temperature changes and their driving factors•Reconstructed winter temperature as evidence to address the alleged seasonal bias for the Holocene temperature conundrum