西辽河流域中晚全新世气候环境演变及其对农牧业演替的影响

Climate change plays a significant role in the evolution of human civilization. The West Liaohe Basin of northeast (NE) China, an area sensitive to monsoon climate change, has a prolonged history of agriculture-based civilizations, making it an ideal place to study human-landscape interactions in the Holocene. Here, analyses of multi-proxies were applied to a sediment profile (XLW) obtained near the Xinglongwa archaeological site, with a reliable chronology that covered mainly the past 5000 years. The result showed that from 5.0 to 3.7 cal. ka BP, the climate turned cooler/drier as indicated by the low magnetic susceptibility and loss on ignition (LOI), coeval with the decline of the East Asian summer monsoon (EASM). This change in climate condition coincided with the demise of agriculture-based Hongshan Culture, which was later replaced by the Xiaoheyan Culture featured by fishing and gathering livelihood. During this period, the number of Neolithic sites in NE China decreased, with a significant southward migration, possibly related to climate deterioration. After 3.7 cal. ka BP, high values of magnetic susceptibility and LOI indicated enhanced terrestrial input, which may result from the strengthening of EASM under a warming climate condition. This could have promoted the recovery of agriculture and boosted the development of the Lower Xiajiadian Culture, during which a demographic expansion was indicated by a significant increase in site numbers. After 2.8 cal. ka BP, a decreasing trend in magnetic susceptibility and LOI hinted the deterioration of EASM with a cool/dry setting, which might have caused a southward shift of settlements in the Upper Xiajiadian Culture when farming was partially replaced by pastoralism.