What caused the mid-Holocene cultural discontinuity on the Yunnan-Guizhou Plateau?

During the mid-Holocene, a period marked by the rapid development of Chinese civilization, the Yunnan-Guizhou Plateau experienced a distinct but poorly understood cultural discontinuity, primarily between 7 and 5 ka BP, characterized by sparse archaeological sites and interrupted cultural succession. By examining the heterogeneous hydroclimatic characteristics, differential ecological responses, and ages and quantities of archaeological sites on the Yunnan-Guizhou Plateau, we suggest that the adaptive behaviors of early communities in response to heterogeneous hydroclimatic changes likely served as the primary driver of the mid-Holocene cultural discontinuity in this region. Further excavating archaeological evidence and developing proxies for human activities, reconstructing prehistoric early human activities, and exploring the adaptation of ancient humans to climatic and ecological changes, as well as the intrinsic driving mechanisms, constitute the foundation for policy-making from a surface Earth system perspective to maintain the sustainability of regional coupled human-nature systems.

The Yunnan-Guizhou Plateau is located at the crossroads of East Asia, Southeast Asia, and South Asia. Numerous archaeological sites dating to the Paleolithic, Neolithic, Bronze Age, and historical periods have been unearthed in this region, providing valuable clues for understanding the origin of modern humans in East Asia, material and cultural exchanges, and the formation and evolution of the integrated pluralism of Chinese civilization. The mid-Holocene, especially the period 7–5 ka BP (i.e., 5,000–3,000 BC), was a critical stage for the rapid development of Neolithic cultures in China. However, compared with the Yellow River reach and the middle and lower Yangtze River reaches, the Yunnan-Guizhou Plateau exhibited an obvious cultural discontinuity during this interval, characterized by the absence of archaeological remains or discontinuous cultural development (often referred to as the “cultural gap of the Yunnan-Guizhou Plateau”). For example, the probability density of radiocarbon ages from archaeological sites indicates that sites are rare on the Yunnan-Guizhou Plateau during 7–5 ka BP, and the number of sites increased rapidly after 4,000 ka BP,1,7,8 which is similar in trend to the lake-level trend in Lake Chenghai in Yunnan Province and the precipitation trend inferred from sedimentary Fe/Mn ratios in Lake Caohai in Guizhou Province. In contrast, this pattern is out of phase with the probability density of 14C ages in the northeastern Qinghai-Tibet Plateau: numerous archaeological sites occurred during 8.5–7.5 ka BP, fewer existed during 7.5–5.5 ka BP, sites increased rapidly during 5.5–4 ka BP, and then decreased after 4 ka BP. At present, there is no consensus regarding the cause of the mid-Holocene cultural gap on the Yunnan-Guizhou Plateau, whether it is driven by heterogeneous hydroclimatic patterns or related to the adaptation strategies and migrations of prehistoric humans, and whether early ancestors had not yet arrived in this region during this period remains unclear.