Amelioration of habitat since the early Holocene contributed to the origin of agriculture in the farming-pastoral zone of northern China

The origin of agriculture in the farming-pastoral zone of northern China remains in dispute. The central region of the Inner Mongolia Plateau is located in the core area of the farming-pastoral zone; thus, it is a critical region for exploring the origin of the dryland farming system in northern China. This study selected the Yumin Site and Banan Site, which belong to the Yumin Culture-the beginning of Neolithic culture in Inner Mongolia-as the research objects. Based on the quartz optically stimulated luminescence (OSL) dating on the sedimentary sections from the Yumin site (YM) and Banan site (BN1 and BN2), the Holocene chronology framework of each section was established. After that, by identifying carbonized grains in the Yumin site and the multi-proxy analysis of each section, we investigated the relationship between the origin of agriculture and climate change in this region. The results revealed that the timing of the origin of agriculture recorded in the Yumin site lagged behind the timing of a significant increase of precipitation during the early Holocene but coincided with the timing of a significant increase of vegetation around 8.4 ka. This phenomenon was further confirmed by the published high-resolution paleoenvironmental records from the surrounding area of the Yumin Culture. We propose that with the gradual amelioration of hydrothermal conditions since the beginning of the Holocene, the regional ecosystem had been improved, resulting in the gradual conversion of the land surface from infertile sand to organic-rich soil, providing an appropriate environmental foundation for the origin of dryland farming in northern China around 8.4 ka. This study highlighted that the "accumulative environmental effects" during the early Holocene played a vital role in the origin of agriculture in northern China and provided a reference for agricultural management in the context of future climate change.