Archaeobotanical insights on the change of subsistence from the Eastern Zhou to Han Dynasty: A case study of the Luojiaba site (Sichuan, China)

Northeastern Sichuan, located in southwestern China, was an overlooked area in Chinese history compared to the Central Plains. It was the core region of the Ba State during the Eastern Zhou Dynasty until conquered by the Qin in 316 B.C. This region went through critical transformations from the Eastern Zhou Dynasty to the Han Dynasty. Studying the subsistence strategies of northeastern Sichuan can not only shed light on the living environment, diet, economy of Ba people, but also help us understand the transformations they underwent. The Luojiaba (罗家坝) site is the best-preserved and largest Ba settlement found so far in the region and provides us an invaluable opportunity to investigate the subsistence in this region. We systematically collected flotation samples from Luojiaba site during the excavations from 2020 to 2022. Our analysis results showed that foxtail millet was the main crop, along with broomcorn millet, rice, and a small amount of wheat and pulses; however, the proportion of wheat and rice increased notably from the Warring States to the Western Han Dynasty. By integrating evidence from the fauna assemblage and production tools, we infer that Luojiaba people mainly obtained food resources through farming and fishing, foraging and animal husbandry only serve as supplements. The subsistence pattern at Luojiaba is likely shaped by both the economic traditions of the Ba people and the expanded influence of the Qin and Han central governments. The current research provided critical evidence on the cultural history of Ba people and how it gradually merged into the Han culture.