Wood use and forest management by Neolithic millet farmers at the Xinglong site, northern China

The origin and development of agriculture and its relationship with climate change are hotly debated topics among environmental archaeologists. In this study, we analyzed wood charcoal materials from the Neolithic Xinglong site in northern China in order to understand the woody vegetation around the site and how early millet farmers shaped local woodlands. Our results suggest that the area around the Xinglong sites during 8700–7000 yr BP was primarily woodlands, including Prunus sibirica shrubs, Ulmus and Acer forests, and Populus stands near waterways. From 8000 to 7000 yr BP, the warm and humid climate probably contributed to the expansion of Acer, Rhamnus, and Juniperus, and may have facilitated the development of early millet agriculture. Among these ancient wood fragments that we studied, the high percent of Prunus charcoal appears to indicate an abundance of fruit trees, which might have constituted the main component of local vegetation. Meanwhile, the wood taxa illustrate the existence of a variety of ecological habitats, and it is logical to assume that people made full use of the locally available wood resources. Notably, Populus and Ulmus were the dominant sources of fuel. The results of tree-ring curvature analyses indicate that people mainly collected trunks or large branches of Ulmus, Populus, Acer, and Juniperus timbers. We interpret the increasing use of Prunus twigs and the declining percentage of Prunus charcoal in the period between 8000–7000 yr BP as indicating that people started to protect and manage wild fruit trees. They may have started pruning to acquire more food resources as part of the cultural responses and adaptation strategies employed by these early millet cultivators.