Fuel use pattern of pottery kilns in Longhucun site (3200–2600 cal BP), the Chengdu Plain, southwest China

Developed pottery manufacture was one of the key subsistence patterns of Shierqiao culture (3200–2600 cal BP) in the Chengdu Plain, southwest China. Current researches mainly focus on the structure of pottery kilns, ingredients, and production techniques of potteries. However, botanical constituents of fuels used in pottery kilns were lack of research. In Longhucun site, as a representative site of Shierqiao culture, one group of pottery kilns consisting of 19 kilns was concentratedly discovered, providing crucial materials for investigating fuel utilization in ancient pottery production. In present study, samples of soil sediments from these kilns were systematically collected for identifying the composition of fuels by using the methods of phytolith analysis and wood charcoal anatomy. Results demonstrate that origin of fuels exhibits significant diversity. Phytolith analysis revealed that herbal fuel was dominated by Poaceae plants. By-products of crop processing, like leaves might also be used as fuels, although in smaller proportions. In addition, results of charcoal anatomy suggested that primary wooden fuel was composed of bamboo (Bambusoideae) plants, with additional presence of other taxa, such as Ehretia sp., Prunus sp., Ligustrum sp., Pteroceltis sp., Ilex sp., and Rhododendron sp. Depending on different influencing factors, such as availability of local vegetation and combustion properties of plant materials, strategies of purposeful fuel collection were employed by Longhucun inhabitants. This study provides brand novel insights for exploring the composition of fuels used in pottery firing during Shierqiao culture, which have been previously overlooked, and also offers important methodological references on fuel research.