Dietary adaptation during the Longshan period in China: stable isotope analyses at Liangchengzhen (southeastern Shandong)

Rice and millet were staple crops at Liangchengzhen, a late Neolithic Longshan site in Shandong, China, but the degree of dietary variation is not known. This study uses stable isotope analysis of human and faunal skeletal remains to quantitatively address the importance of these crops as well as terrestrial domesticates and aquatic resources in the diet at Liangchengzhen. Although no collagen could be extracted from the poorly preserved human bones, the δ¹³C stable isotope results for 2 apatite sample and 16 tooth enamel samples averaged −9.8‰ suggesting that diet was based on foods averaging from −24‰ to −18‰, with millet and millet-fed animals comprising at most approximately 25–30% of the diet. Pig faunal δ¹³C isotope values suggested that during the earlier Longshan period pigs were fed mainly millet with more C₃ foods such as rice included by the later Longshan period. Solid ceramic residues from two guan jar sherds produced δ¹³C values averaging −18‰ and δ¹⁵N values averaging +16‰, suggesting both vessels contained fish. The results of the study indicate that by the Longshan period, people in southeastern Shandong no longer relied as heavily on millet and that the agricultural crop of rice had increased in importance at Liangchengzhen. Unfortunately, without human collagen samples to provide nitrogen isotope results, we cannot estimate the relative contribution of aquatic and terrestrial protein to the diet of people at Liangchengzhen. In general, however, the pattern of a diverse agricultural system on the basis of the macrobotanical remains from Liangchengzhen is supported by the isotopic results.