Vegetation, agriculture and social change in late NeolithicChina: a phytolith study

Late Neolithic and Early Bronze Age Central China was the scene of important cultural developments, which impacted on agricultural practices and local vegetation. Using phytolith data from 4 archaeological -sites and a survey of a further 11 sites in Henan this project investigates changing crop choices, developments in crop processing and, to a lesser extent, differing local environments both temporally and spatially. Comparisons of relative levels of phytoliths from crop husks, Panicum, Setaria and Oryza, from each site and period were compared to provide evidence of changes in crop repertoire. Results from these investigations show crop variation both over time and in different parts of the region. Millet farming predominated in the more Northern sites in the Yellow River Valley, while rice was clearly the main crop at Baligang, the southernmost site within the Yangtze catchment. However, rice became more important in the Yellow River valley during the late Neolithic and interestingly despite a changing climate making rice farming more challenging in the Early Bronze Age farmers continued rice cultivation. Crop processing stages were interpreted by examination of differing proportions of phytoliths from crop husks, weed husks and crop and weed leaves which can illustrate differing cultivation systems, harvesting and processing practices. These can be seen especially clearly in the rice data from Baligang suggesting more successful agricultural practices and possible change in social organisation in the Late Neolithic. Evidence of local environmental variation was more challenging to unpick as all the phytolith samples available were from cultural contexts. However, the results of the investigation into the changing local environment reflect other proxy data. Differences in occurrence of specific key phytolith short cell morphotypes and changes in the levels of bulliforms, and cone shaped phytolith morphotypes from Cyperaceae indicating wetland were used to interpret local vegetational change, again both spatially and temporally. Rondel and bilobe shaped short cells represent Pooid and Panicoid grasses respectively and short cell morphotypes, such as rondels, bilobes, saddles, can also be used to track variation in levels of C3 and C4 grasses, so changes in proportions of these morphotypes can indicate larger vegetational change. A comparison between the dataset from Neolithic Central China and one from Neolithic India highlighted possible variations in arable systems with millet and wet rice farming in China contrasting with dry rice in India.