A palaeoenvironmental study of the Shiniusi archaeological sites in the Wujiang Drainage Area, upper Yangtze River, Chongqing region, China

摘要

Environmental archaeology helps researchers understand the correlation between environmental changes and their impacts on human civilization. One such study is taking place along the Wujiang river in Chongqing, China, at and near the Shiniusi site. Moss samples were obtained under natural mountain vegetation, along with soil samples from the QST4 unit at the Shiniusi site and surface soil sites from nearby archeological sites. By combining comprehensive palynology, charcoal, and isotopic chronology analyses with cultural artifacts, and comparing the results with those from adjacent sites, historical insights were obtained. The modern pollen assemblage of the Wujiang comprises mostly monolete spores and tree pollen, with no pollen from the Brassicaceae or rice (Oryza sativa), indicating a lack of human activity. The modern pollen and spore assemblage at nearby sites contains more trilete spores than monolete spores, and increased pollen from the Brassicaceae and Poaceae, indicating increased human activity. From the Shang Dynasty to the Song Dynasty, the pollen and spore assemblage of the QST4 unit was mainly monolete spores and the pollen of trees and herbaceous vegetation, with little pollen of rice and none of the Brassicaceae. Since the Ming Dynasty (1368 to 1644 AD), the pollen and spore assemblage has approached the modern assemblage near the archeological site, with more trilete spores than monolete spores, and increased pollen from the Brassicaceae and Poaceae, indicating greater human activity correlated with cultivation of rice and brassicaceous vegetables. The dominant pollen was from the Brassicaceae, the Poaceae, and the Fabaceae in the CJ unit at the Chenjiazui archeological site from the Zhou Dynasty (1100 to 256 BC) until modern times. High contents of micro-charcoal grains <125 μm from the Shang and Zhou Dynasties to the Han Dynasty are probably correlated with natural forest fires and climate change, and show reduced human impacts. The increase in micro-charcoal grains >125 μm since the Tang Dynasty is probably correlated with local grassland burning to fertilize crops.