Settlement distribution and its relationship with environmental changes from the Paleolithic to Shang–Zhou period in Liyang Plain, China

Abstract

With increasing collaboration between archeology and natural sciences, research on past human–environment interactions has received more attention in recent years. This paper uses nineteen radiocarbon and OSL dates from three profiles to explore environmental evolution of the Liyang Plain, investigate the spatial and temporal distributions of archaeological sites from the Paleolithic Age to the Shang–Zhou period and discuss relationships between human cultures and environmental changes. The results show that Paleolithic sites are mainly distributed in surrounding mountainous and hilly areas, changing to the plain in the late Paleolithic Age. Climatic cooling during the Last Glacial Maximum did not cause severe damage to the regional vegetation and ecosystem, which allowed the continuous development of the late Paleolithic culture in the Liyang Plain. Suitable environmental conditions and progression of human activities facilitated rice cultivation in the early Holocene, and rice agriculture as an important food resource provided a solid material foundation for social development. The number of archaeological sites increased continuously and their distribution expanded considerably into eastern low-lying plain areas during the Neolithic Age. These trends reversed in the late Shijiahe culture, and social development did not recover until the Shang–Zhou period. Variation of site distribution in the Liyang Plain was primarily influenced by hydrological and geomorphological changes as well as climate change. However, it might also have been affected by broader regional political situations, especially during the Shang–Zhou period.

Introduction

With the increase in amount of collaborative research on environmental change and archaeology, researchers have realized that paleoenvironmental changes and paleocultures may be closely related. Past human–environment interactions have been increasingly studied in recent years (Mo et al., 1996, Gupta, 2004, Kuper and Kropelin, 2006). Changes of environmental factors, such as climate, landscape, and hydrology may affect human activities to some extent and even determine the rise and decline of cultures (Hodell et al., 1995, Dodonov et al., 2007, Turney and Brown, 2007). However, to adequately define the relationship between past human and their surrounding environment is still challenging, because of the lack of high-resolution environmental archives or archaeological materials.

The Liyang Plain which lies in the northwest of Hunan province, in the middle reaches of the Yangtze River, is an important area for the development of prehistoric cultures. It has a long habitation history that can be traced to the Paleolithic Age. During the Neolithic Age, ancient people intensively occupied the Liyang Plain, practicing rice cultivation and creating splendid cultures. During the last few decades, the quantity of archaeological field surveys and excavations has increased greatly, which has facilitated the establishment of an intact and successive Neolithic cultural sequence and accumulation of archeological materials. Several stalagmites collected from caves in southern China were fully studied, which provided precisely dated, high-resolution environmental records (Dykoski et al., 2005, Shao et al., 2006, Cosford et al., 2008, Hu et al., 2008). These reconstructed data laid the material foundation for environmental archaeology in this region. Yasuda et al. (2004) conducted environmental archaeological study at the Chengtoushan site and suggested that small-amplitude climate changes triggered technical innovation. A significant climatic cooling at 4200–4000 cal. BP brought about the collapse of the rice cultivating society in the Yangtze River basin (Yasuda, 2008). However, these studies were mostly concentrated in one single site or one special period, and comprehensive studies on the relationship between environmental changes and human activities were rare. During the last few years, the authors have made preliminary studies on depositional environments and paleoenvironmental evolution in the Liyang Plain, based on fieldwork and laboratory analysis (Mao et al., 2009, Mao et al., 2010, Guo et al., 2013). In this study, we investigated the spatial and temporal patterns of the distribution of archaeological sites from the Paleolithic Age to Shang–Zhou period. Combined with reconstructed environmental records, past human–environment interactions were the focus.