The nature of an Anthropocene has been increasingly discussed and debated in the last two decades, with a focus on the arguments for or against the “Anthropocene” as a geological epoch. Some argue for an onset of Anthropocene between 1945‒1964 AD, when intensive atmospheric nuclear testing resulted in peak values of 14C that is widely recorded in tree rings and sediments, while other scholars argued its beginning may be traced back to the early Holocene. This latter argument is related to the beginnings of significant landscape modification through the development and spread of agricultural practices in old world since 10000 a BP. The Yellow River valley of northern China is the center for the domestication of millet crops (broomcorn millet and foxtail millet), however, the intensification and expansion of millet-based agriculture during the Neolithic period and its impact on the environment has not been well understood. Recent development of archaeometry methods and their application to archaeological research, such as archaeobotanical studies, and carbon and nitrogen isotope analysis of human and animal bones unearthed from Neolithic and Bronze sites in north China, has greatly deepened our understanding of the timing of millet-based agriculture and its development. In parallel, the analysis of paleoenvironment proxies including black carbon and pollen assemblages from natural sediments, has shed light on the impact of human slash-and-burn cultivation on their surrounding environments during both prehistoric and historical times. This paper reviews carbon isotope analysis of human, pig and dog bones, and radiocarbon dates from Neolithic sites, and compares them with black carbon content from palaeoenvironment records in northern China, in order to explore the temporal-spatial intensification and expansion of millet-based agriculture in the area and its possible impact on environment. It can be concluded that millet cultivation was an auxiliary subsistence strategy in northern China from 10000 to 7000 a BP with hunting-gathering the primary subsistence strategy, the earliest millet-cultivation might have emerged in eastern Inner Mongolia post 7700 a BP. Millet cultivation transited from a secondary strategy to become dominant in the Guanzhong area of north-central China during 7000‒6000 a BP, and probably facilitated the development of early Yangshao culture in the middle reaches of the Yellow River valley. Intensive millet-based agriculture emerged and widely expanded across the Yellow River valley in northern China during 6000‒4000 a BP. This promoted rapid population growth and cultural evolution in the late Neolithic period, and was key in the subsequent emergence of the ancient Chinese civilization. The temporal-spatial variation of black carbon (EC-soot) corresponds well with the intensification and expansion of millet-based agriculture during Neolithic period. The content of EC-soot increased in sediments of Daihai lake and the Horqin sandy lands in Inner Mongolia from about 7500 a BP soon after farming of millet appeared in Xinglongwa and Xinglonggou sites nearby, which evidently increased in Shaanxi Province of north central China post 6000 a BP, when intensive millet-based agriculture firstly emerged in the area. This suggests millet agriculture production activities exerted significant impact on fire frequency in northern China during the Neolithic, and thus the scale and intensity of the impact of farming increased from that period. This work provides a valuable case study for understanding the temporal and spatial development of millet agriculture, and human-environment interactions in northern China during Neolithic period from an Anthropocene perspective.
The Hexi Corridor of northwestern China was a principal axis of cultural interchange between eastern and western Eurasia during the prehistoric and historic epochs. Neolithic groups began dense settlements in Hexi Corridor after 4300 BP with millet crops and polychrome pottery from north China and bronze from Central Asia around 4000 BP accompanied by wheat, barley, and sheep. The impact of these activities on the environment during the late Neolithic and Bronze Age is not clearly understood. Therefore, we analyzed the Cu concentrations of samples collected within cultural layers of anthropogenic sediments from 17 Late Neolithic and Bronze Age sites located within the Hexi Corridor. The Cu content is reported in view of the archaeological and paleoclimatic research undertaken in the area. Our results enabled us to explore the variety of human impact on the environment before and after the introduction of bronze technology into Hexi Corridor. During 4300–4000 BP, Cu concentrations of the anthropogenic sediments were constrained within natural background values. However, from 4000 to 3400 BP, they increased substantially and far exceeded the natural background. The Cu concentrations then declined and remained above the natural background from 3000 to 2400 BP. Our work suggests that the introduction of copper melting technology led to human alteration of sediments’ chemical properties in their surrounding environments in Hexi Corridor since 4000 BP; its intensity was closely related to human settlement density, which was further affected by climate change and livelihood transition in the area during Bronze period.
The Proto-Shang, the Shang and the Zhou dynasties (∼2000–221 BCE: Before Common Era) are key periods in the origin and evolution of ancient civilizations in China since the periods include the processes and mechanisms of social development in the Central Plains of China during the Bronze Age. However, human-environment interactions in the context of trans-Eurasia cultural exchange during that time are not well-understood. In this study, isotopic analysis and radiocarbon dating of human and animal bones from Xinancheng cemetery in southeast Shanxi Province are reported. It was deduced that, for the period ∼1000–800 BCE, humans buried in Xinancheng cemetery relied primarily on C4-based foods and upper-status individuals consumed more animal protein and probably C3 crops. Also, considering the paleoclimate and other archaeological data of the Central Plains, the human diet and subsistence strategies changed significantly with more C3 staples such as wheat being consumed during the Eastern Zhou (770–221 BCE), as evidenced by an increased intake of wheat by lower-status individuals and the development of a mixed wheat and millet agricultural system. It is argued that the socio-economic change around the late western Zhou-early eastern Zhou Dynasty occurred as a result of the necessity to adapt to the aggravation caused by climate deterioration and population pressures, factors which profoundly influenced the economic and lifestyle patterns in ancient China. The socio-economic system of the Eastern Zhou Dynasty displayed more resilience to climate change than that of earlier periods.
The Gansu–Qinghai region lies in the key position for trans-Eurasian cultural exchange, and hence investigations of the history of agricultural development in this region are significant for understanding the spatiotemporal evolution of prehistoric crop dispersal in Eurasia. However, systematic archaeobotanical studies concerning the history of the development of prehistoric agriculture in this area are scarce. Here, based on archaeobotanical analysis and radiocarbon dating at the Jinchankou site, we investigated the history of agricultural development in the Datong River valley during the Qijia culture. Combined with previous archaeobotanical studies of the Gansu–Qinghai region, we explored the diachronic changes in the cropping patterns from the Late Neolithic to the Early Iron Age. The results suggest that millet remained the most important subsistence plant during 4100–3700 BP, while barley and wheat were first cultivated around 3900 BP at the Jinchankou site. Humans only cultivated foxtail and broomcorn millet in the Gansu–Qinghai region with a high level of agricultural management during 5900–4000 BP. Barley and wheat were added to the agricultural system in the area during 4000–3600 BP, although they played a subsidiary role compared with millet. During 3600–2100 BP, barley played an increasingly important role in the Gansu–Qinghai region but with evident differences among geomorphic units, and there was an obvious decrease in agricultural management level. It is likely that the transformation of cropping patterns and agricultural management levels in the Gansu–Qinghai region from 5900 to 2100 BP was primarily promoted by prehistoric trans-continental cultural exchange and secondly by climate change in the area.