Regional Sustainability (Sep 2020)
Social development and living environment changes in the Northeast Tibetan Plateau and contiguous regions during the late prehistoric period
Abstract
The relationship between the evolution of human societies and their living environments has been discussed intensively in recent decades. It is important to understand the patterns and mechanisms of human–environment interaction and evolution in order to cope with rapidly changing environments in the modern world. We reviewed the results of dating, archaeobotanical, and zooarchaeological studies from 139 prehistoric sites in the Northeast Tibetan Plateau (NETP) and contiguous regions (NETP-CR: i.e., the Hexi Corridor and western margin of the Chinese Loess Plateau) and compared them with paleoenvironmental records to study variations in spatiotemporal patterns of social development in the area and their relationships with climate and vegetation changes. Our results show that hunter-gatherer groups occupied vast areas of the NETP at low intensities during ~15,000–5500 BP (years before present). This was directly related to forest cover and climate change. An increase in temperature and precipitation turnover of vegetation from desert steppe to alpine meadow/subalpine shrub, and recovery of animal population on the Tibetan Plateau created more food resources and space for hunter-gatherers. Millet farmers settled extensively below 2500 m a.s.l. (meters above sea level) in the NETP-CR between ~5500 and 3600 BP, and might have coexisted with hunting groups above 2500 m a.s.l. via subsistence exchange. The distribution of human settlements during that period was affected by climate change, with the relatively warm and wet climate promoting the expansion of millet agriculture to the NETP-CR during 5500–4500 BP, while climate deterioration caused humans to retreat to lower altitudes. During 3600–2200 BP, a range of livelihoods emerged in different regions of the NETP-CR. This was promoted by early trans-Eurasian exchange and the development of an agro-pastoral economy that utilized cold-tolerant crops and livestock. This eventually promoted the expansion of permanent human settlements to high-altitude areas in the NETP. This study found that human societies adopted various strategies to adapt to the changing living environment throughout late prehistoric times in the NETP-CR. The results provide a long-term perspective on the trajectory of regional socio-environmental co-evolution.
