Evolution of prehistoric adaptation strategies to environmental change in the Lake Qinghai Basin since 15ka BP

The Lake Qinghai Basin is a typical area for studying the relationship between climate change and human activities. However, there are few studies on the coupling of human activities and climate and environmental changes over 10000 years. This study, combining climate reconstruction sequences and prehistoric archaeological remains, reveals the evolution of prehistoric adaptation strategies in the Lake Qinghai Basin since 15ka BP. The results revealed that: (1) In 15-10ka BP, the hunters using microlith first entered the east coast of the lake, mainly hunting large mammals, which was adapted to the warm-dry climate and grassland environment; in 10-6ka BP, the use of silicic stone to make microlith, and new tools such as bone grinding and edge scraping began to appear, the hunting efficiency and intensity were improved, and the broad spectrum of food was further strengthened in warm-wet climates, mainly large and medium sized mammals; in 6-2.6ka BP, the hunter-gatherer stage changed to the animal husbandry stage, and prehistoric humans adapted to the steppe environment in cold-dry climate, and their range expanded to the entire lake region. (2) In the warm-wet stage, the range of prehistoric human activities decreased slightly, but the intensity increased, showing the characteristics of aggregation, the subsequent cold-dry stage showed an active trend, which provided important information for further study. (3) At early stage, prehistoric humans adopted the strategy of small-scale short-term hunting and gathering and high-mobility migration; at middle stage, larger long-term or seasonal hunter-gatherer strategies were adopted; at later stage, the cultural exchanges between the East and the West gradually became significant, and diversified survival strategies with animal husbandry as the main, fishing and hunting and agriculture as the auxiliary gradually formed.