Climate-driven reduction in biomass production of the Eurasian steppe coincides with nomadic migration during the first millennium CE
Abstract
Although it is generally accepted today that climate and other environmental factors affected past human societies at different spatiotemporal scales, direct linkages are difficult to determine, and correlation should not be confused with causation. Here, we use a tree-ring width network of multimillennial chronologies from inner Eurasia to reconstruct annual changes in Net Primary Productivity (NPP) back to 200 BCE. Our findings reveal that episodes of reduced NPP around the 70s–100s, 360s–380s, and 470s–560s CE likely contributed to the westward and southward migration of nomadic people from their homelands in northwestern China and Mongolia. Although prolonged multidecadal periods of climate-induced low NPP served as tipping points for agricultural and pastoral subsistence systems, the inherent mobility of nomadic communities not only enabled them to adapt to adverse environmental conditions but also facilitated a widespread dispersal of ethnic groups.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (19)
Feng Chen
Xiaoen Zhao
Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security/Ministry of Education Key Laboratory for Transboundary Eco-Security of Southwest China, Institute of International Rivers and Eco-Security, Yunnan University
Weipeng Yue
Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security/Ministry of Education Key Laboratory for Transboundary Eco-Security of Southwest China, Institute of International Rivers and Eco-Security, Yunnan University
Shijie Wang
Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security/Ministry of Education Key Laboratory for Transboundary Eco-Security of Southwest China, Institute of International Rivers and Eco-Security, Yunnan University
Yong Zhang
Youping Chen
State Key Laboratory of Vegetation Structure, Functions and Construction, Yunnan University
Mao Hu
Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security/Ministry of Education Key Laboratory for Transboundary Eco-Security of Southwest China, Institute of International Rivers and Eco-Security, Yunnan University
Jan Esper
Ulf Büntgen
Fredrik Charpentier Ljungqvist
Department of History, Stockholm University
Amy E. Hessl
Department of Geology and Geography, West Virginia University
Max C. A. Torbenson
Department of Geography, Johannes Gutenberg University
Yujiang Yuan
Key Laboratory of Tree-Ring, Physical and Chemical Research, Institute of Desert Meteorology, China Meteorological Administration
Martín A. Hadad
Laboratorio de Dendrocronología de Zonas Áridas-Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan, Centro de Investigaciones de la Geósfera y Biósfera, Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de San Juan
Fidel A. Roig
Laboratorio de Dendrocronología e Historia Ambiental, Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales, Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de Cuyo
Honghua Cao
Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security/Ministry of Education Key Laboratory for Transboundary Eco-Security of Southwest China, Institute of International Rivers and Eco-Security, Yunnan University
Heli Zhang
Key Laboratory of Tree-Ring, Physical and Chemical Research, Institute of Desert Meteorology, China Meteorological Administration
Yaqun Liang
School of History and Administration, Yunnan Normal University
Fahu Chen
Key Laboratory of Western China’s Environmental Systems (Ministry of Education), Lanzhou University