Contextualizing human migration in different agro-ecological zones in ancient China

Unique agricultural practices engender regional variations in cultural customs, which pave the way for diverse regional migration patterns at discrete geographic levels. In this regard, the long-term fluctuation of land carrying capacity and its association with the frequency and pattern of migration in China at the sub-national level has not been scientifically investigated. In the present study, we base on fine-grained historic migration records, together with statistical analysis (correlation analysis, Granger Causality Analysis, and multi-variate linear and Poisson regression analyses), to explore the relationship between land carrying capacity and migration in China at the sub-national level over the past two millennia. Our results quantitatively demonstrate that in the pastoral region, climate change, which is one of the major determinants of land carrying capacity, has a major role in triggering migration. In the rice region, migration is more influenced by population pressure, another major determinant of land carrying capacity. The wheat region, located between the pastoral and the rice regions, displays the combined patterns of the two regions. Our findings also reveal the importance of regional cultural and geographic context in shaping migration patterns in various agro-ecological zones in ancient China. Based on our results, the application of a "PushePull Model" in interpreting historic Chinese migration is revisited with quantitative evidence. This study provides timely empirical proof of a "nature-human" interaction founded on diverse cultural traditions over an extended period which other scientists and policymakers can use as reference in initiating actions that can prevent agriculturalist-pastoralist conflicts. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.