The Demographic Changes and Their Driving Forces on the Loess Plateau since 4000 Years BP

Abstract

The intensity of human activities on the Loess Plateau (LP) could affect the ecological health and socioeconomic development of the area and the lower reaches of the Yellow River (YR). Population size/density is used as an important indicator to evaluate the intensity of human activities, but there has been little research on its variation in history. Therefore, this study provided a comprehensive analysis of the change characteristics, drivers and development stages of the population on the LP over the past 4000 years. We found that: (1) The significant increase in population after the Warring States (475–221 BC) was due to increasing cropland area and grain yield as a result of the development of agricultural technology compared to that before the Warring States, but its exponential increasing trend depended on reductions in procreation cost due to tax policies, in particular the abolition of the poll tax. (2) Peasant revolts and wars for power in each dynasty, and military conflicts on the boundary between the farming and pasture areas during the dry and cold period, led to population mortality and migration, causing the population of the LP to show a cyclical pattern of decline with the change in dynasties. (3) The population change of the LP has passed through four major stages: the sparsely populated period of primitive agriculture (2000–476 BC), the population fluctuation period of traditional agriculture (475 BC–1530 AD), the population growth period of traditional agriculture (1531–1949 AD) and the rapid population growth period of modern agriculture (1950–2000 AD).