Determinants of soil erosion during the last 1600 years in the forest–steppe ecotone in Northern China reconstructed from lacustrine sediments

Abstract

Wind erosion of soil in northern China contributes to the environment of East Asia and even the Northern Hemisphere. It is commonly thought that human-induced grassland degradation determines soil erosion in the semi-arid steppe region. In this study, we revealed determinants of soil erosion during the last ~1600years through analyzing lacustrine sediment from Huangqihai Lake in this region. Our results showed that soil erosion indicated by sediment particle size was enhanced during three periods: 1570–1330cal.yr.BP with warm and dry climate, 1250–1000cal.yr.BP with warm and wet climate, and 470–150cal.yr.BP with cold and dry climate. The common feature of vegetation regimes for enhanced soil erosion was replacement of forest by steppe, suggesting that decline in vegetation cover from forest to steppe, which was attributed to climatic changes, might lead to enhancement in soil erosion. The trend of historical soil erosion did not match the steady increase in historical human population in China and the very short history of massive cultivation in southern Inner Mongolia. In summary, our results supported nature- rather than human-dominated soil erosion in the semi-arid steppe region in north China during the last 1600years.