Dune activity history in China's east dunefields over the past millennium

Abstract

Dune activity encompasses both activation and dune stabilization processes, with the former potentially threatening the sustainability of global ecosystems and human societies. Research on historical dune activity has raised concern among environmental scientists and serves as a foundation for assessing recent and future changes in arid and semi-arid ecosystems. Disagreements related to the causes of historical dune activation persist because of the lack of a more detailed dune activity history for China's east dunefields. Based on stratigraphic evidence, historical documents and archaeological discoveries in the Mu Us and Horqin dunefields, this study presents a detailed dune activity history as well as the forcing mechanisms for China's east dunefields as a whole over the past millennium. The results revealed that two episodes of extensive dune activation (from 800 to 940 ce and from 1300 to 2000 ce) occurred in China's east dunefields, accounting for 69% of the past millennium. The proportions of extensive dune activation driven by a cold and dry climate (from 800 to 940 ce and from 1300 to 1730 ce), strong human activity (from 1900 to 2000 ce) and their combined impacts (from 1730 to 1900 ce) were approximately 68%, 12% and 20%, respectively. Thus, China's east dunefields were in a state of extensive dune activation for most of the past millennium, and most extensive dune activation was driven by climate. Local or sporadic dune activation occurred from 940 to 1300 ce and since 2000 ce in China's east dunefields, which was caused by strong human activity.