Changes in vegetation and moisture in the northern Tianshan of China over the past 450 years

Abstract

Knowledge of historical changes in moisture within semi-arid and arid regions is the basis of climatic change predictions and strategies in response to long-term drought. In this study, a multiproxy peat record with high-resolution from Sichanghu in the northern Tianshan was used to document the changes in vegetation and climate over the past 450 years in the arid Central Asia. The pollen, grain size, and loss on ignition (LOI) records indicate that the productivity of local peat began to increase at ∼1730 AD. The vegetation in the Sichanghu area experienced several transitions, from temperate desert to dense desert, marsh meadow, and steppe desert vegetation. The climate in the study area was extremely dry during the early stages of the Little Ice Age (LIA) (before 1730 AD) and relatively wet during the late stages (1730–1880 AD). The inferred changes in the moisture conditions of the Sichanghu peatland since the LIA may have been controlled by the extent of Arctic sea ice, the North Atlantic Oscillation, and the Siberian High via the connections of large-scale atmospheric circulations such as the Westerlies.