Aeolian soils on the eastern side of the Horqin Sandy Land, China: A provenance and sedimentary environment reconstruction perspective

Abstract

There are many stabilized sand dunes along the East and West Liao rivers in the eastern side of the Horqin Sandy Land, and they pose a threat to the surrounding ecological environment and the livelihood of inhabitants once the ecological balance is destroyed. In order to explore the sediment provenance, dynamic mechanism and sedimentary environment of these aeolian soils, and to provide assistance in desertification prevention, two aeolian soil profiles and some topsoil samples were collected for grain size, loss on ignition and phytolith analysis in the East and West Liao River and Horqin Sandy Land, respectively. After end-member analysis of the grain size data, it is concluded that the aeolian soil profiles along the East Liao River and West Liao River have similar provenance and dynamic mechanism. The river-floodplain contributes most to the formation of these aeolian soils and then the Horqin Sandy Land and the interior of Eurasia, and the sediments were transported to the river banks by creep, saltation and suspension in different proportions. The Ic index reconstructed by phytolith, combined with the surrounding sedimentary environmental reconstruction records, the climate experienced several warm-wet and cold-dry periods from 7,720 to 400 cal yr BP, and it significantly influenced the percentages of each component of the profile in each period. The research suggests that planting drought-tolerant shrub plants along the rivers to form shrub belts can effectively prevent the transport of aeolian soils along the rivers, and planting trees and grass on the aeolian soils to increase the vegetation cover, combined with publicity and management, is viable for desertification prevention.