Salinification and salt transports under aeolian processes in potential desertification regions of China

China has aeolian and salinization desertification, however, the role of salt transports by wind on salinization processes in potential desertification regions (PDR) is poorly understood. In this study, electrical conductivity of soil saturated extract (ECe), pH values of 1163 surface soil and aeolian transport samples acquired from nine PDRs and the effect of salt transports under aeolian processes on salinification was determined based on wind tunnel experiments. The results show that the maximum ECe values of the surface soils in PDRs such as Hulun Buir, Nunkiang, Horqin, Otindag, Ordos, Qinghai, and Junggar were less than 3 dS/m, and there was low salinization risk and the dominant desertification in these regions was aeolian desertification. Likewise, the ECe values of surface soils in the other regions such as the Ala Shan & Hexi Corridor and Tarim were 2.67 +/- 1.98 and 10.3 +/- 13.13 dS/m, respectively, which show nonsaline and saline soils existence and there is a risk of both aeolian desertification and salinization in PDRs. Annual precipitation is the key factor in salinization controlling in China's PDRs and soil accumulation easier occurred in regions with annual precipitation less than 70 mm due to inadequate leaching. In addition, the wind tunnel experiment results show that under aeolian processes the variability of ECe values of aeolian transports ranged between 2.56% and -15.68%, and the aeolian processes could lower the ECe values of surface soils in most regions. The variability of ECe of the aeolian transports under low free wind speed (14 m/s) and high free wind speed (22 m/s) ranged between -7.87% and 8.77%. Our results highlight that besides the variations in groundwater level, the aeolian processes may play a more important role in salt transports and have exerted potential effects on salinization processes in the region, which may improve decisions in a desertification combating. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study revealed the presence of aeolian and salinization desertification in China's PDR, with varying degrees of salinization risk in different regions. Annual precipitation was identified as the key factor in salinization control. The results highlighted the potentially significant role of wind processes in salt transports and their effects on salinization, providing important insights for desertification combating strategies.