Historical (1880s-2000s) impact of wind erosion on wetland patches in semi-arid regions: A case study in the western Songnen Plain (China)

The western Songnen Plain, which is located in a semi-arid region, is one of the most important cultivated regions in China, and it is subject to constant threats from sandy desertification due to wind erosion. Wetland patches between the desert and cultivated regions in the western Songnen Plain capture dust from desert regions and are influenced by regional wind erosion. To evaluate the degree of historical wind erosion and the impact of wind erosion on wetland patches in the western Songnen Plain, we selected four regions along a wind erosion gradient and analyzed the geochemical properties of soils in wetlands and their surrounding typical ecosystems. The results indicate that more dust and sand are deposited in the western wetland patches than in eastern wetland patches and that more than 50% of the soils in the western wetland patches are comprised primarily of sand. Wetland patches in the wetland/desert transitional region act as natural buffers that impede wind-driven desertification, and only 20% of the soils in eastern wetland patches comprise sand. Additionally, increasing farmland area and residential water consumption caused by human activities have also increased wind erosion in the eastern region. Increased wind erosion has caused eastern wetland patches to start capturing dust from surrounding farmland and grassland since the 1920s, and the accumulation rates of typical elements (i.e., Cu, Pb, Zn, P) increased obviously after the 1960s.