Fang Haitao

Wetlands are important for maintaining global ecosystem functions, mitigating global climate change, and regulating regional climate change. Ecological problems caused by global climate change have had serious impacts on plant distribution patterns in the wetlands of riparian zones, as well as on microbial community habitats in the soil. This study was based on a field sampling survey of the distribution characteristics of plant communities in the Ulson River, combined with remote sensing to obtain the spatial distribution pattern of vegetation in the riparian wetland. High-throughput sequencing technology combined with the characteristics of soil physicochemical factors were then used to explore the distribution characteristics of the community structures of soil bacteria and fungi under different vegetation types in the Ulson River Basin, in order to reveal the pattern of changes of soil microbial microorganisms under the different vegetation types in the wetlands of the riparian area and the factors driving those changes. The results showed an obvious banding phenomenon of wetland vegetation in the Ulson River Basin. Proteobacteria ranked first in relative abundance in all the sample plots and were the dominant bacteria in the study area. Ascomycota and Basidiomycota were the dominant fungi in the study area. In swamp areas, degenerate swamp soils, soil moisture content, and soil bulk density affected the microbial richness directly or indirectly by controlling soil nutrients. Plant aboveground biomass was the most significant factor influencing microbial diversity in a typical wet meadow sample. In salinized meadows and swamped meadows, electrical conductivity affected microbial richness and soil bulk density was the main factor influencing microbial diversity. The findings of this study can provide a theoretical basis for the ecological restoration of degraded riparian wetlands and further clarification of soil ecosystem functions in riparian wetlands.

Rapid climate change and human disturbance have caused serious damage and shrinkage of the wetlands in the Mongolian Plateau, posing severe challenges to environmental development. Based on remote sensing images and DEM data, this study established a series of datasets for lakeside wetlands in the Mongolian Plateau in 2000, 2010 and 2020, and investigated the dynamic evolution of lakeside wetlands in the Mongolian Plateau through spatial and temporal analyses. The results showed that in 2000, there were 564 lakes (>1 km2) in the Mongolian Plateau, with a total area of about 55216.47 km2. Compared with 2000, the area of lakes in 2010 was significantly reduced, and there was a significant increase in the number of woody marshes and a reduction in the number of herbaceous marshes. In 2020, the lakes in the central part of the Mongolian Plateau were smaller than in 2010. The areas of lakes in the western, southern and eastern regions were increasing, and the areas of herbaceous swamps, woody marshes and meadows were increasing overall. Lakes, bare land and saline-alkali land decreased overall. The degree of salinization was reduced over the study period. There was a significant correlation between the Adaptive Palmer Drought Index (scPDSI) and lake area. In the past two decades, the climatic factors and human activities of the Mongolian Plateau have profoundly affected the evolution of the lakeside wetlands. We should prioritize the protection of lakes and wetland resources in order to achieve the dynamic balance of wetland ecology.