| Wetland ecosystems are one of the three major ecosystem types on Earth that are highly vulnerable to environmental change.The functions of wetlands include climate change,soil and water conservation,and water purification,and it is also influenced by certain factors such as grazing,land use change,and climate change,in which grazing is the main patterns that human beings are using and managing wetlands.Grazing not only changes the coverage type of herbaceous swamp wetlands,but also leads to change in the physical and chemical properties of soil and the living environment of soil microbes in herbaceous swamp wetlands,which in turn influences soil microbes.In herbaceous swamp wetlands,soil microbes(bacteria and fungi)are highly sensitive to environmental changes,and environmental factors in the scenarios of different patterns of grazing utilization management would influence the diversity,community structure,and functional genes of soil microbes.In this sense,Changes in soil microorganisms can be an important influence on environmental change in wetlands.This study was conducted in the lower reaches of the Tumen River in Hunchun City,Yanbian Korean Autonomous Prefecture,Jilin Province,using controlled field experiments to analyse the changes in soil physicochemical properties and wetland soil microorganisms(bacteria and fungi)in herbaceous swamp wetland ecosystems under ungrazed,grazed and short-term grazing bans.The main results of this study are as follows.The main findings of this study are as follows:(1)Soil environmental factors differed somewhat between use management practices,with significant differences(P<0.05)between organic matter(SOM)and total potassium(TK).Cluster analysis revealed that the differences in soil physical and chemical properties between grazing and short term grazing were small and large compared to no grazing;at the same time grazing increased soil p H,phosphorus,total potassium and ammonium nitrogen and changed soil nutrient content;short term grazing had an increasing effect on total nutrient and p H content,not only providing rich nutrients for plant and animal growth,but also regulating soil p H and maintaining soil p H balance.The soil acid-base balance is maintained.(2)Soil bacterial and fungal community types in wetlands did not change significantly between use management practices,sharing the same dominant phylum and genus levels,with phylum level abundance reaching over 80%,bacterial dominant genus level abundance at 5%,and fungal dominant genus level abundance at 30%.The main microbial phyla are Acidobacteria,Proteobacteria,Chloroflexi,Nitrospirae,Ascomycota and Basidiomycetes.there is also some variation in the main indicator species under different utilisation management practices,with 20 species of soil bacteria grazing free,3 species grazing Among the soil fungi there are two species without grazing,two species with grazing and one species with short-term grazing prohibition.(3)Soil bacterial Alpha diversity was greatest under short-term grazing exclusion use management practices,and soil fungal species richness was greatest under short-term grazing exclusion and least under no grazing,with species diversity in the opposite direction.Beta diversity results showed that soil bacterial and fungal communities were more similar under no grazing use management and more dissimilar under short term grazing and grazing use management.(4)Soil water content(SWC)and bulk density(BD)were the main drivers of differences in soil microbial communities under different utilization and management practices(P<0.05).Functional prediction analysis revealed that soil bacteria were mainly metabolic in function under different utilization and management practices;soil fungi were mainly pathotrophic fungi with high pathogenicity under different utilization and management practices,but grazing and short-term grazing exclusion reduced pathogenic fungi,while short-term grazing exclusion also increased saprophytic and symbiotic fungi.In this article,it is clear from controlled experiments that different use management practices influence soil physicochemical properties and thus soil microbial community structure.The results of this study deepen the understanding of the interaction between grazing use and management practices-soil physicochemical properties-soil microorganisms,and provide a theoretical basis for rational grazing and maintenance of wetland ecosystem functions,which is important for the sustainable development of wetlands. |
