Characteristics Of Soil Organic Carbon And Fungal Community Structure Under Different Vegetation Types In The Yellow River Estuary Wetland

In recent years,carbon cycle has become a hot topic for many scholars because of the increasing environmental problems such as greenhouse effect.Wetlands are one of the three major ecosystems in the world.The carbon accumulation and emission processes of wetlands play an important role in the global carbon cycle.Soil microorganisms are one of the driving factors of carbon cycle.As a key functional group of soil microbial communities,soil fungi have attracted more and more attention.Vegetation type is one of the most important factors affecting soil organic carbon and microbial community structure.In order to understand the effects of vegetation types on the distribution of soil organic carbon and fungal community structure in wetland,the correlation between soil organic carbon and soil fungal community was clarified.In this study,experimental ecology and molecular biology methods were used to investigate the distribution characteristics of different components of soil organic carbon under four different vegetation conditions(Phragmites australis,Suaeda salsa,Tamarix chinensis and bare land)in the Yellow River Estuary wetland.The soil microbial biomass and fungal community structure in different vegetation communities were analyzed,and the response of soil microbial biomass and soil organic carbon accumulation in different vegetation communities was discussed.There were significant differences in total organic carbon(TOC),dissolved organic carbon(DOC),particulate organic carbon(POC)and microbial biomass carbon(MBC)in soils of different vegetation types.Among the four vegetation types,reed community had the highest organic carbon content and bare soil had the lowest organic carbon content.Except for DOC,the other organic carbon contents decreased with the increase of soil depth,which was related to the input of litter in soil surface and the distribution of plant roots.A total of 66phyla,118 classes,154 orders,183 families,226 genera and 305 fungi were detected by sequencing,and 813 OTU sequences were detected.There were significant differences in soil fungi community structure under different vegetation types.Alpha diversity index of soil fungi in Suaeda salsa community was significantly higher than that in other vegetation communities.There was a significant positive correlation between MBC,MBN and SOC,indicating that there was a positive feedback mechanism between soil microbial biomass carbon and soil organic carbon accumulation.In addition to Ascomycetes and Basidiomycetes,Cryptomycetes and Preaxostyla fungi also play an important role in soil organic carbon accumulation and mineralization.The results of this study are of great significance for exploring the mechanism of soil carbon-vegetation-microorganism interaction in the wetland of the Yellow River Estuary.