Response Study Of Soil Microorganisms To Soil Basic Physical And Chemical Properties In Changbai Mountain

Microorganisms exist as decomposers in the earth's biochemical cycle system.Habitat changes can be inferred by mastering the species and quantity changes ofmicroorganisms in a certain period of time.High-throughput sequencing technologywas used to obtain microbial information in top soil of four forest types in ChangbaiMountains.Alpha diversity analysis,dominant species composition and canonicalcorrespondence analysis were used to analyze microbial community changes of fourforest types in Changbai Mountains in combination with basic physical and chemicalproperties of soil during freeze-thaw period.The results showed that:Duiing the freeze-thaw period,the physical and chemical indexes of soluble organic carbon(DOC)?water-soluble total nitrogen(TN),microbial biomass carbon(MBC),microbial biomass nitrogen(MBN),NH4+-N,NO3--N and soil water content(WC)in different forest types were significantly different;the physical and chemical indexes of different forest types were significantly different during tlie freeze-thaw period,and the vegetation differences were significant with the soil physical and chemical indexes.The composition of microorganism community in Pinus koraiensis,QuercusMongolic,Fraxinus mandshurica forest types is similar to that of Secundaria saltus,and the basic physical and chemical properties of soil are similar to the freeze-thawchanges of soil microbial community structure.Fungi are more sensitive toenvironment than bacteria in different forest types of soil during freeze-thaw period,and fungi show higher tolerance than bacteria in freeze-thaw period.The correlationbetween the suitability of fungi and soil physical and chemical properties is higher.Natural freeze-thaw process has a dynamic change on the total number,diversity and species of microbial species in top soil(0-10 cm).Short-term(weekly)freeze-thaw has a significant impact on microbial population,while long-term freeze-thaw has a more significant impact on microbial community.Compared with the late freeze-thawperiod,the effect of early freeze-thaw on microbial population and quantity is smaller,and the diversity and quantity of soil microorganisms in this period are moresignificant.Abundance will fluctuate,but the fluctuation range is small.The abundance and diversity of microorganisms will increase with the increase of MBN and TNcontent in the late freeze-thaw period.During the whole freeze-thaw period,fungi are more suitable for relatively high nutritional environment than bacteria,and fungi aremore sensitive to the freeze-thaw process than bacteria.In the late stage of freezing and thawing,the microbial community changes in soil types of P.koraiensis,Q.Mongolic,F.mandshurica and S.saltus were more obvious than those of Pinus sylvestriformis and Quercus mongolica.