Study On The Distribution Characteristics Of Soil Organic Carbon And Aggregates In Different Permafrost Regions Of Daxing'anling

Under the influence of freezing-thawing cycle,the action of soil indirectly affects the physical and chemical and biological characteristics of soil by changing the physical properties of soil structure,particle size and so on.Based on the daxing'anling mountains in permafrost regions,discontinuous permafrost regions,island permafrost regions as the research object,for different types of frozen soil organic carbon and soil aggregate distribution characteristics,analysed and studied,the results are as follows:(1)during the transition from the permafrost zone to the island permafrost zone,the content of soil organic carbon and activated organic carbon is gradually reduced,and the change of vertical structure of soil is that the content of soil organic carbon is higher on the surface than on the bottom.The size of soil carbon reserves is: permafrost regions > discontinuous frozen soil > island frozen soil area,and the soil carbon reserves are mainly distributed within the range of 0 ~ 30 cm.(2)with the in permafrost regions become the island frozen soil area,gradually reduce the content of clay in soil particle size,sand content have increased,the average soil quality diameter value increase.The fractal dimension of soil in permafrost regions is the largest,followed by discontinuous permafrost regions,and the island permafrost regions are the smallest.(3)soil active organic carbon and soil aggregate stability is a significant negative correlation relationship,the soil available nutrients have to the promotion of the stability of soil aggregate,forest density,tree biomass and mean weight diameter has a positive correlation,the increase of vegetation coverage to promote the strengthening of soil aggregate stability.