高寒山地生态修复方式对土壤颗粒碳氮分配的影响OA北大核心CSTPCD

This study explored the impact of two different ecological restoration approaches on allocations of soil particulate organic carbon and total nitrogen,expecting to provide theoretical references for research on the effects of ecological restoration on the soil carbon and nitrogen pools in alpine mountain regions.By the method of space replacing time,grassland and woodland with different restoration years were selected as research subjects,and the management types were only in the growth season and perennial sealing,respectively.Soil samples collected in the field during the growing season were graded for soil particles by centrifugation in the laboratory,and the soil grain size were classified into sand(50-2000μm),silt(2-50 μm),and clay(<2 μm)to analyze the distribution of organic carbon and total nitrogen in soil particles.The results showed as follows.Firstly,the main subjects of soil particulate organic carbon(POC)and total nitrogen(TN)in grassland and woodland for different restoration years were sand and silt particles,respectively.Soil organic carbon in sand particle in grassland and woodland accounted for 57.36%and 46.46%,respectively;and total nitrogen(TN)in silt particle in grassland and woodland took up 44.79%,and 42.55%,respectively.Second,the percentages of POC and TN in different soil particles all existed significantly positive correlations with their component contents.The allocation of POC and TN in sand was mainly affected by belowground biomass and soil porosity,while the allocation of POC and TN in clay and silt was mainly affected by bulk density and pH.Those results indicated that influences of the afforestation on allocations of the POC and TN in soil different particles were more obvious.