Changes of soil active organic carbon pool under different land use types
不同土地利用类型下土壤活性有机碳库的变化

The measurement of active organic carbon content in 0-40 cm soil layer under different land use types in Shenyang Eco-experiment Station of Chinese Academy of Sciences showed that in 0-20 cm soil layer,the contents of organic carbon(OC),readily oxidizable carbon(ROC),microbial biomass carbon(MBC),dissolved organic carbon(DOC) and light fraction organic carbon(LFOC) were higher in fallow field than in mowing field and bare field,while the content of particulate organic carbon(POC) was relatively higher in mowing field than in fallow field.In 20-40 cm soil layer,the contents of OC,ROC and POC were higher in mowing field,while those of MBC,DOC and LFOC were higher in fallow field.The profile distribution of soil active organic carbon under different land use types appeared a declining trend with soil depth.The allocation proportion of MBC,DOC and LFOC in soil active organic carbon followed the order of fallow field> mowing field> bare field,while that of ROC and POC was in the order of mowing field> fallow field> bare field.The allocation proportion of soil active organic carbon had a declining trend with depth,while that of DOC was in adverse.