An incubational experiment was designed to assess how soil water content affects the respiratoryintensities of litter layers

different soil layers and DOC-removed soil samples.Soil and mixed litter sampleswere taken in 31year Robinia pseudoacaciaforest in Zhifanggou Watershed

Ansai County.The accumulative CO2-release amounts of soil samples and DOC-removed soil samples(100% water content only)at threesoil depths(20

40and 60cm)and in three controlled litter-mixed soil samples(mixed by complex litters

including Robinia pseudoacacialitters and herbage litters)were determined in laboratory under the three soilwater contents of 100%

20% and 2%

respectively.Results showed that the CO2-release levels at the different soil depths were in the order of:20cm >60cm >40cm under the controlled 100% and 20% watercontents.Under the 100% water content and after DOC was removed

the accumulative CO2-release amountof the soil samples at the 20cm depth decreased

but obviously increased for samples at the 40cm soil depthand had no remarkable change at the 60cm soil depth.The accumulative CO2-release amount of complex litter-mixed soil samples was the highest under the 100% water content.The amount of simply Robinia pseudoacacialitter-mixed samples was obviously higher than that of herbage litter-mixed samples under the 20% and 2% water contents

but slightly lower under the 100% water content.The asynchronous effect of water content levels is suggested on the respiratory intensity of the soil layers with different SOC compositions andlitter types.Removed DOC by heavy precipitation from soil subsurface layers can reduce respiratory intensityof surface soil layers.