Effects Of Precipitation Scenarios And Grassland Management On Soil Respiration In Typical Steppe In Inner Mongolia

Soil respiration(SR)is one of the key processes of carbon cycle in grassland ecosystem.It is not only affected by climate change such as the change of precipitation pattern,but also influenced by the grassland management methods,like grazing,clipping and fencing.However,most of the previous studies on the response of soil respiration to the change of precipitation pattern in grassland ecosystem didn't combine it with the application background of grazing and clipping and so on,which potentially restricted us to understand its response to the change of precipitation pattern deeply and accurately.In this paper,we take the soil respiration of typical grassland in Inner Mongolia as the object.By the control experiments of different precipitation scenarios and grassland management methods lasted for three years,we studied the effects of these experiments on seasonal dynamics and CO2 flux of soil respiration and its components,and whether there is interaction effect between them.Furthermore,we also analyzed the driving factors of soil respiration and its components responding to different precipitation changes and grassland management.As the results show,The seasonal dynamic amplitude of soil respiration and its components increased with the increase of precipitation,while the seasonal dynamics of soil respiration and its components are not significantly different among different grassland management modes.Moreover,The increase of precipitation significantly increased CO2 flux of soil respiration and its components.In contrast,the effects of different grassland management and their interaction on CO2 flux of soil respiration and its components were not strongly but dramatically.And we found that the change of precipitation and grassland management could affect CO2 flux of soil respiration and its components by affecting soil moisture and net primary productivity.Our results indicate that the climate of continuous drought in the typical temperate steppe of Inner Mongolia is the key factor affecting soil respiration.In addition,the significant interaction between precipitation change and grassland management means that the combination of two factors can accurately reflect their impact on soil respiration and its components.