Effects Of Cattle And Sheep Mixed-grazing On GHG Fluxes During The Growing Season In Inner Mongolia Desert Steppe

Carbon dioxide (CO2) and methane (CH4) are the main greenhouse gases (GHGs), the increasing of what affected global climate change. Effects of the different grazing systems (cattle grazing, sheep grazing, and mixed-grazing of cattle and sheep) on the fluxes of carbon dioxide (CO2) and methane (CH4) were investigated during the growing season, to evaluate carbon exchange of soil atmospheric affected by grazing system in Inner Mongolia desert steppe, China. The static chamber method was used to measure the fluxes of CO2 and CH4 from June to October in 2013. The results was shown as follows:1. The grazed desert steppe was a net source of soil atmospheric CO2 exchange and a net sink of soil atmospheric CH4 exchange during the growing season. Grazing species did not alter the CO2 or CH4 flux direction.2. CO2 flux in the MG plot (256.66 mg·m-2·h-1)was lower than that in CG (351.18 mg·m-2·h-1), SG (315.38 mg·m-2·h-1), CK(369.95 mg·m-2·h-1)plots. CH4 flux in the MG plot (-0.133 mg·m-2·h-1) was higher than in the CG (-0.112mg·m-2·h-1),SG (-0.116 mg·m-2·h-1), CK (-0.110 mg·m-2·h-1) plots. These findings imply that MG reduced CO2 emission by 26.9%,18.6%,44.14%, and increased CH4 uptake by 18.8%,14.7%,17.29% compared with CG,SG, CK, respectively, in a desert steppe of Inner Mongolia.3. CO2 flux showed out a positive correlation with topsoil temperature (R2=0.540, P<0.01) and moisture (R2=0.523, P<0.01). CH4 flux was a negative correction (R2=0.532, P<0.01) with topsoil moisture.