The Effects Of Mixed Grazing On Greenhouse Gas Fluxes And Stable Carbon Isotopes

The experiment was conducted in desert steppe of Inner Mongolia Xilamuren grassland from May 2015 to September 2015,attempting to investigate seasonal changes of two greenhouse gas fluxes in the soil,effects of grazing on plant roots and soil carbon isotopes under different grazing treatments?cattle grazing,CG;sheep grazing,SG;cattle,sheep mixed grazing,MG;no grazing,CK?.The study provides a reference for a source of greenhouse gases and carbon stable isotopes.The results of the study are as follows:?1?Different grazing treatments did not change the direction of exchange of greenhouse gases and seasonal changes.Desert grassland showed emission to CO₂and absorbed to CH₄.In the four grazing treatments,the CO₂ emission was CK>CG>SG>MG;the CH₄ absorption was MG>SG>CG>CK.?2?There was a significant positive correlation between soil temperature and CO₂ flux,and soil moisture was negatively correlated with CH₄ flux.?3?The?¹³C_soil in different grazing treatments had the same trend.Compared with CK,the range value of soils in MG,CG and SG all had less.?4?The?¹³C_root of Stipa?Agropyron cristatum?Leymus chinensis and Artemisia frigida under different grazing treatments did not change very much,and they were almost within±2.