Dynamic closed chamber IRGA method is used to study the relationship between soil respiration and temperature of four deserted grassland communities

i.e.

Artemisia desertorum

Leymus secalinus

Glycyrrhiza uralensis and Agropyron crisatum

in grazing and enclosed plots

and reveal their effects on soil respiration in enclosed plots.The main results are as follows:The diurnal patterns of soil respiration rate in grazing and enclosed plots manifest a single-peak asymmetric curve

and the maximum soil respiration rate occurs at 14:00-16:00. Soil respiration rates in enclosed plots are higher than those in grazing plots

but the significant differences are distinct in the communities of the grazing and the enclosed plots at certain time. The correlation between soil temperature and soil respiration rates at 10 and 15cm depths are higher than that at 5and 20cm depths.At 15cm depth

air temperature is well correlated with soil respiration rate. Be-sides the Artemisia desertorumcommunity

the Q10 values of other plant communities in grazing plots are re-markably lower than those in enclosed plots. The Q10 values are in the order of Artemisia desertorum>Ley-mus secalinus>Glycyrrhiza uralensis> Agropyron crisatum.The Q10 value of Artemisia desertorumcom-munity is greatly above other communities.