Abstract: Soil CO₂ flux is the second largest flux of carbon cycle in terrestrial ecosystems, and its slight variation can result in a significant change in the balance of atmospheric CO₂ concentration. This paper analyzed the effects of soil pH and electric conductivity (EC) on the soil inorganic CO₂ flux, an important component of soil CO₂ flux, in saline/alkaline soils. The experiment was conducted at the Fukang Desert Ecological Station, Xinjiang of Northwest China from June to September, 2010. The inorganic CO₂ flux of nine saline/alkaline soils was differentiated from the soil CO₂ flux by the method of sterilization with high pressure steam chamber. The results showed that for certain saline/alkaline soil, the soil inorganic CO₂ flux was mainly controlled by temperature. Low temperature benefited the CO₂ absorption by the saline/alkaline soils, whereas high temperature benefited the CO₂ release. The soil pH could be used as a good indicator for the soil inorganic CO₂ flux. At low and high temperatures, the effects of the soil pH on the soil inorganic CO₂ flux differed. The soil salinity also had effects on the soil inorganic CO₂ flux, but the effects could be significant only when the soil salinity had a considerable change. This study highlighted the characteristics of soil inorganic CO₂ flux in saline/alkaline soils, which could provide evidence to educe the underlying inorganic mechanisms. The nonnegligible role of soil inorganic CO₂ flux requires further investigation towards a better understanding of soil carbon cycle in saline/alkaline soils in arid lands.

Key words: carbon footprint, high resolution remote sensing, agglomeration., central Liaoning