The experiment was conducted in the typical terrestrial ecosystem in arid region Sangong River drainage area in Xinjiang (and the selected grassland ecosystem is at Bayinbuluke Grassland) with Fukang Desert. Ecology Experimental Station of Xinjiang Ecological Geography Academic Institution of Chinese Academy of Sciences as the main backing, typical terrestrial ecosystem in arid region as the subject investigated. CO_2 source/sink relation of typical terrestrial ecosystem in arid region is studied ...