Change of CO_2 Emission from Soil in Loess Tableland Areas of Xi'an

ZHANG Xiao long1, ZHAO Jing bo2,3, MA Run hua4(1. College of Environmental Science and Engineering, Ocean University of China, Qingdao 266003,China; 2. Geographical Department, Shaanxi Normal University, Xi'an 710062, China; 3. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS, Xi'an, 710075, China; 4. Geographical Department, Yantai Normal College of Shandong, Yantai 264025, China)

CO_2 from soil; emission amount; loess tableland; temperature; Xi'an

Through using alkali aqua absorption method, the amount of CO2 emission from soil was observed round the clock in Bailu tableland and Shaoling tableland of xi'an, whose topsoil layer was usually composed of Malan loess. The results showed that there existed apparent diurnal courses of CO2 emission amount in soil under different conditions. CO2 emission amount tended to change similarly with the temperature, but had a retardation time. The amount of CO2 emission in the daytime was less than that at night in loess tableland Soil of Xi'an. Temperature was the most important factor affecting CO2 emission. The emission of CO2 in the soil was sensitive to the texture and structure of soil and More CO2 emitted from loose layers than solid ones, which suggested that the amount of CO2 emission could be regarded as an important index of soil evaluation.