摘要：Investigating the contribution of different land use types to the carbon cycle of terrestrial ecosystems is ofconsiderable importance in studying global climate change. The objective of this study is to determine thetemporal variation of soil respiration rates in different land uses (maize, wheat stubble, and bare land) andtheir responses to environmental factors for the Loess Tableland, using an improved multi-channel automaticflux chamber system. Results showed that the soil respiration rate indicates a clear diurnal and seasonalvariations. The mean soil carbon emission rates were 0.94, 1.94 and 2.38 gC·m -2 ·d -1 in bare land, wheatstubble field, and maize field, respectively. The determination coefficient of soil surface temperature on thediurnal soil respiration rate was more significant than that of deeper layers. The Q 10 value was used torepresent the temperature sensitivity of soil respiration in three different land uses, soil respiration in themaize field showed the largest temperature sensitivity. The soil respiration was found to increase exponentiallywith the increase in air temperature, whereas the relationship between soil respiration and soil moisture wasquadratic. The trend of rainfall-affected soil respiration after the sudden rain and continuous light rain showedlarge differences, meanwhile, a clear difference in the sensitivity of soil respiration to rainfall exists for thedifferent land uses.
