The soil respiration and related correlation factors of an artificial poplar forest in the Horqin Sandy Land-meadow transitional zone and a Caragana microphylla community in a fixed dune were observed in this study using the LI-6400 soil-respiration supporting system. Results demonstrated the following five phenomena. (1) Daily changes in reserved and removed litter from the artificial poplar forest during the growth and late-growth periods have multiple peaks. (2) Seasonal peaks of reserved litter and removed litter appear in August for the artificial poplar forest and the C. microphylla community. Soil respiration of the artificial poplar forest is much higher than that of the C. microphylla community. (3) Seasonal changes of soil respiration in the artificial poplar forest are significantly correlated with the soil temperature (0-10 cm from the surface) (P < 0.01). Changes in the reserved litter are smaller than changes in the removed litter. (4) Seasonal changes of soil respiration of the C. microphylla community are significantly correlated with soil moisture content (0-10 cm from the surface) (P < 0.01). Unlike soil from the artificial poplar forest, changes in the reserved litter are larger than those in the removed litter. (5) The soil respiration of the artificial poplar forest is exponentially correlated with soil temperature, whereas soil respiration of the C. microphylla community has a significant power function relationship with the soil moisture content. By establishing a two-factor regression model of soil respiration (ln R_s) versus soil temperature (T) and soil water content (ln θ), contributions of soil temperature and soil moisture content to reserved litter and removed litter were determined using the normalization method.