Abstract:The research was carried out in Xiaoyi open pit coal mine.Soil bulk density,pH value,organic carbon and total nitrogen,as well as the seasonal variations of soil respiration,temperature and water content,were measured under Lotus corniculatus,Medicago sativa,Salix matsudana,Sabina chinensis mixed forest and Pinus tabulaeformis plantations.In addition,the relations of soil respiration to temperature and water content were simulated.Results show that significant differences in soil bulk density,soil organic carbon,ratio of carbon to nitrogen and average annual soil respiration are found under different vegetation types,but not significant in soil pH value and total nitrogen.Seasonal variation of soil temperature shows a single curve over season and correlation for Guassian fitting is significant.Soil water content fluctuates with season.Seasonal variation of soil respiration approximately manifests a single peak,but correlation for Guassian fitting is not significant.Higher regression coefficient is found for the relationship between soil respiration and temperature when fitted with Guassian equation and for the relationships between soil respiration and the two variables of temperature and soil water content with linear and nonlinear equations in M.sativa. And a stronger exponential relationship between soil respiration and water content is found in both L.corniculatus and P.tabulaeformis.