[Temporal and spatial variations of greenhouse gases concentrations in soils in Karst Stone Desertification Areas in central part of Guizhou Province].

Concentrations of CO2, N2O and CH4 of soil profile in Karst Stone Desertification Areas were measured monthly from June of 2006 to May of 2007. The results indicated that the concentrations of CO2, N2O and CH4 varied from 530.2 to 31512.6, 0.27 to 0.67 and 0.1 to 3.5 microL x L(-1). On the whole, with the increase of soil depth, the concentrations of CO2 and N2O increased, while CH4 decreased. However, in the cold and wet October, November and January, the concentrations of CO2 and N2O decreased with the depth below 15 cm. In contrast, CHR4 had the inverse trend. Soil temperature and moisture were the main factors which had impacts on the temporal and spatial variations of C2O, N2O and CH4 concentrations in soil profile, but the influence impacts were different. The correlation analysis showed that there was positive correlation between CO2 and N2O (r 0.780-0.894, p < 0.05-0.01), while correlation degree was controlled by environmental factors in different months. CH4 concentrations in soil had significantly negative correlation with CO2 concentrations (r = 330, p < 0.01), but correlated with N2O concentrations just in moisture months (r - 0.829- - 0.956, p < 0.05-0.01).