Table 1.
Soil organic carbon densities (kg m−2 at a depth where indicated) for urban soils located in different cities.
Figure 1.
Soil sampling points in Yixing city.
Seven sites were selected for impervious-covered soils, and six sites with similar soil parent materials were selected for open soils. Soil samples were collected at 0–20 cm depth.
Table 2.
Initial properties of the urban soil in Yixing obtained from the second Chinese soil survey a (n = 9 except where noted).
Table 3.
Outline description for the urban soils (0–20 cm) selected in our study.
Figure 2.
The concentrations and densities of SOC and TN for the impervious-covered and open soils in Yixing city.
Values are means ± SE, SOC represents soil organic carbon, and TN represents total nitrogen, * P<0.05 (n = 7 for urban impervious-covered soils, and n = 6 for urban open soils).
Figure 3.
The correlations between the densities of SOC and TN for urban soils in Yixing city.
SOC represents soil organic carbon, and TN represents total nitrogen, * P<0.05 (n = 7 for urban impervious-covered soils, and n = 6 for urban open soils).
Figure 4.
Cumulative carbon release (as CO2) from the impervious-covered and open soils during the 28-d incubation.
Data were fitted by the first-order decay model. The bars indicate standard errors (n = 7 for urban impervious-covered soils, and n = 6 for urban open soils).
Table 4.
The first-order decay model (Eq. 2) parameters and coefficients of determination (r2) for carbon mineralization in urban impervious-covered and open soils.