2.4 Data analysis
SIC density and storage(kg m-2) were calculated from soil bulk weight and inorganic carbon content according to the following equation:
(1)
(2)
where SICi (g⋅kg-1) is the SIC contents of the i -cm soil profile, BDi(g⋅cm-3) is the soil bulk density of the i -cm soil profile, and Di (cm) is the soil layer thickness.
SIC sequestration rate (CRS, kg m-2yr-1) is calculated as follows:
(3)
where CSf is the SIC storage in the final year, CSi is SIC storage in the initial year, andt (years) is the interval between year i and yearf . A positive value indicates an increase in the SIC pool, while a negative value indicates a decrease.
All statistical analyses were performed using Origin 2022 and SPSS 23.0.One-way ANOVA followed by the Tukey’s HSD test (P<0.05) was used to compare the effects of vegetation restoration on SIC in the study sites.