Objective The carbon stocks of soil organic carbon (SOC) and its active components in different vegetation restoration types and their influencing factors were studied, in order to provide scientific basis and reference for evaluating the ecological restoration effects of different restoration strategies in Chishui River Basin, Guizhou Province.

Method Five typical vegetation restoration types (shrub, evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, Chinese fir forest and bamboo forest) in study area were selected and carbon storage characteristics and influencing factors of soil total SOC and its active components (dissolved organic carbon, DOC; microbial biomass carbon, MBC; easily oxidized organic carbon, EOC) were analyzed.

Result ① The SOC contents of five vegetation types decreased gradually from surface to deep soil layer. The SOC average content and stock in bamboo plantation were significantly higher than those in the other four types (P < 0.05) in 0 ~ 30 cm soil layer. ② The contents of DOC, MBC and EOC in five vegetation types soils had obvious super aggregation. The average soil DOC content in Chinese fir forest was significantly lower than that in other vegetation types in 0 ~ 30 cm soil layer. The mean contents of soil MBC in bamboo forest and shrub were significantly higher than that in the other three vegetation types (P < 0.05). The mean content of soil EOC was the highest in bamboo forest while the lowest value was in shrub. ③ The soil DOC stocks of the five vegetation types ranged from 0.24 to 0.35 t hm⁻², and the difference was no significant (P > 0.05). Soil MBC stock in shrub (0.50 t hm⁻²) was significantly higher than those of other four vegetation types (0.20 ~ 0.40 t hm⁻²) (P < 0.05). Soil EOC stocks in shrub (5.06 t hm⁻²) and coniferous broad-leaved mixed forest (6.24 t hm⁻²) were significantly lower than those in other vegetation types (10.66 ~ 12.81 t hm⁻²) (P < 0.05). ④ Redundancy analysis showed that soil bulk density (BD) had the highest influence on Chinese fir forest. Soil pH and total phosphorus (TP) had the greatest influence in the shrub and the other four indices had the greatest influence in bamboo forest. Correlation analysis showed that organic carbon and its components were positively correlated with TP, total nitrogen (TN), available nitrogen (AN), available phosphorus (AP) and moisture content, but negatively correlated with soil pH and BD (except for MBC and pH).

Conclusion In general, the bamboo forest had better SOC retention ability, and the shrub was beneficial to increase soil MBC content, but the shrub and the coniferous broad-leaved mixed forest had poor EOC enrichment ability. Vegetation, soil depth and soil physical and chemical properties have significant effects on the spatial distribution and storage of SOC.