Abstract:In order to understand the effect of re-vegetation on soil active organic carbon, the soil active organic carbon content and distribution in purple soils on sloping-land in Hengyang, Hunan Province, China were studied by using method of spatial series replace time series. The results showed that the content of soil organic carbon (SOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), light fraction organic carbon (LFOC) and readily oxidizable carbon (ROC) were the highest at arbor and frutex stage (P<0.05), and they significantly decreased with soil depth (P<0.05). The ratio of MBC/SOC, DOC/SOC and ROC/SOC significantly increased with the process of re-vegetation (P<0.05). In 0-20 cm soil layer, LFOC/SOC significantly increased with the process of re-vegetation (P<0.05), but that was not obvious change in 20-40 cm soil layer (P>0.05). Along soil depth, LFOC/SOC significantly decreased (P<0.05), DOC/SOC, MBC/SOC and ROC/SOC gradually increased (P>0.05). There were significant positive correlation among SOC, MBC, DOC, LFOC and ROC (P<0.01). All kinds of active organic carbon pool had significant positive correlations (P<0.05 or P<0.01) with soil water content (SWC), total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), and significant negative correlations (P<0.01) with bulk density (BD). Therefore, re-vegetation could enhance at certain degree formation and accumulation of soil active organic carbon and increased soil carbon storage in purple soils on sloping-land in Hengyang.
