To study the variation of soil organic carbon in fractions with the restoration process

we selected the different ages of Pinus massoniana plantations as the research object and take the bare land (CK1) and secondary forest (CK2) as the control

which is basically consistent with the similar management histories in erosive red soil area. The physical and chemical fractionation method was applied

three pools were isolated in soil organic carbon. The active carbon was composed of dissolved organic carbon (DOC) and particulate organic matter (POM); the slow carbon was composed of SOC bound to silt and clay and SOC attached to sand particles or occluded in aggregates; the passive carbon is a chemically recalcitrant fraction. The results showed that

in the process of vegetation restoration (0～30 years)

the storage of active carbon and its distribution proportion in vegetation restoration significantly was improved in the recovery of 7～10 year (P＜0.05)

its storage and distribution remained at a relatively stable level in the vegetation recovery of 27~30 year; the storage of slow carbon and its distribution was significant changes in the recovery of 27～30 year (P＜0.05). The distribution of active carbon pool was decreased

there was significantly correlated between active carbon pool (POM

DOC) and slow carbon pool (P＜0.01)

indicating that the active carbon pool in the recovery gradually transformed to the slow carbon pool after 7～10 year; the stocks of recalcitrant carbon pool continued to increase along with the chronosequences

but its proportion remained relatively stable level. Correlation analysis showed that there was a significant correlation between the chronosequences and the factions with the pools (P＜0.01)

at the same time

the slow carbon pool was the most sensitive in the process of vegetation

indicating that the soil organic carbon in activated carbon accumulation gradually transformed into slow carbon pools accumulation in P. massoniana recovery

thereby affecting the recalcitrant carbon accumulation

which was good for the long-term preservation of soil organic carbon.