Effects of Land-use Change on Vertical Distribution and Storage of Soil Organic Carbon in North Subtropical Areas

This paper deals with the effects of land-use change on the vertical distribution and storage of soil organic carbon(SOC) in north subtropical areas by means of field survey.The results showed that:(1)The contents of SOC of the top soil profile(0～10 cm) were the greatest,compared with the other soil profiles(10～100 cm) in the eight land-use types except the tea garden,which showed an increase from 0 to 30 cm and a decrease from 30 to 100 cm in depth.(2)When the natural secondary stands were changed into arable land,the average SOC content decreased by 21.1%,but when changed into the Phyllostachys praecox stands,the average SOC content decreased by 48.5%.In the one meter soil profile,the contents of SOC from the highest to the lowest was ranked as follows: tea garden,shrub,the natural secondary stands,extensive Phyllostachys edulis stands,intensive Phyllostachys edulis stands,masson pines,arable land,Chinese fir,Plyllostachys praecox stands.(3) The vertical distribution of SOC storage showed the same tendency as the SOC content;after the natural secondary stands was converted into arable land,the SOC storage decreased by 22.5%,while converted into Phyllostachys praecox stands,the SOC storage decreased by 51.4%;In the one meter soil profile,the storage of SOC from highest to lowest was ranked as follows: tea garden,shrub,the natural secondary stands,extensive Phyllostachys edulis stands,masson pines,arable land,intensive Phyllostachys edulis stands,Chinese fir and Phyllostachys praecox stands.