Distribution Characteristics of Organic Carbon in Main Forest Soil Types in Shenzhen City

Through forest soil survey in 91 sample plots, soil organic carbon content, density and storage of all forest soil types were assessed and their distribution characteristics were therefore analyzed in Shenzhen City. The organic carbon contents among soil types were vastly different, and the order of content was salt swamp soil>yellow soil>red soil>latored soil>seashore sandy soil. The average content of forest soil organic carbon was 7.15g/kg. The soil organic carbon density was salt swamp soil>red soil>latored soil>yellow soil>seashore sandy soil; the average organic carbon density of forest soil was 8.00kg/m². Forest soil carbon content and density declined with the increase of soil depth. The total organic carbon storage of forest soil was 581.01×10⁴ Mg C in which the organic carbon storage of latored soil, red soil, yellow soil, salt swamp soil and seashore sandy soil accounted for 88.77%, 11.45%, 0.43%, 0.33% and 0.02%, respectively; the organic carbon storage in surface soil (0-30cm) accounted for 55.95%. Soil organic carbon content of forest soil was significantly negative correlated with pH value (P < 0.05) and very significantly negative correlated with soil volume weight (P < 0.01).