Organic carbon storage in soils of southeast China

Studies on the quantities and distribution of soil organic carbon in different soil types and soils under different landuses can help to meet our knowledge gaps in estimating the amount of carbon stored in global soils, and provide a scientific basis for assessing the magnitude of management practices on carbon storage. This study was intended to estimate the organic carbon density, distribution and mass in soils of southeast China based on the latest data available. Of the five landuses in southeast China, soils under natural forests have the highest organic carbon density of 11.84 kg m-2, to a depth of about 100 cm, followed by paddy soils (9.72 kg m-2), fruit land soils (7.99 kg m-2) and upland soils (6.38 kg m-2) in order. Soils under natural sparse scrub and grass have the lowest organic carbon density, only about 3.88 kg m-2. The organic carbon density in different soil types, varies from 3.14 to 30.98 kg m-2, with the major zonal soils of latosols, latosolic red soils, red soils, yellow soils and yellow-brown soils having a density between 8.62 and 16.64 kg m-2. Based on this study, the organic carbon stored in soils of southeast China is about 10.6 Gt, constituting about 0.67-0.76% of the world total and about 2.1% of the organic carbon in tropical soils.