[Estimation of soil organic carbon density and storage in Zhejiang Province of East China by using 1:50000 soil database].

As an important component of the carbon pool of terrestrial ecosystem, soil carbon pool plays a key role in the studies of greenhouse effect and global change. By using a 1:50000 soil database, the organic carbon density in the 0-100 cm layer of 277 soil species in Zhejiang Province was estimated, and the soil organic carbon (SOC) density and storage in the whole Province as well as the spatial distribution of the SOC density and storage in the main soil types of the Province were analyzed. In the whole Province, the SOC density ranged from 5 kg.m-2 to 10 kg.m-2. Among the main soil types in the Province, humic mountain yellow soil had the highest SOC density (52.80 kg.m-2), whereas fluvio-sand ridge soil had the lowest one (1.82 kg.m-2). Red soil and paddy soil had the largest SOC storages, with the sum accounting for 63.8% of the total SOC storage in the Province. The total area of the soils in the Province was 100784.19 km2, the estimated SOC storage was 875. 42 x 10(6) t, and the estimated SOC density was averagely 8.69 kg.m-2. The analysis with the superposition digital elevation model showed that the SOC density presented an obvious variation trend with the changes of elevation, slope gradient, and aspect.