| With the rapid development of urbanization,the land use changes had been intensified, which affected soil organic carbon stock. To explore how urbanization effected on soil carbon sequestration, taking Shanghai as example, which was the most rapid development of urbanization in China, the second soil survey data of Shanghai,the farmland survey data in Shanghai between the year 2004 and the year 2005,and the field sampling in the year 2009 were used to analyze the variation characters of soil organic carbon. It was found that the average content of soil organic carbon did not change significantly, but the soil organic carbon pool decreased.Thereby, the soil worked as a kind of carbon source, rather than carbon. It was the obvious features of the urbanization to land use changes that the planting structure changed from rice fields to dry land crops for planting vegetable,fruit,and seedlings in some suburban areas.While the organic carbon contents of paddy soil were higher than that of forest and vegetable garden, so planting structure changes had a major impact on soil organic carbon content. Meanwhile, farming systems, tillage pattern, fertilizer and other agricultural management practices also influenced the changes of soil organic carbon content. As far as the urban green space,it did not make up the loss of soil organic carbon lead by urbanization. |
