Spatial Distribution And Estimation Of Topsoil Organic Carbon Density In Zhejiang Provine

Soil organic carbon (SOC) library plays an essential role on greenhouse effect and global climate change, as the most important component of the carbon pool in terrestrial ecosystems. Small changes of SOC will affect global climate, and in turn the cultivated topsoil organic carbon is vulnerable to the impacts of natural and human factors, which varies in different scales and regions. Therefore, estimating the cultivated topsoil organic carbon reserves and gaining a good acknowledge of the spatial variation of the SOC hold great significance for the researches on the variation in soil carbon library and carbon sequestration potential.In this study, on the basis of35,488sampling points in Zhejiang province, the Soil Database was established, under the support of a series of GIS tools. Spatial variability and prediction of topsoil SOC reserves and SOC density (SOCD) in Zhejiang province was analyzed to improving the farmland carbon reserves and giving some clues to promote the soil organic matter. The main results and conclusions are as follows:(1) The average topsoil SOCD (0-20cm) is3.46kg/m2, which is above the national average (3.0kg/m2). Black Limestone Soil has the highest SOCD, followed by Hydrogric Paddy Soil, Degleyed Paddy Soil and Red Soil. The farmland topsoil carbon storage of Zhejiang province is94.23×106t.(2) In terms of different cities, topsoil SOCD of Shaoxing city (4.46kg/m2) is the highest. Huzhou, Wenzhou, Ningbo, Hangzhou as well as Jiaxing city were higher than3.50kg/m2. However, the SOCD of Quzhou, Jinhua, Lishui and Taizhou were relatively low, especially ZhouShan (2.75kg/m2), as the lowest city.(3) The topsoil SOCD in northern region of Zhejiang province (Plain area in northern Zhejiang, Hilly basin in eastern Zhejiang and Hilly area in western Zhejiang) was higher than the southern region (Zhejiang hilly basin, the eastern hilly island Plains, Medium mountain area in southern Zhejiang).