关键词: 丘状高原, 土壤有机质, 区域分布特征, 影响因素

Abstract: The spatial variability of soil organic matter(SOM) in the Shiqu County was expressed by the spatial analytic approaches such as ordinary kriging(OK) on the basis of the software ArcGIS Desktop 9.0. The results show that the average content of SOM is(134.24±114.46) g/kg, which is far higher than the average level in Sichuan and in the national. The regional distribution characteristics of SOM takes Hongqi and Gemeng as high value center(>200 g/kg), and to the south, west and north three directions gradually takes on decreasing as ring-like or belt-shaped, low value belt(<80 g/kg) distributed in Jinsha river basin. SOM content in soils which is at different altitude, such as <4000 m, 4000~4400 m, 4400~4800 m and >4800 m, is 57.80 g/kg, 185.04 g/kg, 252.48 g/kg and 157.20 g/kg, respectively. The SOM content decreases from surface soil layer to subsoil. Meanwhile, different parent materials, vegetation, topographty and slope lead to the different SOM content levels.

Key words: Hilly Plateau, SOM, regional distribution characteristic, influencing factors