关键词: 江西省, 地貌单元, 土壤有机碳, 空间变异, 尺度效应

Abstract: To study the scaling effect on spatial variation of farmland soil organic carbon in different geomorphic units in Jiangxi Province, using a combined method of classical statistics, geostatistics and a geographic information system, the scale was divided into geomorphic units, county scale corresponding to different geomorphic units and provincial scale. Results show as follows: ① The means of soil organic carbon in farmland was significantly different at different scales but the coefficient of variation was basically unchanged. ② From the county scale to the geomorphic unit, and to the provincial scale, the nugget/sill ratio and range are increasing. ③The spatial distribution level and proportion of soil organic carbon in different scales were significantly different and the spatial distribution in small scale was more abundant. ④Analysis of variance and regression analysis results showed that straw incorporation, parent material, soil type, elevation and soil erosion had a significant influence on the spatial variation of soil organic carbon, but the level between different scale influence degree. Straw incorporation and soil type have not scale effect on the spatial variation of soil organic carbon but parent material, elevation and soil erosion have. The results can provide some reference for understanding the spatial variation of soil organic carbon and estimating the density of soil organic carbon in different scales.

Key words: Jiangxi Province, geomorphic units, soil organic carbon, spatial variation, scaling effect