JOURNAL OF NATURAL RESOURCES ›› 2014, Vol. 29 ›› Issue (7): 1173-1184.doi: 10.11849/zrzyxb.2014.07.008

• Resources Evaluation • Previous Articles     Next Articles

Scaling Effect on Spatial Variability of Soil Organic Carbon in Different Geomorphic Units on the Loess Hilly Region

ZHANG Zhi-xia1, XU Ming-xiang1,2, SHI Chen-di2, QIU Yu-jie2   

  1. 1. State Key Laboratory of Soil Erosion and Dry Land Farming on Loess Plateau, Institute of Soil andWater Conservation, Northwest A & F University, Yangling 712100, China;
    2. College of Forestry, Northwest A & F University, Yangling 712100, China
  • Received:2013-07-09 Revised:2013-09-26 Online:2014-07-20 Published:2014-07-20

Abstract:

The scaling effect on spatial variability of the soil organic carbon (SOC) of cropland in different geomorphic units were studied in Zhuanglang County on the Loess Hilly Region by using a geostatistics method combined with Geographic Inform System (GIS),the scales included county scale, complete geomorphic unit and town scale. The results showed that: 1) Soil organic carbon content was low in different scales on the study area. The order of mean and the variation coefficient of organic carbon content in complete geomorphic unit and town scale was different. 2) As the research scale changed, the impact of natural factors on the variance of SOC did not significantly change in high mountain region, whereas it changed obviously in hilly and gully region where the influence of random factors increased with the decrease of the study area. The rates of nugget to sill were 0.08 and 0.41 respectively in complete geomorphic unit and town scale of hilly region, whereas in the high mountain region they were 0.16 and 0.10 respectively. For example, the smaller the area, the interpolation information about organic carbon content was more abundant. 3) The elevation and soil type were the main influencing factors of SOC spatial variation on the county scale. In gully region, all the factors were not significant between the complete geomorphic units and the town scale. In the hilly region, the main factors were the altitude and the soil type on the complete geomorphic unit scale, but on town scale it was the slope gradient of field surface. In the high mountain region, the main controlling factor was soil type on the geomorphic unit scale, but the town scale was the soil erosion degree.

Key words: Loess Plateau region, soil organic carbon, scaling effect, spatial variability

CLC Number: 

  • S153.6