Abstract: To study the spatial and temporal dynamics of soil carbon pool is one of the important parts of the research on the distribution pattern of forest soil organic carbon along the altitude gradient in the climate transition zone. In order to study the distribution characteristics of typical forest soil organic carbon in the northern subtropical and warm-temperate climate transition zone, 10 sampling points were set up at five different altitudes on the south and north slopes of Guifeng Mountain in easternHubei province with a height difference of 100 meters. Soil samples were collected stratified[0,20)、[20,30)、[30,40) and [40,50)(cm) to measure SOC content and soil physical and chemical properties, and to study the distribution characteristics and influencing factors of SOC. The results indicated that: (1) the surface soil organic carbon content and organic carbon density showed a strong regularity along the altitude gradient, that is, the soil organic carbon content and organic carbon density increased significantly with the elevation (P< 0.01). (2) SOC decreased with the increase of soil depth, but the decreasing amplitude of SOC was different at different soil depth at different altitudes. (3) Correlation analysis showed that there was a significant correlation between soil organic carbon content and soil bulk density and gravel content. The study has an important reference value for the evaluation of soil organic carbon storage and its change characteristics in the northern subtropical mountainous region.

Key words: Guifeng Mountain, northern subtropical region, organic carbon, altitude