关键词: 土壤有机碳, 复垦土壤, 空间分布, 植被类型, 覆土厚度

Abstract: Abstract :Soil organic carbon (SOC) is a key indicator for characterization of soil quality and ecological characteristics. The study of restoration and distribution of SOC is of great significance for assessing the changes of soil quality and guiding the reconstruction of soil. The selection of gangue-filled reclamation and restoration area in Xinzhuangzi Mine, Huainan City as the research object. the study was divided into 10 sampling plots according to different topsoil cover thickness and vegetation type. The soil samples at 0-20 cm and 20-40 cm soil from different depths of reclaimed soil profile were collected to determine their bulk density(BD), water content (WC),pH value ,and soil organic carbon (SOC). Thus, the authors studied the effect of topsoil thickness and vegetation type on SOCsoil organic carbon (SOC) spatial distribution, and the correlation between SOC and soil physical and chemical properties .The results showed that: (1) The SOC content in different vegetation types was significantly different.In the 20-40 cm topsoil ,the order of SOC content from big to small is that grassland> chestnut woodland> soybean field> corn field> metasequoia forest land. In the 20-40 cm soil, the order of SOC content is from small to large grassland> chestnut woodland> corn field> metasequoia woodland> soybean field . (2) In the 20-40 cm soil layer, the SOC content varies significantly with different soil thickness, and increases with the thickness of the overlying soil layer. The highest value is the sampling area with cover soil of 81-100 cm (4.06 ~ 5.87 g/kg). As the sampling depth increases, the SOC content gradually decreases, and as the thickness of the overlying soil layer deepens, the overall rate of decline is faster. (3) The effect of overlying vegetation type on the SOC content in the study area was greater than that of the soil thickness; there was no significant difference in the content of SOC under the interaction of the existing vegetation type and soil cover thickness in the study area. (4) There has a significant positive correlation between SOC and pH, a significant negative correlation with BD, and a positive correlation with WC (P>0.05).