Abstract:

In order to study the influence of soil organic carbon content by regeneration in typical subtropical plantations, the natural secondary forest in subtropical zone of Dagang Mountains of Jiangxi Province were cutting and regeneration of 4 plantations (Liriodendron chinense, Pinus massoniana, Cunninghamia lanceolata, Alnus-Liriodendron). On the basis of comparative analysis of different update characteristics of soil organic carbon content, and further correlation analysis and stepwise regression analysis were also used to analyze the influence of soil physic-chemical properties on soil organic carbon. Results showed that all regenerations significantly decreased content of soil organic carbon and changed the distribution characteristics compared with the natural secondary forest. The soil organic carbon content in the depth of 0-40 cm all decreased in the order of Liriodendron chinense>Pinus massoniana>Cunninghamia lanceolata>Alnus-Liriodendron. Liriodendron chinense was not conducive to the increase in soil carbon stocks, because it led to enormous reduction of soil organic carbon content comparing with other regenerated plantations. When Liriodendron chinense and Alnus mixed, it significantly narrowed the decline of the organic carbon content and showed a good mixed effect. The regression formula of organic carbon content and soil properties in the depth of 0-20 cm and 20-40 cm were established with high regression estimation precision. The comparison with Beta suggested that soil nitrogen, available iron and alkali-hydrolyzable nitrogen were the leading factors of SOC content variation.