火烧对北亚热带杉木林土壤有机碳的影响

[Objective]To study the effect of burning on soil organic carbon and to provide references for post-fire vegetation regeneration. [Method]The changes of organic carbon and nutrient contents in post-fire Cunninghamia lanceolata stand with the soil depth of 0~50 cm in north subtropical areas were analyzed. [Result]The contents of soil total organic carbon (TOC), easily-oxidized carbon (EOC) and light fraction organic carbon (LFOM) were higher than those of contrast sample area, which increased by 1.7%~38.0%、6.6%~33.2% and 3.1%~45.7%, respectively. Significant differences were found in the soil layer with depth of 0~10 cm and 10~20 cm (P<0.01). Compared with the contrast sample area, the soil carbon storage in the layer with depth of 0~50 cm increased by 19.1% one year after burning. The TOC, EOC and LFOM were all significantly related to the soil nutrients (total N, hydrolyzable N and available K). After burning, the increase of TOC, EOC and LFOM were mainly concentrated on the surface of soil and the organic carbon contents increased by 9.22 g·kg^-1 in 010 cm layer. [Conclusion]Moderate intensity burning has a significant impact on organic carbon in the soil of C. lanceolata stand in the north subtropical area. Moderate burning can increase the soil organic carbon because the soil can mix the organic residues caused by incomplete combustion of vegetation layer. Replanting in the burned area could be adopted to promote the vegetation restoration.

Effects of Fire on Soil Organic Carbon of Cunninghamia lanceolata Stands in North Subtropical Area