关键词: 火烧迹地, 土壤有机碳, 土壤微生物生物量碳, 土壤可溶性有机碳

Abstract: The distribution characteristics of soil organic carbon (SOC), soil dissolved organic carbon (DOC) and soil microbial biomass carbon (MBC) under different restorations were studied in Larix gmelinii plantation, Pinus sylvestris var. mongolica plantation, artificial promotion poplarbirch forest and the natural secondary poplarbirch forest restored from burned area after the severe fire of Greater Xing’ an Mountains in 1987. The results showed that the variations in SOC, DOC and MBC ranged from 9.63 to 79.72 g·kg^-1, from 33.21 to 186.30 mg·kg^-1 and from 200.85 to 1755.63 mg·kg^-1, respectively, which decreased with soil depth increasing. There was significant difference in SOC, DOC and MBC among different restorations, with the maximum carbon contents for artificial promotion poplarbirch forest, followed by L. gmelinii plantation, natural secondary poplarbirch forest and P. sylvestris var. mongolica plantation successively. The soil microbial quotient varied from 1.1% under P. sylvestris var. mongolica plantation to 2.3% under artificial promotion poplarbirch forest, and its vertical distributions were different in the four restoration forests. Correlation analysis indicated that MBC had a significant positive correlation with SOC and DOC, respectively. The activity of soil organic carbon in artificial promotion poplarbirch forest was higher than in other forest stands, suggesting a stronger capacity of the soil carbon cycle through natural regeneration with artificial promotion on burned area in Greater Xing’an Mountains.

Key words: burned area, soil dissolved organic carbon., soil organic carbon, soil microbial biomass carbon