Abstract: With incubation test, this paper studied the mineralization rate and cumulative mineralized amount of soil organic carbon (C), and the correlations of the mineralized organic C with the initial content of soil active organic C in evergreen broadleaved forest and Chinese fir (Cunninghamia lanceolata) plantation in Huitong region of Hunan Province. The results showed that the mineralization rate and cumulative mineralized amount of soil organic C were significantly higher in evergreen broadleaved forest than in Chinese fir plantation. At the 21st day of incubation at 9 ℃ and 28 ℃, the cumulative mineralized amount of soil organic C at the soil depths of 0-10 cm and 10-20 cm in evergreen broadleaved forest was 1.7-2.7 times of that in Chinese fir plantation. The proportion of CO₂-C released from the mineralization of soil organic C was higher in evergreen broadleaved forest than in Chinese fir plantation. There were significant correlations between the mineralized amount of soil organic C and the initial content of soil dissolved organic C and microbial biomass C (P<0.01). The mineralization of soil C increased soil microbial biomass C while decreased soil dissolved organic C, but the increment or decrement was not too great. When the incubation temperature raised from 9 ℃ to 28 ℃, soil C mineralization rate increased 3.1-4.5 times, and less difference was observed in the responses of the mineralization rate to temperature change between broadleaved forest and Chinese fir plantation.

Key words: Thrips palmi, Population growth, Distribution pattern, Sampling technique