Abstract: In order to clarify the responses of soil basal respiration to temperature changes at different altitudes, and to provide scientific basis for predicting soil carbon dynamics at different altitudes in the future climate change scenarios, the forest soils at different altitudes in Sejila Mountain were studied by laboratory simulated heating experiment. It was shown that soil basal respiration rate and soil accumulated carbon flux increased with the increase of temperature. With the deepening of the soil layer, soil basal respiration rate was decreased. Soil respiration rate of all layers and altitudes increased at first and then decreased with the extension of simulated culture time, while local parts showed a characteristic of concussion change. There was a significant (P<0.01) negative correlation between soil basal respiration rate and culture time, which could be described as exponential function. The cumulative carbon flux of soil basal respiration showed an increasing trend with the prolongation of culture time, and the increases of soil accumulated carbon flux were obvious in the first 14 days, and then gradually became stable. There was a significant (P<0.01) positive correlation between accumulated soil carbon flux and incubation time, which could be described as logarithmic function. In summary, elevated temperature would accelerate carbon emission via surface soil respiration of forest ecosystem.

Key words: Sejila Mountains, forest soil, basal respiration