CO₂ concentration of the soil vegetation-system under different vegetation covers in karst area of Mt.Jinfo in Chongqing

Variation of carbon fluxes of Epikarst was discovered through observation at Mt.Jinfo in Chongqing on August 15th in the summer of 2002.This investigation aimed at depicting change in CO₂ concentration in Epikarst under different vegetations in summer.Variation of soil temperature was getting smaller in range with the soil depth in both forest land and barren land,but it was smaller in the former than in the latter.Variation of CO₂ concentration was significantly related to soil temperature regimes,showing a similar trend that the variation was smaller in the forest land than in the barren land.CO₂ concentration increased with the soil depth.In terms of soil temperature in different soil layers and variation of soil temperature,soils under different vegetations were lined in the order of forestland>shrubland>grassland.The variation of soil temperature in forestland lagged about 3 hours behind that of the air temperature.