重庆金佛山岩溶区不同植被条件下土壤-植被系统CO2浓度日变化

对重庆金佛山典型岩溶区林地、裸地表层岩溶生态系统CO2浓度进行短时间尺度变化的野外观测结果表明,林地与裸地不同深处土温变化幅度由地表向土壤深部逐步降低,裸地地表温度和不同深度土温波动幅度均较林地大.林地与裸地各层次土壤CO2浓度变化与土温呈较好的相关关系.林地各层土壤CO2浓度波动微弱,变幅小于裸地.林地与裸地土层中CO2浓度随土层深度增加而增高.植被各层的温度和温度变化幅度从大到小依次为林层、灌层和草层.林层温度最大值滞后于气温约3 h.

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 CO_2 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 CO_2 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.CO_2 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.