Variations of soil CO2 concentration and pCO2 in a cave stream on different time scales in subtropical climatic regime

•Soil CO2 concentration and stream pCO2 vary consistently on different time scales.•Seasonal variations of stream pCO2 are controlled by temperature and sources.•Storms result in the most dramatic changes of stream pCO2 at short time.•The climate change (more rainfall) increases the dissolution of carbonate rocks.