Carbon dioxide in the soils and adjacent caves of the Moravian Karst

Abstract

Variations of soil/cave CO2 concentrations and further variables such as temperature, humidity, and cave visitor attendance were studied in two sites of the Moravian Karst (Czech Republic). All the variables showed the same seasonality; they were strongly correlated with each other. The dependence of soil CO2 levels on soil air temperature and absolute humidity was confirmed. Individual effects could not be distinguished because of multicollinearity. The effect of vegetation on soil CO2 production was not recognized. Cave attendance was identified as the most significant predictor of cave CO2 levels. Other variables, soil CO2 and temperature gradients, were less significant. A spurious relationship was alternatively considered, in which external temperature was the universal predictor of cave CO2 levels.