Soil CO2 is an important part of the global carbon cycle. In karst, it controls fundamental processes as limestone dissolution and calcite speleothem growth. A spatiotemporal distribution of soil CO2 concentrations was studied at the site of Společňák sinkhole and its close vicinity (Harbechy Plateau, Moravian Karst). The aim of the study was testing an effect of subterranean ventilation of the CO2 concentrations in soil profile. At this site, 25 soil boreholes were drilled: each 2 cm in diameter and 60 cm deep. A central drill-hole was situated at the bottom of the sinkhole. Six identical drill-holes, six meters of each other, were in the direction of NE, SW, NW, and SE. As result, 3 drill-holes were placed in sinkhole body and 3 drill-holes outside in the field in every direction. CO2 concentrations were measured directly in the atmosphere of soil drill-holes at a depth of about 10 cm below the surface. Soils were identified as haplic Luvisols. The found CO2 concentrations varied spatially and temporally between 1 188 ppmv and 6 039 ppmv. Statistical analysis showed that the differences between CO2 concentrations in sinkhole and its vicinity are not significant at α = 0.05. The only exception from these results seems to be inconclusive. The differences between the sinkhole CO2 concentrations in summer and winter were found also insignificant. Therefore, we have concluded that the study did not confirm any impact of subterranean ventilation on soil CO2. However, for a definitive confirmation or rejection of the hypotheses about subterranean ventilation, it is needed more comprehensive survey under tighter spatial and temporal sampling at multiple locations.Soil CO2 is an important part of the global carbon cycle. In karst, it controls fundamental processes as limestone dissolution and calcite speleothem growth. A spatiotemporal distribution of soil CO2 concentrations was studied at the site of Společňák sinkhole and its close vicinity (Harbechy Plateau, Moravian Karst). The aim of the study was testing an effect of subterranean ventilation of the CO2 concentrations in soil profile. At this site, 25 soil boreholes were drilled: each 2 cm in diameter and 60 cm deep. A central drill-hole was situated at the bottom of the sinkhole. Six identical drill-holes, six meters of each other, were in the direction of NE, SW, NW, and SE. As result, 3 drill-holes were placed in sinkhole body and 3 drill-holes outside in the field in every direction. CO2 concentrations were measured directly in the atmosphere of soil drill-holes at a depth of about 10 cm below the surface. Soils were identified as haplic Luvisols. The found CO2 concentrations varied spatially and temporally between 1 188 ppmv and 6 039 ppmv. Statistical analysis showed that the differences between CO2 concentrations in sinkhole and its vicinity are not significant at α = 0.05. The only exception from these results seems to be inconclusive. The differences between the sinkhole CO2 concentrations in summer and winter were found also insignificant. Therefore, we have concluded that the study did not confirm any impact of subterranean ventilation on soil CO2. However, for a definitive confirmation or rejection of the hypotheses about subterranean ventilation, it is needed more comprehensive survey under tighter spatial and temporal sampling at multiple locations
