A new system was developed to measure CO2 levels in dry grasslands, comparing two methods. The study found that the eddy covariance technique underestimated CO2 levels compared to soil measurements. The researchers also discovered that there are both upward and downward CO2 fluxes in the soil after rain, affecting overall CO2 levels. The upper soil layer contributes significantly to CO2 efflux. By measuring both ecosystem and soil CO2 levels simultaneously, scientists can better understand how CO2 is exchanged between the surface and the atmosphere, reducing uncertainties in CO2 measurements over flat terrains.