Evaluating the influences of measurement time and frequency on soil respiration in a semiarid temperate grassland

Soil respiration (Soil R) is one of the largest CO₂ fluxes from terrestrial ecosystems to the atmosphere. The largely seasonal and daily patterns of Soil R in semiarid grassland ecosystems indicate that measurement time and frequency would have significant influences on the assessment of seasonal soil carbon release. Based on a three-year continuous measurement of Soil R in a semiarid grassland, we found that the Soil R value measured at around 10:00 o'clock local time was the closest to its daily mean, while the value at 14:00 o'clock was found to be the highest daily rate. A measurement frequency higher than every 10 days was necessary for estimating the seasonal Soil R and its temperature sensitivity (Q ₁₀) reasonably. Our study would be useful as guidelines for manual Soil R measurements and model data selection in semiarid temperate grasslands.