Abstract
An open-top chamber technique for measuring soil respiration is tested for evaluating how the open-top chamber alters soil microclimate inside the chamber, and how its alteration influences soil respiration measurements. The temporal variation in soil respiration followed the variation in both air and soil temperatures. The high correlation between soil respiration and soil surface temperature inside the chamber indicates that the open-top chamber technique gives a reasonable estimation for the temporal variation in soil respiration. However, there was a parasol effect of the open-top chamber on soil temperature inside the chamber, suggesting that the open-top chamber technique underestimates the soil respiration when used in an irradiated area on a sunny day. The measurement at an open site showed the effect of wind on a temporal variation in soil respiration. Therefore the open-top chamber may be weak in a strong wind condition, and a reasonable estimation may be restricted to the measurements conducted under a closed vegetation. Our study indicates that the open-top chamber technique needs some further improvements.
