Soil Respiration in a Mixed Oak Forest

For nearly 3 years the soil respiration has been constantly measured in the mixed oak forest of Virelles (near Chimay in Belgium) by the inverted box method of Walter and Haber. The results are presented in relation to the main environmental factors. Seasonal and periodical fluctuations may occur: 1) the maxima, ranging from 2,000 to 3,500 mg C02/m2/day, generally occur in the summer and, the minima, ranging from 500 to 800 mg C02/m2/day, in the winter; 2) minimal soil respiration occurring periodically in short spells during warm weather can be related to the water content of the soil. During the leafless phenological phase a positive correlation was found between the rate of CO2 production and the mean soil temperature at both 1 cm and 10 cm depth; during the leaf phenological phase a positive correlation exists between the rate of CO2 production and the water content of the soil.