Abstract
1. The effect of burning upon soil temperature was governed by three factors, i.e., (1) the amount of the burnt fuel (2) the amount of duff layer left unburnt and (3) the extent of the rate of spread. Especially, the effect caused by the former two great. In Zoysia type, Miscanthus type and Sasa type grasslands, the rise of temperature in soil surface reached 10-80℃, 30-170℃ and 5-48℃, respectively. However, soil temperature rapidly fell down near the soil surface and the temperature at several centimeters below the soil surface did not show almost any change. 2. The burning intensity was recorded as 11-155×10^6 (T^2.5t) in Zoysia type grassland, 45-710×10^6 in Miscanthus type grassland and 200-1280×10^6 in Sasa type grassland. The difference in the burning intensity according to the type of grassland was primarily due to the amount of fuel consumed. Besides the above, the extent of the burning intensity was greatly affected by the rate of spread as well as by the type of disposition of fuel. 3. Generally speaking, even the fire with less burning intensity, burnt the above-ground organ of the dominant plant to death. However, even in the case where burning was carred out very successfully, the direct influence of the fire upon plant organ or noxious insects under the ground could not be observed.
