Abstract
The ratio of fungal to bacterial biomass (F/B) in the mineral soil of a burned Japanese red pine forest was determined by two different methods, the substrate-induced respiration inhibition (SIRIN) method and the microscopic method. The values of the F/B ratio were 2.4 by the SIRIN method and 9.5 by the microscopic method in the mineral soil of the burned pine forest. Lower F/B ratio in the SIRIN method might be due to the insufficient stimulation of microbial respiration by glucose added to the soil and incomplete suppression of substrate-induced respiration by antibiotics. The F/B ratios determined by the two methods reflected the predominance of the fungal population in a burned pine forest soil, presumably because the fungal population was more successful in the overall competition with the bacterial population in soils with lower available carbon content such as the pine forest soils.
