Measurement of Microbial Activities in Forest Soil by FDA (Fluorescein Diacetate) Hydrolysis

We developed an easy method of measuring microbial activities in forest soils containing relativelyabundant organic matter by FDA hydrolysis. The values (A490) were assessed as indices of microbialactivities from comparison with cellulose decomposition activities measured in the same soil. The resultsindicated that the A490 values almost reflected cellulose decomposition activities and were approximatelyconstant regardless of season. Hence, it is expected that the relative microbial activities in soils wereeasily detected from only a measurement by this method at any season.