Direct-count estimates of fungal and bacterial biovolume in dead leaves of smooth cordgrass (Spartina alterniflora Loisel.)

Two types of hyphal-extraction, direct-count methods of estimating fungal biovalume in standing-dead, autumn leaves of Spartina alterniflora were compared with a clearing+staining method which does not require homogenization. Bacterial biovolume also was estimated, by an acridine-orange direct-count method. Type of homogenization had little effect on measured fungal volume, but counts made using water-soluble-aniline-blue epifluorescence were consistently lower than those made using phase-contrast (by 6-10x). Clearing+staining could not be used to estimate hyphal lengths, but was of use in estimating total ascocarp volume (=0.06 mm³ per mm³ of leaf). Estimated fungal hyphal volume was approximately 0.27 mm³ per mm³ of leaf. Bacterial volume was <3% of fungal volume.