The soil microfungal community of a South Dakota grassland

The soil microfungi of a western South Dakota grassland were quantitatively surveyed using the dilution plate technique. A 250-membered sample yielded 62 taxonomic entities. Principal forms included Acremonium sp. 4407, Aspergillus fumigatus, A. niveus, A. terreus, Chrysosporium pannorum, Fusarium oxysporum, F. solani, Mammaria echinobotryoides, Mortierella gracilis, Paecilomyces marquandii, Penicillium funiculosum, Penicillium janthinellum, Penicillium lilacinum, and Trichoderma harzianum. Comparison to other grassland surveys has revealed that the South Dakota community is most like that from the Pawnee National Grassland in eastern Colorado with less similarity to mycofloras reported for grasslands in Wisconsin and Oklahoma. Aspergillus terreus, A. fumigatus, A. niveus, Fusarium oxysporum, F. solani, Penicillium janthinellum, P. lilacinum, and Mortierella gracilis are prominent in temperate grassland communities worldwide. A slight seasonal trend was detected at the species level. Aspergillus fumigatus and Paecilomyces marquandii were predominant forms in the spring collection while Penicillium janthinellum and Papulospora sp. were present in greatest numbers in the fall. Relative densities for other species indicated that there may be heightened activity in populations of infrequent taxa in the spring. Twenty-seven and 10% of the colonies developing on dilution plates prepared in the fall and spring, respectively, grew from spores.