The Soil Microfungi of Wet-Mesic Forests in Southern Wisconsin

SUMMARYSample populations of the soil microfungi in 5 southern Wisconsin maple-elm-ash floodplain forests were isolated from dilution plates, and lists of the species present and their frequencies of occurrence were compiled. The average number of microfungal species per community was greater here than in any vegetational unit previously surveyed in Wisconsin. A comparatively high proportion of the species encountered were Penicillia—that genus accounting for 43 species (493 isolates) in a total of 199 species (1082 isolates). The species with highest average frequencies were Penicillium paxilli, Paecilomyces carneus, Gliocladium roseum, Penicillium steckii?, P. brevi-compactum?, P. janthinellum, and Penicillium palitans?; these as a group, especially in association with the slightly less common Humicola brevis, Penicillium multicolor, P. crustosum?, and P. herquei, distinguish the soil microfungal populations of the maple-elm-ash floodplain forests from those of prairie and upland forest communities in Wisconsin. However, there were qualitative and quantitative differences in species composition among the stands, particularly between the two stands representing the extremes in vegetational composition. A linear ordination, based on species composition in the 5 sample populations, resulted in an ordering of the stands in the exact sequence dictated when the stands were ordinated on the basis of dominant tree species.