The aim of the present study was to compare the diversity of the fungi in the soil of the "Ilha dos Eucaliptos", located in the dam "Represa do Guarapiranga", in São Paulo, SP, under an Eucalyptus, intermediate and a remaining secundary forest, in March - warm and moist season (summer) and June - cold and dry season (winter) of 1996. The filamentous soil fungi were isolated by the dilution plate and soil plate methods. The similarity among the mycotas was stablished by the index of Sörensen. A total number of 44 fungal taxa (Zygomycota, Ascomycota and mitosporic fungi), distributed in 92 registers was obtained. Twenty fungal taxa (31 registers) were obtained from the Eucalyptus spp. forest, 32 taxa (38 registers) from the intermediate and 16 taxa (32 registers) from the secundary forest. A similarity of 47% was found comparing the soil mycota under Eucalyptus and the intermediate forest, as well as comparing the latter with the mycota of the secundary forest. The similarity between the mycota of the Eucalyptus and the secondary forest was of 39%. In summer the terrestrial mycota was composed by 26 taxa (47 registers) and in the winter by 32 taxa (45 registers), with 46% of similarity between them. The dilution plate method allowed the isolation of 33 fungal taxa (60 registers) and the soil plates 22 taxa (32 registers). Total number of colonies was significantly higher in the soil of the secondary forest, followed by the intennediate and Eucalyptus forest regardless of the climatic conditions. A possible inhibitory effect of the Eucalyptus, forest on the terrestrial fungal community of the island may have been expressed by the decrease of the number of fungal colonies in the soil of the forested site, although the fungal diversity was not affected, remaining high at the three types of vegetation.
terrestrial fungi; vegetation; Eucalyptus; lentic systems