An Analysis of Fungal Communities Isolated from Fruticose Lichens

The colonization by filamentous fungi of seventeen samples of fruticose lichens belonging to the genera Cladonia and Sterocaulon collected at one site in the southern Black Forest, FRG, has been studied. A total of 506 fungal strain types were isolated: 166 of them were isolated more than once and 62 of these sporulated and were identified to genus or species. The isolates can be assigned to three ecological groups: soil and litter fungi, symbionts or pathogens of higher plants, and apparently specific lichen-inhabiting taxa. Community ordination was done by cluster and principal component analysis using the taxa that accounted for at least 3% of the isolates in at least one sample. The results clearly demonstrate that the thalli of fruticose lichens harbor a great variety of filamentous fungi. They do not appear to be very specific to one host or confined to only one microhabitat. It can be assumed, however, that many of the observed fungi are in some way associated with their hosts and are not only passive random colonizers.