Composition and diversity of endolichenic microfungal communities from saxicolous lichens at Nahal Boker, the central Negev Desert, Israel

We studied the endolichenic fungal communities from saxicolous lichens occupying the cobbles at Nahal Boker, the central Negev Desert, Israel. Overall, 101 species belonging to 64 genera were isolated from 12 lichen species collected in three seasons from the south-facing slope (SFS) and north-facing slope (NFS) of the wadi. The endolichenic communities possessed a set of traits, which helped them to cope with harsh internal and external conditions. It included a prevalence of melanin-containing fungi with thick-walled and multicellular spores and a comparatively high contribution of thermotolerant species and species with meiospore-producing life cycle stage at the more microclimatically severe SFS. Species richness and isolate density of endolichenic communities was the highest in fruticose lichens with thick and wrinkled thalli, and the lowest in endolithic species possessing thin and smooth thalli. The communities from lichens formed a more diverse group than those from surrounding cobbles probably due to the influence of various species of lichens belonging to different growth forms.