Lichens in the primeval forest areas 'Grosser Urwald' and 'Kleiner Urwald' (Rothwald, 'Durrenstein Wilderness Area', Lower Austria, Austria)

The lichen flora of 'Grosser Urwald' and 'Kleiner Urwald', parts of the primeval forest 'Rothwald' in the 'Durrenstein Wilderness Area', Lower Austria was investigated by us in 2015. We recorded 195 taxa, with 180 colonizing bark or wood (including five not lichenized taxa, traditionally collected by lichenologists), 15 growing on limestone and additional three lichenicolous fungi. Including earlier investigations dating back to 1964, the list compilates 324 taxa. The number of epiphytic and epixylic taxa ever recorded in the study area has grown to 274, however during our survey we were unable to find many previously recorded species. Most of the missing taxa are old-growth forest indicators. A table of all lichens recorded so far from Rothwald is given, sorted in columns by authors. - Loxospora cristinae, Micarea soralifera, Porina pseudohibernica, and Sclerophora coniophaea are recorded the first time in Austria. Biatora fallax, B. pontica, Dictyocatenulata alba, Lecidella subviridis, Mycoporum antecellens, Parmelia ernstiae, Peltigera hymenina, Thelidium auruntii, and Thelopsis flaveola are new for the province of Lower Austria. Both our 51 new records of epiphytic or epixylic taxa and the low amount of lichenicolous species indicate, that the whole diversity spectrum is still incomplete.