Paulina Wietrzyk-Pełka podpisana: Paulina Wietrzyk

This paper contributes to studies on the lichen biota of Arctic glacier forelands. The research was carried out in the moraines of three different glaciers in Svalbard: Longyearbreen, Irenebreen and Rieperbreen. In total, 132 lichen taxa and three lichenicolous lichens were recorded. Eight species were recorded for the first time in the Svalbard archipelago: Arthonia gelidae, Buellia elegans, Caloplaca lactea, Cryptodiscus pallidus,Fuscidea kochiana, Merismatium deminutum, Physconia distorta, and Polyblastia schaereriana. One species, Staurothele arctica, was observed for the first time in Spitsbergen (previously recorded only on Hopen island). All the studied glaciers lie in Spitsbergen’s warm region. However, Kaffiøyra Plain, where Irenebreen is located, is characterized by higher levels of humidity, which may explain its different lichen composition compared to that of the other two moraines. The forelands of Rieperbreen and Longyearbreen are located in the same area of Svalbard, which is also the warmest and the driest and where high species diversity is expected. This proved to be true for the Rieperbreen moraine, but not for the Longyearbreen moraine, where species diversity was lowest. The expansion of tourism along Longyearbyen appears to be a major factor behind the poor development of lichen biota on the Longyearbreen moraine.