Czerwona lista porostów zagrożonych w Puszczy Białowieskiej [Red List of threatened lichens in the Białowieża Old-growth Forest]
The first regional list of threatened lichens and allied fungi is presented. The list is a result of investigation studies in the Białowieża Old-growth Forest, best preserved forests in European lowland, located in North-Eastern Poland. The status of threat to the lichen and allied fungi species listed has been determined according to the Red List Categories by IUCN (2001, version 3.1). The data obtained were compared with historical ones. Changes of the species main frequency were used as an additional indicator of their threat status. The Red List includes 135 taxa of lichens, lichenicolous and saprobic fungi, which constitute 33.7% of the local biota and 8.4% of Polish biota. The status of threatened biota has the folowing categories: Regionally Extinct (RE) - 38 taxa, Critically Endangered (CR) - 29, Endangered (EN) - 19, Vulnerable (VU) - 8, Near Threatened (NT) - 9, Least Concern (LC) -11 and Data Deficient (DD) - 21.