Toward the first Red List of Latvian lichens according to the IUCN criteria

Abstract

Lichens are well-known bioindicators and exhibit high sensitivity to environmental changes due to their unique biological characteristics. Despite their ecological significance, lichens are often overlooked in conservation policies both at the European Union (EU) and global levels. The situation is better at the level of national Red Lists that can provide candidate species for regional or global Red Lists, thereby helping to prioritize conservation efforts. To fill a gap at the national level, this article presents the comprehensive data of the Red List of Latvian lichens. For the first time, IUCN threat categories and criteria were applied to assess 85 lichenized and one lichenicolous fungus during 2022–2023. Of these species, 3 were classified as Least Concern (LC), 2 as Data Deficient (DD), 11 as Near Threatened (NT), and 68 were ascribed the threatened categories: 14 to Vulnerable (VU), 27 to Endangered (EN), 27 to Critically Endangered (CR). The majority of Latvian lichens categorized as threatened or near threatened inhabit woodlands, particularly old-growth forests, which face the primary threat of intensive forest management. This article emphasizes the importance of continued evaluation efforts, while also addressing challenges associated with data scarcity and limited lichenological research capacity in Latvia.