The present study reports 223 species and three subspecies of lichens from forest rocky communities of mountain Olovgora, which is the highest point of the Vetreny Poyas ridge (Arkhangelsk Region, NW Russia). A total of 82 species are new for the mainland area of Arkhangelsk Region. The species Bryoria glabra has been reported for the first time for European Russia. Two recorded lichen species, Cladonia bellidiflora and Lobaria pulmonaria, are in the Red Data Book of Arkhangelsk Region. The occurrence of old-growth forests, high heterogeneity of conditions, presence of an altitudinal gradient and the proximity to the sea lead to the rich diversity of lichens in this area.

The present study reports 228 species of lichens and lichenicolous or non-lichenized saprobic fungi in Petrozavodsk (Republic of Karelia, Russia). Seven lichen species of Karelian Red Data Book are recorded. Three species are reported for the first time for Karelia: Arthonia fusca (A. Massal.) Hepp, Hypocenomyce caradocensis (Leight. ex Nyl.) P. James & Gotth. Schneid., and Pycnora sorophora (Vain.) Hafellner. 47 species are reported as new to Karelia olonetsensis, 7 species as new to Karelia onegensis (Fadeeva et al., 2007).

Abstract:The present study reports 188 species and 2 subspecies of lichens and allied fungi from forest rocky communities of the hill Muroigora situated in the Arkhangelsk part of the National park "Vodlozersky" (Arkhangelsk Region, NW Russia).

The paper presents the results of the ongoing research of lichen diversity in Arkhangelsk Region of Russia, in Vodlozersky National Park which is the largest protected area in the territory of NW Russia. In total, 155 species of lichens and allied fungi are recorded for the first time for the Arkhangelsk part of the Vodlozersky National Park, and 69 species – for the whole mainland area of Arkhangelsk Region.

A historical lichen collection in the Herbarium of the Botanical Museum, University of Helsinki, collected in the 19 th and 20 th centuries from the territory of Petrozavodsk (Republic of Karelia, Russia) was examined. A revision of 354 herbarium packets containing 674 specimens resulted in a list of 227 species of lichens and lichenicolous or non-lichenized saprobic fungi. Our historical list added 102 new species to the lichen flora of the city, which now contains 330 species. Xylographa trunciseda is a new lichen record for North-Western Russia. Seven species were registered for Karelia for the first time. 40 species are new to the biogeographic province Karelia olonetsensis and four species -to Karelia onegensis.

A detailed study of lichen diversity and estimation of epiphytic lichen cover characteristics on spruce as a key ecosystem component was performed in boreal forests of Karelia (NW Russia). The aims of the present paper are: (1) to study lichen diversity on Norway spruce in the middle boreal forests of southern Karelia (NW Russia), and (2) to estimate the main characteristics of epiphytic lichen cover on spruce trunks and branches. In total, 158 species of lichens and allied fungi were found on spruce, including 108 species on trunks, 78 on branches and 55 on snags. Seventeen species are listed in the Red Data Book of Republic of Karelia. Ten species are new for the biogeographical province Karelia transonegensis and two for the province Karelia onegensis. Twenty-two species are considered old-growth forest indicators. The total epiphytic lichen cover on spruce trees averaged 59% at the trunk base, 12% at a height of 1.3 m above ground level and 61% on branches. Predominantly, only 12 species contributed to the lichen cover of trunk and branches. Despite the predominance of crustose lichens colonising spruce trees, the main epiphytic lichen cover both on trunks and branches was provided largely by foliose species (57% of the total cover). Due to a variety of morphological features, spruce provides diverse microhabitats, which leads to high lichen species richness with different ecological requirements. Spruce trees play a significant role in maintaining the diversity and conservation of rare species.

Lichens are a symbiotic complex of autotrophic (algae, Cyanobacteria) and heterotrophic (fungi) components that have developed during evolution in coastal ecosystems in the process of adaptation of algae and fungi to terrestrial habitats. Lichens are highly adapted to extreme habitats including the littoral (or intertidal) zones of coasts. In this chapter, we present developmental stages of aquatic lichen investigations: freshwater and marine lichens. The issues of species diversity of coastal lichens, their ecology, and adaptations to the coastal marine environment are described. The leading factors affected the epilithic lichen cover of coasts, and freshwater habitats are at a distance from the waterline and substrate characteristics. Substrate characteristics, especially near the waterline, depend on the wave rhythm. On the coasts of freshwater bodies, four zones are recognized based on flooding duration and lichen ecology. Lichen zones of fresh and marine coasts are distinguished by their species composition: on sea coasts halophytes are predominant and on freshwater shoreshydrophilic lichens. Marker species of lichens were identified for each zone. For the littoral zone, the intrazonal structure of lichen flora was shown. In the adaptation of symbiotic organisms, such as lichens, both symbionts take part: mycobiont and photobiont. Morphological and structural adaptations are mainly associated with mycobiont variability: the presence

Thirty-one lichen-forming fungi, 12 lichenicolous fungi, and 5 non-lichenized fungi are reported as new for Arkhangelsk Region; 7 species are new for its mainland area. Micarea fallax is reported for the first time for Russia; M. laeta and M. pusilla are new for the European part of Russia. The second finding of Nicropuncta rugulosa for Russia is recorded; microconidia are first observed in this species. The records of ten species which have been included in the new edition of the Red Data Book of the Arkhangelsk Region (2020) are presented. Nephromopsis laureri from the Red Data Book of the Russian Federation (2008) and Leptogium rivulare from the IUCN Red List are reported for the first time for Arkhangelsk Region.