Diversity of lichen biota of oak forests of the reserve «Vydritsa» (Republic of Belarus, Gomel Region)

As a result of the research, the species composition of lichens and closely related fungi of the oak forest of the reserve «Vydritsa» (Republic of Belarus, Gomel Region) has been revealed. An annotated list, including 113 species has been compiled, 106 of these species are lichens, 6 – non-lichenised saprobic and 1 – lichenicolous fungi. Species Calicium adspersum, Cetrelia olivetorum, Chaenotheca chlorella, Cladonia caespiticia, Lobaria pulmonaria and Parmotrema stuppeum are included in the Red Data Book of Belarus and are listed for the first time for the Svetlogorsk district and the reserve «Vydritsa». The indicator lichens of old-growth oak forests include 20 species; 28 species were recorded in all 12 surveyed localities.

The Estonian Mycological Collections of Heinrich August Dietrich (1820–1897)

Heinrich August Dietrich was a gardener with a deep interest in mycology. He published a two-volume monograph dealing with over 1,000 fungal and fungal-like taxa, the first cryptogamic research of this kind for the Baltic region. Between 1852 and 1857, H. A. Dietrich issued nine volumes of exciccatae named Centuria Plantarum Florae Balticae cryptogamarum. The preserved eight Centuriae and additional collections from Estonia (then the Imperial Russian Baltic province, Estonian Governorate) are revised and their current status in collections is presented. As a result, a new myxomycete species for Estonia, Physarum gyrosum, and the once doubtfully-reported species, Arcyria oerstedii, are recorded, and the earliest vouchers of some endangered ascomycetes, such as Poronia punctata and Sabuloglossum arenarium, are identified in his material. The most remarkable findings among lichenized fungi are Alectoria sarmentosa, Dibaeis baeomyces, Flavoparmelia caperata, Lasallia pustulata, Nephroma laevigatum, Peltigera venosa and Ramalina calicaris, as well as the oldest Estonian specimen of Lobaria pulmonaria.

Findings of new and rare lichen species of Eastern Siberia

The materials of the article contain data on the findings of 13 new species of lichens from Eastern Siberia. Among them, Rhizocarpon chioneum is the species new for Southern Siberia, Peltigera lyngei and Biatora pallens are two new species for the Central Siberian Plateau, six new species are new for the Taymyrskyi Biosphere Nature Reserve (Taimyr Peninsula), Leproplaca chrysodeta, Rhizocarpon chioneum, Rinodina terrestris are new species of lichens for the Republic of Buryatia. The world’s northernmost habitat for the species Bryoria nadvornikiana is reported from the Taimyr Peninsula. New localities for species Leptogium burnetiae, Leptogium hildenbrandii, Lobaria retigera, Lobaria pulmonaria, Nephromopsis laureri, Pyxine sorediata listed in the Red Data Book of the Russian Federation (2008) are noted. New localities for the thirteen species included in the Red Data Books of the Republic of Buryatia, Irkutsk Region, Krasnoyarsk Territory are presented.

Lobaria pulmonaria (L.) Hoffm. in the southwestern Baltic – Kattegat area

The past and present distribution of Lobaria pulmonaria in Denmark, northern Germany, northwestern Poland and nemoral parts of Skåne, Blekinge, southwesternmost Småland and southern Öland (Sweden) has been studied. Of 124 localities visited between 2015 and 2018, L. pulmonaria was confirmed at 64 sites, at each of which its habitat ecology and viability were investigated. It is almost extinct in Schleswig-Holstein, in southern Jutland, on the Danish Islands, in southwestern Skåne, in Mecklenburg-Vorpommern and in the western part of Pomerania. It has disappeared almost completely from areas where mesophytic forests form the potential natural vegetation. The commonest habitats for L. pulmonaria are species-poor acidic beech and species-poor oak forests, and the commonest substrates are trunks of beech, followed by oak. L. pulmonaria specimens on about two thirds of the colonized trees were in a healthy condition. The situation is worst in Schleswig-Holstein and on the Danish Islands, but best in Blekinge and central and northern Jutland. Recent distribution seems to be influenced by both anthropogenic (e.g. air pollution by sulphur dioxide and nitrogen and forestry practices) and natural factors (precipitation, temperature, air humidity), as well as unnatural climatic factors (global warming).

The mycological collection of G. C. Girgensohn from the middle of the 19th century

Since 1844, vouchers of mycological specimens collected from the territory of the historic Baltic provinces of the Russian Empire have been preserved in Estonian natural history collections. A pedagogue and an amateur bryologist, Gustav Carl Girgensohn (1786–1872) compiled a collection of 109 specimens of fungi and myxomycetes sampled from the Livonian Governorate, mostly from the vicinity of Tartu, in years 1844–1859. Girgensohn’s collection, which is kept in the fungarium of the Estonian University of Life Sciences, is introduced here for the first time. Among his specimens there are two notable ascomycetes—coprophilous Poronia punctata (Xylariaceae, Sordariomycetes), recently evaluated in Estonia as Critically Endangered according to IUCN criteria, and Microstoma protractum (Sarcoscyphaceae, Pezizomycetes), recently evaluated as Endangered. The collection’s eleven quite well-preserved specimens of myxomycetes represent six species, the least common of which is Diderma radiatum. In addition, the article introduces nine lichen specimens and one fungal specimen from Girgensohn’s bryophyte collection at the Natural History Museum of the University of Tartu. The most remarkable species among this collection is Lobaria pulmonaria (Lobariaceae, Lecanoromycetes), red-listed and protected in many countries.

MicroCT as a Useful Tool for Analysing the 3D Structure of Lichens and Quantifying Internal Cephalodia in Lobaria pulmonaria

High-resolution X-ray computer tomography (microCT) is a well-established technique to analyse three-dimensional microstructures in 3D non-destructive imaging. The non-destructive three-dimensional analysis of lichens is interesting for many reasons. The examination of hidden structural characteristics can, e.g., provide information on internal structural features (form and distribution of fungal-supporting tissue/hypha), gas-filled spaces within the thallus (important for gas exchange and, thus, physiological processes), or yield information on the symbiont composition within the lichen, e.g., the localisation and amount of additional cyanobacteria in cephalodia. Here, we present the possibilities and current limitations for applying conventional laboratory-based high-resolution X-ray computer tomography to analyse lichens. MicroCT allows the virtual 3D reconstruction of a sample from 2D X-ray projections and is helpful for the non-destructive analysis of structural characters or the symbiont composition of lichens. By means of a quantitative 3D image analysis, the volume of internal cephalodia is determined for Lobaria pulmonaria and the external cephalodia of Peltigera leucophlebia. Nevertheless, the need for higher-resolution tomography for more detailed studies is emphasised. Particular challenges are the large sizes of datasets to be analysed and the high variability of the lichen microstructures.

Gene expression responses to thermal shifts in the endangered lichen Lobaria pulmonaria

Anthropogenic climate change has led to unprecedented shifts in temperature across many ecosystems. In a context of rapid environmental changes, acclimation is an important process as it may influence the capacity of organisms to survive under novel thermal conditions. Mechanisms of acclimation could involve upregulation of stress response genes involved in protein folding, DNA damage repair and the regulation of signal transduction genes, along with a simultaneous downregulation of genes involved in growth or cell cycle, in order to maintain cellular functions and equilibria. We transplanted Lobaria pulmonaria lichens originating from different forests to determine the relative effects of long-term acclimation and genetic factors on the variability in expression of mycobiont and photobiont genes. We found a strong response of mycobiont and photobiont to high temperatures, regardless of sample origin. The green-algal photobiont had an overall lower response than the mycobiont. The gene expression of both symbionts was also influenced by acclimation to transplantation sites and by genetic factors. Lobaria pulmonaria seems to have evolved powerful molecular pathways to deal with environmental fluctuations and stress and can acclimate to new habitats by transcriptomic convergence. Although L. pulmonaria has the molecular machinery to counteract short-term thermal stress, survival of lichens like L. pulmonaria depends mostly on their long-term positive carbon balance, which can be compromised by warmer temperatures and reduced precipitation, and both these outcomes have been predicted for Central Europe in connection with global climate change

Deep divergence between island populations in lichenized fungi

Macaronesia is characterized by a high degree of endemism and represents a noteworthy system to study the evolutionary history of populations and species. Here, we compare the population-genetic structure in three lichen-forming fungi, the widespread Lobaria pulmonaria and two Macaronesian endemics, L. immixta and L. macaronesica, based on microsatellites. We utilize population genetic approaches to explore population subdivision and evolutionary history of these taxa on the Canary Islands, Madeira, Azores, and the western Iberian Peninsula. A common feature in all species was the deep divergence between populations on the Azores, a pattern expected by the large geographic distance among islands. For both endemic species, there was a major split between archipelagos. In contrast, in the widespread L. pulmonaria, divergent individuals were distributed across multiple archipelagos, suggesting a complex evolutionary history involving repeated migration between islands and mainland.