A combined molecular phylogenetic and morphological analysis revealed four species in the genus Tomentypnum. In addition to the commonly accepted widespread T. nitens and North American T. falcifolium, a strong genetic isolation is shown for two taxa. Tomentypnum involutum is elevated from variety to species status; it is widely distributed in permafrost areas in Siberia, the islands of the Arctic Ocean, high mountains in Scandinavia, and is known from the Rocky Mountains of Canada and from Greenland. Tomentypnum vittii is described as a new species for eastern Asia and Siberia, in China and Russia previously referred to T. falcifolium. Descriptions, illustrations, a key for identification, and a map for the Eurasian distributions are provided. Tomentypnum nitens is represented by four groups of haplotypes, which lack morphological distinction, and are therefore referred to one species. However, the distributions of the haplotype groups are revealing; some are more confined to mires rich in relic species composition, whereas others are more widely distributed and partly seem to occur in recently recolonized sites. Different distribution patterns in densely sampled Sweden suggest different glacial and postglacial histories.

Moss floras of xeric calcareous habitats were studied at field sites in Florida, Alabama, Georgia, Tennessee and Kentucky. At each site, one study area was established, including open glade and wooded margin. A species inventory and a community composition investigation were conducted at each study area. Community composition was analyzed for ground-dwelling (soil and rock) and corticolous communities. Ground-dwelling communities were sampled with quadrats, and corticolous communities were sampled by examining trees along the margins. Presence/absence data from the complete species lists from the five sites were used to calculate Jaccard similarity indices among pairs of sites. The frequencies of species occurring in community samples were used to calculate Bray-Curtis similarity indices for ground-dwelling margin and corticolous communities. Jaccard and Bray-Curtis similarities were used in regression analyses to explore their relationship with geographic distance and climatic factors. The total number of species found at each 1 ha study area ranged from 32 to 35. Part of the flora at each site consisted of species common elsewhere in the region, but there were also species commonly associated with calcareous substrates, such as Pleurochaete luteola, Weissia jamaicensis, Orthotrichum strangulatum, Schistidium rivulare and Hyophila involuta. Regression analyses of pairwise similarities and geographic distances showed a strong non-linear correlation between distance and the Jaccard similarities, a somewhat lower correlation between distance and the Bray-Curtis similarities from ground-dwelling margin communities, and little correlation between distance and corticolous community compositions. Multiple regression analyses suggested significant correlations between community variation and temperature and in most cases weaker correlations with precipitation. Our results were notable in that the ground-dwelling community subset exhibited a pronounced distance decay but the corticolous subset did not. This finding suggests that in bryophytes characteristics associated with habitat fragmentation and substrate type have important effects on beta diversity.

In conservation management, outlining critical habitat is an important factor to consider when making recommendations on specific actions. Our study adopts a multi-level approach to determine critical habitat characteristics for boreal felt lichen (Erioderma pedicellatum (Hue.) P.M.Jørg.). The boreal felt lichen in the Avalon Forest Ecoregion of Newfoundland nearly exclusively inhabits balsam fir in old-growth forest stands. However, other factors still need to be determined to better understand what constitutes “critical habitat” in this region, i.e., what are the characteristics of the best quality forest stand for boreal felt lichen? We tested multiple working hypotheses at three levels: 1) at the tree-level, we examined tree morphometrics to determine substrate quality within the lichen habitat; 2) at the plot-level we assessed habitat characteristics and variation in landscape characteristics that can be captured within the 5 m plot radius; 3) we also measured habitat variables beyond the 5 m plot radius, these variables included distance from gaps of various types, elevation and distance from deciduous trees. In our study site, we compared 25 plot pairs, where one plot contained at least one boreal felt lichen thallus and the other contained no thalli. Our findings suggest that characteristics at each level are important when determining critical boreal felt lichen habitat. The tree-level models indicate that boreal felt lichen is likely to occur on trees with a small diameter (5–12 cm). The plot-level models show that north facing slopes are an important habitat characteristic. The beyond-plot analysis suggests an association with distance to deciduous trees, however findings were not consistent with the dripzone hypothesis; perhaps proximity to deciduous trees indicates poor habitat quality. The findings of this study will help streamline future survey efforts and guide important criteria in protecting critical habitat.

A study of Rovno amber revealed two species of liverworts in the genus Frullania (Frullaniaceae, Marchantiophyta) that are new to the Late Eocene flora of Rovno amber. Both species are characterized by the mammillose anterior surface of the ventral lobules. One of these, F. pycnoclada Grolle, was described previously from Eocene Baltic amber, whereas the other species, F. vanae Mamontov, J.J.Atwood, Perkovsky & Ignatov, is described here as new. Frullania vanae differs from F. pycnoclada in the shape of the stem and branch underleaves, the shape of the stem leaf lobules, and in the areolation of the leaf lobe cells.

Eight species of Buellia s.l. containing xanthones are newly reported from China, including two species new to science (Buellia endoflavida and B. microareolata) and six records (B. concinna, B. mamillana, Stigmatochroma gerontoides, Tetramelas chloroleucus, T. geophilus and T. insignis) new to China. The genera Stigmatochroma and Tetramelas are also newly recorded from China. These species share the yellowish thallus with a UV+ yellow to orange reaction and can thus be easily separated from other buellioid taxa. Morphological, chemical and phylogenetic analyses were carried out to elucidate the placement of these species and to support the delimitation of the new taxa. Detailed descriptions and figures for the two new species are given and a key to all xanthone-containing buellioid species from China is provided.

Transplant studies have long been a cornerstone of experimental ecology. Lichens and bryophytes have several useful characteristics for transplantation: they are small, easily transported, and highly responsive to environmental gradients. Here we conduct a systematic review to synthesise lichen and bryophyte transplant studies up until March 2020 (N=454). A great majority of studies (67%) used lichen and bryophyte transplants as biosensors of airborne pollutants. Other research themes such as forest management and biotic interactions were associated with comparably modest bodies of work. A total of 247 lichen and bryophyte species had been used in transplant studies, but four species predominated: Hypogymnia physodes, Pseudevernia furfuracea, Evernia prunastri and Lobaria pulmonaria. Liverworts were only transplanted in 4% of studies, and most studies focused on epiphytic (69%) or terricolous species (31%). A small group of studies (N=15) used whole-community transplants with areas ranging from 25–250,000 cm². Apart from pollution research, studies centered on assisted colonization and simulated climate change appear to be increasing most rapidly in time. There were several recurrent lines of investigation within the included literature (e.g., edge effects, colonization of young forests, climate change effects and local adaptation) and we synthesise the key results. We recommend that future research address underrepresented taxa (e.g., liverworts, biological soil crusts) and geographic gaps, namely Australia and Africa.

In a recent integrative taxonomy study, we verified that the previously accepted concept of Lewinskya affinis (≡ Orthotrichum affine) actually comprises a complex of sibling lineages encompassing both known, accepted species (L. affinis s.str., L. praemorsa and L. tortidontia), recovered synonyms (L. fastigiata and L. leptocarpa), and four species yet unpublished. In the present work, we present detailed descriptions of the previously identified species and the new species, L. scissa from the Canary Islands, and the North American L. arida, L. pacifica and L. pseudoaffinis. In addition, we provide a key to the species in the complex, and discuss the morphological distinction of the species according to geographical areas. All included species are illustrated.

Two lichenicolous fungi are described as new to science from Brazil: Cryptodiscus gassicurtiae on Gassicurtia coccinea from Alagoas, with very small (60–150 µm diam.), grey to brownish apothecia, and Stigmidium anguinellicola on Nyungwea anguinella from Sergipe, without black patches on the host, and ascospores with halo, 8–11 × 3–3.5 µm. Nine further lichenicolous fungi are reported for the first time from Brazil (or from South America). An annotated list is presented of the 78 lichenicolous fungi previously reported from Brazil.

Three new species of Lejeunea (Lejeuneaceae) from Papua New Guinea are described and illustrated herein. They are L. heinarii, L. madangensis and L. marginedentata from Morobe, Madang and Sandaun (West Sepik) province, respectively. They were found growing as epiphytes on trees and inhabit the montane forests of the island. Lejeunea heinarii is characterized by the strongly inflated and inrolled leaf lobules, large reniform underleaves with retuse apices, and well-developed trigones with conspicuous intermediate thickenings (up to 4 per cell), while the distinguishing characters of L. madangensis are the 2-winged perianth keels, large reniform underleaves with cordate-auriculate bases, flat free margin of leaf lobules, and autoicy. Lejeunea marginedentata stood out among all its allies by the inflated perianths without keels, asymmetrical leaf lobes with strong arched dorsal margin and straight ventral margin, and the prominent dentate margin with acute teeth.

Historical and recent material of Bacidia akompsa (basionym: Biatora akompsa) was studied to determine the taxonomic position of this crustose lichen, prompted by the appearance of the provisional name “Lecanactis akompsa (Tuck.) ined.” in multiple online lichen databases and checklists. Initial morphological assessment of verified material confirmed B. akompsa as a member of Arthoniales but distinct from Lecanactis by having epruinose ascomata with a thin exciple open below the hymenium; a pale, K/I+ violet to deep blue hypothecium; and ascospores with a gelatinous sheath. Molecular phylogenetic analysis of specimens recently collected near the type locality revealed B. akompsa to be nested within the genus Pentagenella in Opegraphaceae. The same placement was found using phenotype-based phylogenetic binning with 37 morphological, anatomical and chemical characters. The new combination Pentagenella akompsa is proposed and the species represents the first North American member of this genus, otherwise known only from Chile and Peru. Therefore, our results reveal the genus Pentagenella to have a remarkably disjunct distribution between North and South America. Several specimens previously labeled as Bacidia, Biatora, or Lecanactis akompsa were found to be misidentifications, narrowing the range of P. akompsa to coastal California, where it is found on two coastal conifer species that are (like P. akompsa itself) narrowly endemic and of conservation concern.

Epiphytic lichens directly exposed to atmospheric conditions can help detect how diffuse but pressing global changes may impact regional forest health. For 388 plots in the U.S. Midwest region, we developed indices for climate and air quality based on variation in tree-dwelling macrolichen community compositions (NMS ordination scores), species indicator values, and species environmental optima. Three lichen indices (NMS axis 1 scores, thermophile scores, and climate centroid scores) strongly covaried with thermal and evaporative-demand variables. By contrast, three other indices (NMS axis 2 scores, nitrophile scores and nitrogen centroid scores) were correlated with NH_x (reduced N) deposition. Lichen communities had contrasting responses to different forms of N (NO_x vs. NH_x). Overall, thermal climate variables appeared more influential than air quality in structuring regional communities, based on greater explained variation of community compositions. Richness of species and of potentially adaptive secondary metabolites declined in hot, dry, or NH_x-rich sites. With continued monitoring, significant changes in lichen-community based indices could signal directional shifts in forest vegetation. Changes in the thermophile or nitrophile indices more specifically would indicate the agent and rate of change for forest-altering trends.

Epigloea diversispora is newly described from a coastal mountain summit in western Oregon, U.S.A. The species has minute, shiny, jet black ascocarps appearing on a biofilm of mixed cyanobacteria and algae. The spores are diverse in both shape and septation. Immature spores are initially nonseptate and ellipsoid, then become soleiform, then 1-septate, while mature spores are 3-septate and short fusiform. Lichenization is uncertain, but the species appears to form a loosely lichenized thallus with hyphae dispersed in a partly cyanobacterial and partly algal crust on thin soil, moss, and plant detritus, over rock.