Lichens and bryophytes are renowned for their use as bioindicators of environmental pollution and climate change. In urban environments, climate change may directly affect the temperature regime, thereby worsening the intensity of the urban heat island effect (UHI). Using lichens and bryophytes as bioindicators for the UHI allows urban planners and policy makers to mitigate the UHI in a targeted approach. Here, we investigated whether and how the diversity and community composition of epiphytic lichens, algae and bryophytes are influenced by the UHI gradient. We collected species and abundance data on 303 trees from the genus Tilia in three Dutch cities (Amsterdam, Leiden, and Rotterdam) along an UHI gradient. Additionally, abiotic data (relative humidity, temperature, and vapour-pressure deficit) were collected using sensors on 24 trees in Rotterdam. The results show that lichens have a peak in biodiversity in zones where the UHI is intermediate, whereas bryophyte biodiversity increases linearly along the gradient. Furthermore, the biodiversity of epiphytic lichens and bryophytes increases with the age of urban trees. We identified 23 indicators for different zones along the UHI gradient. Their suitability as indicators at the macroclimatic (UHI) level was supported by their microclimatic niche according to the sensor data. Our study, therefore, provides a novel, robust biological framework for developing or refining UHI monitoring in cities.

With ongoing population growth and large-scale urbanization, urban ecosystems are now the predominant habitats for humans. Yet, the biodiversity and dynamics of these ecosystems have been studied only sparsely, especially considering soil microbes. Soils in cities are disturbed and largely covered by (semi-)impervious covering, except in the highly fragmented urban greenspaces. Street trees are one of the smallest and often most confined greenspaces and can serve as a model system to better understand the urban soil microbiome. We used DNA metabarcoding to characterize bacterial and fungal communities in five urban typologies: 1) open soils around street trees (tree pits, Tilia spp.), soils underneath 2) sidewalks and 3) roadways, 4) with and 5) without these trees in five cities in the Netherlands. Bacterial alpha diversity was consistent in all typologies, while fungal richness was 91% higher with street trees nearby and was 304% higher in open tree pits, when compared to typologies without trees. Bacterial and fungal community structure were influenced by soil covering as well as presence of trees consistently throughout the cities. Trait annotation indicates that tree pits harbor more bacteria with putative nitrogen-cycling potential and nearly all putative fungal traits are overrepresented in the presence of trees, implying more functional redundancy. Inferred community assembly differed between typologies: bacterial communities were shaped by homogeneous selection which correlates with sensitivity to edaphic factors, whereas fungal assembly was dominated by dispersal limitation in covered areas, but not in the tree pits. Taken together, street trees have a distinct influence on soil microbial communities, even beneath paving.

Recording the epiphytic lichen flora in Amsterdam on 576 trees distributed over eight common lane tree species shows that the urban epiphytic diversity alone is considerable, representing 15.2%, or 100 species, of the total lichen diversity in the Netherlands. The species recorded include many rarities and some that can be viewed as urban opportunists. Trees bear 15 lichen species on average but are greatly influenced by local factors. Species-specific bark qualities such as water-holding capacity, texture and bark-shedding, influence species richness greatly but are often overshadowed by dominant environmental factors. Tree species with a higher water-holding capacity and texture generally bear the highest species richness. Bark qualities are more indicative of species richness than tree species, showing few significant differences between species richness linked to tree species. Platanus x hispanica is the only observed species whose frequent bark shedding causes it to consistently have the lowest lichen species richness, regardless of environmental factors. In general, bark desiccation and eutrophication are the most dominant factors in influencing urban epiphytic lichen diversity, resulting in xerophytic and nitrophytic lichen species being the most common. Pollution is no longer observed to be the main limiting factor for urban lichen diversity as it was in the past. Instead, bark desiccation associated with the Urban Heat Island (UHI) and low air humidity (drought) is the most damaging factor in contemporary urban conditions in Amsterdam, but it rarely reduces species richness to zero or near zero levels. Areas in which eutrophication and desiccation are much less dominant were repeatedly observed. Such areas sometimes showed local dominance of acidophytes or other distinctive communities. In line with long-term improvements to Dutch air quality, the city now offers a niche to a wider range of species. Three ecological groups (acidophytic, lithophytic-minerotrophic, xerophytic-nitrophytic) are described in this context to characterize reoccurring lichen communities in the city that are indicative of contemporary urban conditions. The term 'lithification' is proposed in an ecological context to describe the frequently observed urban phenomenon of tree bark taking on the properties of rock and consequently bearing lithophytic communities. Additionally, we show the potential use of lichen species and ecological groups to monitor urban climate factors such as the UHI on a very local and accurate scale.

IntroductionThe Macaronesian endemic pleurocarpous moss genus Echinodium comprises three species: E. renauldii (Azores), E. setigerum (Madeira) and E. spinosum (Madeira, Canary Islands). While the generic circumscription of Echinodium has been clarified, species delimitation and relationships, as well as patterns of intraspecific variation, remain insufficiently known.MethodsWe analysed intra- and interspecific differentiation of all three Echinodium species based on phylogenetic reconstructions of DNA sequence data from all three genomes, haplotype networks, and principal coordinates analysis of AFLP fingerprinting data.Key resultsThe Echinodiaceae and Echinodium were resolved as monophyletic. In line with morphological differences, all three Echinodium species were distinguishable from each other. Molecular and morphological data suggested two conflicting relationships, with either E. setigerum and E. renauldii or E. spinosum and E. renauldii being closer to each other. Intraspecific molecular variation, observed in all three species, reflected the geographical isolation of populations, between Madeira and the Canary Islands, the western and central island groups of the Azores, and valleys on Madeira Island.ConclusionsThe molecular data support recognition of three Echinodium species. The patterns observed of molecular and morphological variation do not yet permit conclusions about the relationships and evolutionary origin of these species. Despite the clear geographical separation, the genetic similarity of some western and central Azorean populations may result from dispersal events. Our study adds to accumulating support for a biogeographical distinction between the Azores and Madeira/the Canary Islands for Macaronesian endemic pleurocarpous mosses, which is visible at either the species or intraspecific level.

Global biodiversity loss is accelerating due to the transformation of natural landscapes into agricultural and urban areas. Yet, research on the urbanization impact on environmental and host-associated microbiomes, particularly on the ecological processes that mediate their assembly and function, remains scarce. This study investigated the effects of an urbanization gradient on the diversity and assembly processes of the soil microbiome and the microbiomes of three epiphytic lichen species (Candelaria concolor, Physcia adscendens, and Xanthoria parietina). Our findings revealed that the urbanization gradient shaped the soil microbiome, while the lichen microbiomes exhibited strong host specificity and showed no significant changes in diversity along the urbanization gradient. Heterogeneous selection and dispersal limitation primarily governed the soil community assembly and higher community turnover in medium- and highly urbanized zones compared to low-urbanized zones, indicating an increased influence of environmental pressures, altered resources, and habitat fragmentation in more urbanized areas. The lichen microbiome assembly in each species was primarily governed by undominated processes regardless of urbanization level, indicating that both selection and stochasticity contributed to, but neither dominantly influenced, their assembly. The lichen microbiomes further revealed species-specific co-occurrence networks, with microbial compositional signatures and potential functions being essential for lichen fitness and urban ecosystem health. Taken together, our study contributes to understanding how microbial communities are assembled in urban environments, bridging the gap between conceptual theories and empirical findings in the urban ecology of soil and lichen-associated microbiomes.

Macaronesia is home to several endemic bryophytes, such as Andoa berthelotiana. Recent genetic studies revealed the existence of two intraspecific lineages within this species, one in Madeira and the Canary Islands and another in the Azores. However, patterns of intraspecific variation within archipelagos, remain a relatively unexplored area of research. In this study we investigate patterns of intraspecific variation of Andoa berthelotiana within the Azorean archipelago and potential associations with elevation. Our investigation is based on the analysis of chloroplast DNA sequences and AFLP data. The dataset includes trnL-trnF sequences from 23 samples and AFLP data from 34 samples collected in seven of the nine Azorean islands, encompassing elevations of up to 1200 m. For the DNA sequence data haplotype diversity, nucleotide diversity and a statistical parsimony haplotype network were calculated. The AFLP data were analyzed by AMOVA (Analysis of Molecular Variance) and PCoA (Principal Coordinates Analysis). A Chi-Square test was carried out to assess the significance of the relationship between elevation and AFLP groups or trnL-trnF haplotypes, respectively. The observed intraspecific genetic variation clustered into three trnL-trnF haplotypes and two AFLP groups, without a clear geographical structure across the Azorean archipelago. Group AFLP1 and haplotypes trnL_F1 and trnL_F3 only appeared below 600 m elevation, where low-elevation vegetation (coastal woodlands, lowland forests and montane Laurus azorica forests) prevails, while group AFLP2 and haplotype trnL_F2 occurring along the whole elevational range, but with most samples above 600 m. Associations between elevation and molecular groups were significant according to the Chi-Square test. Our study reveals the presence of genetic variation within Andoa berthelotiana in the Azorean archipelago. The two main genetic groups do not seem to be related to geographical location of islands nor groups of islands, but rather to elevation. One group exhibits a broader ecological amplitude, whereas the other may be genetically adapted to environmental conditions at lower elevations (below 600 m), which includes the area where the native laurel forests dominate and where anthropogenic activities have altered the majority of natural vegetation. Conservation efforts should therefore not only consider the species Andoa berthelotiana itself, which is associated with natural forest, but also intraspecific genetic diversity of Andoa populations, in particular genotypes restricted to lower elevations.

Antarctic ice-free areas are dominated by wind-dispersed organisms. However, which organisms arrive and circulate in Antarctica and how remain poorly understood. Due to their proximity to South America and less extreme conditions, the South Shetland Islands are likely to receive higher diaspore numbers. One possible consequence of climate change is that newcomers will be able to colonize ice-free areas, altering community compositions and impacting the native biota. We used DNA metabarcoding to identify non-fungal eukaryotic DNA present in the air that could potentially reach and circulate in Antarctica. Air was sampled near the Brazilian Comandante Ferraz Antarctic Station on King George Island between December 2019 and January 2020. Sequences representing a total of 35 taxa from 10 phyla and 3 kingdoms were assigned: Chromista (Ciliophora, Cercozoa, Haptophyta and Ochrophyta), Plantae (Chlorophyta, Bryophyta and Magnoliophyta) and Animalia (Mollusca, Arthropoda and Chordata). The most diverse group were the plants (26 taxa), followed by Chromista (6 taxa). The most abundant sequences represented the green algae Chlamydomonas nivalis. The two angiosperm sequences represent exotic taxa; Folsomia is also exotic and was recorded only on Deception Island. Metabarcoding revealed the presence of previously undocumented airborne diversity, suggesting that the Antarctic airspora includes propagules of both local and distant origin.

The Brazilian species of Macromitrium Brid. presents many taxonomic and systematic problems, mainly because the morphological characters used for species identification were not well established in the past, and many species have no phylogenetic position established yet. In this paper, we aim (i) to test the monophyly of Macromitrium based on the phylogenetic analysis of Brazilian species using four markers from different genomic compartments ( trn L-F, rps 4, nad 5 and 26S), (ii) if not a monophyletic group, to delimit which Brazilian species belong to true Macromitrium and, (iii) to test the potential of trn G-R , trn L-F, and ITS markers to resolve the phylogenetic relationships and species delimitations within Macromitrium . Our data demonstrate that Macromitrium is not monophyletic, but split into three different groups: MG1 (true Macromitrium ), MG2 (new genus Pseudomacromitrium ), and MG3 (the monospecific new genus Aureomacromitrium ). Our barcoding data suggest that the best candidate marker for DNA barcoding was trn G-R due to its easy amplification and ability to discriminate all the analyzed species. The nuclear marker ITS was easy to amplify and more variable than the plastid markers, but alignment difficulties and more frequent fungal contaminations are potential drawbacks. Trn L-F had a low discrimination potential. Our results provide important data on the phylogeny of the Macromitrioideae, serving as a basis for the expansion of the phylogenetic studies for the other Macromitrium species that occur in the world, as well as providing a new tool to solve the current problems of identification of Brazilian species.

Increasing evidence indicates that wide distributed bryophyte taxa with homogeneous morphology may represent separate evolutionary lineages. The evolutionary histories of these cryptic lineages may be related to historical factors, such as the climatic oscillations in the Quaternary. Thus, the post-glacial demographic signatures paired with cryptic speciation may result in complex phylogeographic patterns. This research has two aims: to determine whether the widespread moss Racomitrium lanuginosum represents cryptic molecular taxa across the Northern Hemisphere and to infer the effects of Quaternary glaciations on spatial genetic diversity. We used the internal transcribed spacer (ITS) marker to resolve the phylogeographic history of the species and single nucleotide polymorphisms (genotyping-by-sequencing) to infer the genetic structure and demographic history. Finally, we assessed the historical changes in the distribution range using species distribution models. Racomitrium lanuginosum comprises distinct molecular lineages sympatrically distributed in the Northern Hemisphere. We also uncovered long-distance dispersal from eastern North America to Scandinavia and potential in situ survival in northern Scandinavia. Due to the genetic signatures, the Alaska Peninsula could be considered a glacial refugium. The species experienced post-glacial expansion northwards in the Northern Hemisphere, mainly from the Alaska Peninsula. Our results exemplify the complex phylogeographic history in cold environments and contribute to recognizing evolutionary patterns in the Northern Hemisphere.

The high number of bipolar and widespread bryophyte and microbial taxa in the Antarctic flora suggests the effective Long--Distance Dispersal (LDD) of spores and other propagules from lower latitudes and even the Northern Hemisphere to Antarctica and the sub--Antarctic regions. However, few studies have attempted to document the transfer mechanisms by which potential newcomers may arrive in Antarctica. Commonly suggested or assumed mechanisms include transport in air currents, adventitious transfer with migrating or vagrant birds, and with human assistance. In this study, we investigated the biodiversity present in the air along a 40 degrees latitudinal transect, from the port city of Rio de Janeiro, Brazil (ca. 22 degrees S) to Comandante Ferraz Station on King George Island (South Shetland Islands, ca. 62 degrees S), maritime Antarctica, to shed light on the potential role of LDD in species distribution. Air samples were collected in October 2021 on the Brazilian polar support vessel Ary Rongel using air filters with membranes of 0.22 mu m. Total DNA was extracted from the filters and the Internal Transcribed Spacer (ITS2) DNA sequence was used for metabarcoding. A total of 53 non-fungal taxa representing three kingdoms (most abundantly Viridiplantae) and six phyla (most abundantly Bryophyta and Magnoliophyta) were assigned from the sequences found. Aerial biodiversity was greater closer to the coast and generally decreased with increasing latitude, although a small increase was apparent in the South Shetland Islands. The taxa assigned are generally present in coastal biomes, although a small proportion of the assignments represented taxa of more distant origin, supporting the occurrence of LDD in the air column.

The occurrence of species in both polar regions (bipolarity) is a common phenomenon in the Antarctic flora. Considering the high morphological variation in polar regions due to extreme conditions, the use of molecular tools is indispensable for testing whether Arctic and Antarctic populations indeed belong to the same species. However, few phylogeographic studies of bipolar bryophytes have been conducted so far, especially when comparing molecular and morphological variation. Here, we assess the bipolarity and intraspecific variation of Roaldia revoluta, a strictly bipolar species of pleurocarpous mosses. Phylogenetic analyses based on ITS sequences clearly resolve R. revoluta as monophyletic and confirm its bipolar distribution pattern. Low intraspecific molecular variation in the markers ITS/26S and rpl16 was observed, and most specimens from both polar regions belong to a single haplotype, making it difficult to infer the origin and dispersal routes between both polar regions of R. revoluta. Morphometric analysis furthermore suggests that there are no significant morphological differences among populations from both polar regions and that morphological variation is mainly influenced by local environmental conditions. Our data do not unequivocally support the recent separation of the former intraspecific taxon Hypnum revolutum var. dolomiticum at the species level as Roaldia dolomitica.

We studied the community structure and diversity of epiphytic bryophytes in a vertical gradient from tree base to canopy in four lowland rain forest sites of the Colombian Amazon (Amazonas, Caquetá, Putumayo, and Vaupés). Each of the 64 sampled phorophytes was divided into six height zones from the base (Z1) to the outer canopy (Z6). As a subproject, we carried out a genetic population study using the liverwort Cheilolejeunea rigidula (Lejeuneaceae) as our model species, which occurred in all six height zones. In addition to 65 successfully sequenced samples from the study sites, we included individuals of C. rigidula from Guiana and Brazil (Manaus and Tapajos) to investigate the connectivity and genetic structure of this species across the Amazon region and to evaluate the genetic structure based on phorophyte height zones. Each site in Colombia, Brazil and Guiana was considered a subpopulation. The sequenced chloroplast markers (partial atpB gene, partial psbA gene/psbA-trnH spacer) showed little variation across the Amazon and the height zones on the trees. The nuclear marker (ITS) showed a spatial structure indicating genetic differentiation of subpopulations across the Amazon, but little genetic differentiation of C. rigidula along the height of the trees. The gradient across the Amazon shows a relationship between genetic distance and geographic distance, indicating dispersal limitations (P<0.001). At local and regional scales, our results suggest that dispersal can have a dominant effect on populations and communities, increasing connectivity.

Biological particles suspended in the atmosphere have a crucial role in the dynamics of the biosphere underneath. Although much attention is paid for the chemical and physical properties of these particles, their biological taxonomic identity, which is relevant for ecological research, remains little studied. We took air samples at 300 meters above the forest in central Amazonia, in seven periods of 7 days, and used high-throughput DNA sequencing techniques to taxonomically identify airborne fungal and plant material. The use of a molecular identification technique improved taxonomic resolution when compared to morphological identification. This first appraisal of airborne diversity showed that fungal composition was strikingly different from what has been recorded in anthropogenic regions. For instance, basidiospores reached 30% of the OTUs instead of 3–5% as found in the literature; and the orders Capnodiales and Eurotiales—to which many allergenic fungi and crop pathogens belong—were much less frequently recorded than Pleosporales, Polyporales, and Agaricales. Plant OTUs corresponded mainly to Amazonian taxa frequently present in pollen records such as the genera Helicostilys and Cecropia and/or very abundant in the region such as Pourouma and Pouteria. The origin of extra-Amazonian plant material is unknown, but they belong to genera of predominantly wind-pollinated angiosperm families such as Poaceae and Betulaceae. Finally, the detection of two bryophyte genera feeds the debate about the role of long distance dispersal in the distribution of these plants.

Botany is one of the oldest sciences done south of parallel 60 °S, although few professional botanists have dedicated themselves to investigating the antarctic bryoflora. after the publications of liverwort and moss floras in 2000 and 2008, respectively, new species were described. Currently, the antarctic bryoflora comprises 28 liverwort and 116 moss species. Furthermore, antarctic bryology has entered a new phase characterized by the use of molecular tools, in particular DNa sequencing. although the molecular studies of antarctic bryophytes have focused exclusively on mosses, molecular data (fingerprinting data and/or DNa sequences) have already been published for 36 % of the antarctic moss species. In this paper we review the current state of antarctic bryological research, focusing on molecular studies and conservation, and discuss future questions of antarctic bryology in the light of global challenges.

Trindade is a Brazilian oceanic island approximately 1,100 km from the American mainland. The Cyathea Sm. plants from Trindade were originally considered an endemic species, Cyathea copelandii Kuhn & Luerssen, but later included in Cyathea delgadii Sternb. Based on molecular data (trnL-trnF, trnG-trnR and rbcL-accD), morphometric analysis of leaf characters, scanning electron microscopy of indusia and spores, and habitat suitability modeling, the present study confirms the status of C. copelandii as a synonym of C. delgadii. Intraspecific molecular variation suggests phylogeographic structuring in C. delgadii and differentiation between the coastal Atlantic Forest domain and the Cerrado domain (savanna) in the interior of Brazil. The Trindade populations are more closely related to the Atlantic Forest populations, indicating a colonization of the island from the latter area.

The Macaronesian endemic pleurocarpous moss species Andoa berthelotiana occurs in the Madeira, Azores and Canary Islands archipelagos.It has a checkered taxonomic history with placements in different genera or, as monospecific genus Andoa, in different families, most frequently in the Hypnaceae.Earlier molecular phylogenetic analyses indicated a close relationship of Andoa with Ctenidium, Hyocomium and Myurium in a clade corresponding to Myuriaceae, which was supported in the present study based on a larger sampling and markers from all three genomes (chloroplast trnL-trnF, nuclear ribosomal ITS and mitochondrial nad5).Haplotype networks of the nad5 and ITS sequences as well as AFLP fingerprinting data revealed the existence of two intraspecific lineages in Andoa berthelotiana, one occurring in Madeira and the Canary Islands and the other in the Azores.The trnL-trnF haplotype network contradicts this geographic pattern, however, the position of the two mutations differentiating the trnL-trnF haplotypes suggests that they may not be phylogenetically informative.A detailed morphological analysis of plants from the Azores and Madeira indicates the existence of distinguishing characters that correspond with the two molecular lineages.However, the considerable morphological overlap observed would hamper the identification of specimens if both lineages were formally described as separate taxa.We therefore suggest treating the two lineages of Andoa as semi-cryptic species.

Research on bryophyte biology has made exciting advances during the last 10 to 15 years since the publications of Goffinet & Shaw (2008) and Frey & Stech (2009) that summarized the knowledge of the field. New fossils provided insights into past bryophyte diversity and integrative taxonomic approaches combine the ever increasing molecular data with thorough assessments of morphology and anatomy. Patterns of speciation, diversity at population level and geographic distributions are becoming better understood, and the interactions of bryophytes with their biotic and abiotic environment are increasingly being revealed. Nevertheless, important knowledge gaps remain, and anthropogenic threats such as habitat alterations and global climate change on bryophyte diversity increase the urgency of further research.