Search

Interactions between organisms are determined by life-history traits. Ecological strategies regarding species specialisation range from generalist to highly specialised relationships. Although it is expected that habitat fragmentation's effect on species abundance and survival depends on their degree of specialisation and life-history traits, few studies have delved into the interplay between interaction specialisation, life-history traits and habitat fragmentation.Here, we investigate the combined effect of habitat fragmentation, forest structure and life-history traits (growth form and reproductive mode) on the specialisation of lichen-forming fungi (mycobionts) toward their photosynthetic partners (photobionts) in lichen symbioses.We studied mycobiont specialisation in epiphytic lichen communities present in 10 fragments of Quercus rotundifolia forest embedded in an agricultural matrix. Both mycobionts and photobionts were identified DNA barcoding and mycobiont specialisation was measured through interaction parameters calculating the relative number of interactions (normalised degree; ND) and the specialisation of each species based on its discrimination from a random selection of partners (d'). Phylogenetic generalised linear mixed models were used to analyse the effect of patch size as well as the life history traits growth form (crustose, foliose, fruticose) and reproduction mode (sexual vs. asexual) on mycobiont specialisation.Both mycobiont and photobiont richness along the patch size gradient followed a hump-back pattern, which was more pronounced in photobionts. Mycobionts forming crustose thalli established the largest number of interactions. Mycobiont specialisation (d') was larger for fruticose and foliose forms and species with vegetative reproduction. Along the gradient of fragment size, the relative number of interactions decreased and the specialisation of mycobionts with vegetative reproduction increased.Synthesis. The study of mycobiont specialis

Phenotypic variability is a successful strategy in lichens for colonizing different habitats. Vagrancy has been reported as a specific adaptation for lichens living in steppe habitats around the world. Among the facultatively vagrant species, the cosmopolitan Cetraria aculeata apparently forms extremely modified vagrant thalli in steppe habitats of Central Spain. The aim of this study was to investigate whether these changes are phenotypic plasticity (a single genotype producing different phenotypes), by characterizing the anatomical and ultrastructural changes observed in vagrant morphs, and measuring differences in ecophysiological performance. Methods Specimens of vagrant and attached populations of C. aculeata were collected on the steppes of Central Spain. The fungal internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GPD) and the large sub-unit of the mitochondrial ribosomal DNA (mtLSUm), and the algal ITS and actin were studied within a population genetics framework. Semi-thin and ultrathin sections were analysed by means of optical, scanning electron and transmission electron microscopy. Gas exchange and chlorophyll fluorescence were used to compare the physiological performance of both morphs. Key Results and Conclusions Vagrant and attached morphs share multilocus haplotypes which may indicate that they belong to the same species in spite of their completely different anatomy. However, differentiation tests suggested that vagrant specimens do not represent a random sub-set of the surrounding population. The morphological differences were related to anatomical and ultrastructural differences. Large intercalary growth rates of thalli after the loss of the basal–apical thallus polarity may be the cause of the increased growth shown by vagrant specimens. The anatomical and morphological changes lead to greater duration of ecophysiological activity in vagrant specimens. Although the anatomical and physiological changes could be chance e, Ministerio de Ciencia e Innovación, Gobierno de España, German Science Foundation, Depto. de Farmacología, Farmacognosia y Botánica, CAI Ciencias de la Tierra y Arqueometría, TRUE, pub

The green algal lichen Placopsis pycnotheca was identified at Pia and Marinelli glaciers (Isla Grande of Tierra de Fuego, Chile) as a primary colonizer of bare soil in areas close to the front of the glacier or around small ponds created after glacier retreatment. Electron microscopy study showed that P. pycnotheca formed a thick hypothallus within which hyphae and their extracellular polymeric substances bind numerous soil particles. This structure augments water holding and soil stabilization capacities and constitutes an early stage in soil crust development. In addition, numerous cephalodia are formed within the hypothallus and subsequently develop upwards towards the thallus surface, sometimes before the formation of squamules with green algae. These anatomical and morphological strategies together with physiological properties such as the long photosynthetic activity period (measured in the laboratory) help explain its pioneering role as a colonizer and its apparently high growth rate., Ministerio de Ciencia e Innovación, Gobierno de España, Depto. de Farmacología, Farmacognosia y Botánica, Fac. de Farmacia, TRUE, pub

This study explores the diversity of photobionts associated with the Mediterranean lichen-forming fungus Cladonia subturgida. For this purpose, we sequenced the whole ITS rDNA region by Sanger using a metabarcoding method for ITS2. A total of 41 specimens from Greece, Italy, France, Portugal, and Spain were studied. Additionally, two specimens from Spain were used to generate four cultures. Our molecular studies showed that the genus Myrmecia is the main photobiont of C. subturgida throughout its geographic distribution. This result contrasts with previous studies, which indicated that the main photobiont for most Cladonia species is Asterochloris. The identity of Myrmecia was also confirmed by ultrastructural studies of photobionts within the lichen thalli and cultures. Photobiont cells showed a parietal chloroplast lacking a pyrenoid, which characterizes the species in this genus. Phylogenetic analyses indicate hidden diversity within this genus. The results of amplicon sequencing showed the presence of multiple ASVs in 58.3% of the specimens studied.

Ramalina farinacea is an epiphytic lichen-forming fungus with a broad geographic distribution, especially in the Northern Hemisphere. In the eighties of the last century, it was hypothesized that R. farinacea had originated in the Macaronesian–Mediterranean region, with the Canary Islands as its probable southernmost limit, and thereafter it would have increased its distribution area. In order to explore the phylogeography of this emblematic lichen, we analyzed 120 thalli of R. farinacea collected in 38 localities distributed in temperate and boreal Europe, the Western Mediterranean Basin, and several Macaronesian archipelagos in the Atlantic Ocean. Data from two nuclear markers (nrITS and uid70) of the mycobiont were obtained to calculate genetic diversity indices to infer the phylogenies and haplotype networks and to investigate population structure. In addition, dating analysis was conducted to provide a valuable hypothesis of the timing of the origin and diversification of R. farinacea and its close allies. Our results highlight that phylogenetic species circumscription in the “Ramalina farinacea group” is complex and suggests that incomplete lineage sorting is at the base of conflicting phylogenetic signals. The existence of a high number of haplotypes restricted to the Macaronesian region, together with the diversification of R. farinacea in the Pleistocene, suggests that this species and its closest relatives originated during relatively recent geological times and then expanded its range to higher latitudes. However, our data cannot rule out whether the species originated from the Macaronesian archipelagos exclusively or also from the Mediterranean Basin. In conclusion, the present work provides a valuable biogeographical hypothesis for disentangling the evolution of this epiphytic lichen in space and time.

The development of diagnostic methods to accurately assess the effects of treatments on lithobiont colonization remains a challenge for the conservation of Cultural Heritage monuments. In this study, we tested the efficacy of biocide-based treatments on microbial colonization of a dolostone quarry, in the short and long-term, using a dual analytical strategy. We applied a metabarcoding approach to characterize fungal and bacterial communities over time, integrated with microscopy techniques to analyze the interactions of microorganisms with the substrate and evaluate the effectiveness. These communities were dominated by the bacterial phyla Actinobacteriota, Proteobacteria and Cyanobacteria, and the fungal order Verrucariales, which include taxa previously reported as biodeteriogenic agents and observed here associated with biodeterioration processes. Following the treatments, changes over time in the abundance profiles depend on taxa. While Cyanobacteriales, Cytophagales and Verrucariales decreased in abundance, other groups, such as Solirubrobacteriales, Thermomicrobiales and Pleosporales increased. These patterns could be related not only to the specific effects of the biocide on the different taxa, but also to different recolonization abilities of those organisms. The different susceptibility to treatments could be associated with the inherent cellular properties of different taxa, but differences in biocide penetration to endolithic microhabitats could be involved. Our results demonstrate the importance of both removing epilithic colonization and applying biocides to act against endolithic forms. Recolonization processes could also explain some of the taxon-dependent responses, especially in the long-term. Taxa showing resistance, and those benefiting from nutrient accumulation in the form of cellular debris following treatments, may have an advantage in colonizing treated areas, pointing to the need for long-term monitoring of a wide range of taxa. This study

Lichens thrive in rocky coastal areas in temperate and cold regions of both hemispheres. Species of the genus Lichina, which form characteristic black fruiting thalli associated with cyanobacteria, often create distinguishable bands in the intertidal and supralittoral zones. The present study uses a comprehensive specimen dataset and four gene loci to (1) delineate and discuss species boundaries in this genus, (2) assess evolutionary relationships among species, and (3) infer the most likely causes of their current geographic distribution in the Northern and Southern hemispheres. A dated phylogeny describes the time frame in which extant disjunctions of species and populations were established. The results showed that the genus is integrated by four species, with Lichina pygmaea, L. confinis and the newly described L. canariensis from rocky seashores in the Canary Islands, occurring in the Northern Hemisphere, whereas L. intermedia is restricted to the Southern Hemisphere. Lichina intermedia hosted a much higher intraspecific genetic diversity than the other species, with subclades interpreted as specieslevel lineages by the different species delimitation approaches. However, a conservative taxonomic approach was adopted. This species showed a striking disjunct distribution between Australasia and southern South America. The timing for the observed interspecific and intraspecific divergences and population disjunctions postdated continental plate movements, suggesting that long-distance dispersal across body waters in the two hemispheres played a major role in shaping the current species distributions. Such ocean crossings were, as in L. canariensis, followed by speciation. New substitution rates for the nrITS of the genus Lichina were inferred using a tree spanning the major Ascomycota lineages calibrated using fossils. In conclusion, this work lays the foundation for a better understanding of the evolution through time and space of maritime lichens.

[Aim]: Lichens are often regarded as paradigms of mutualistic relationships. However, it is still poorly known how lichen-forming fungi and their photosynthetic partners in-teract at a community scale. We explored the structure of fungus-alga networks of in-teractions in lichen communities along a latitudinal transect in continental Antarctica. We expect these interactions to be highly specialized and, consequently, networks with low nestedness degree and high modularity.Location: Transantarctic Mountains from 76° S to 85° S (continental Antarctica)., [Time Period]: Present., [Major Taxa Studied]: Seventy-seven species of lichen-forming fungi and their photobionts., [Methods]: DNA barcoding of photobionts using nrITS data was conducted in 756 li-chen specimens from five regions along the Transantarctic Mountains. We built in-teraction networks for each of the five studied regions and a metaweb for the whole area. We explored the specialization of both partners using the number of partners a species interacts with and the specialization parameter d'. Network architecture parameters such as nestedness, modularity and network specialization parameter H2' were studied in all networks and contrasted through null models. Finally, we meas-ured interaction turnover along the latitudinal transect., [Results]: We recovered a total of 842 interactions. Differences in specialization be-tween partners were not statistically significant. Fungus-alga interaction networks showed high specialization and modularity, as well as low connectance and nested-ness. Despite the large turnover in interactions occurring among regions, network parameters were not correlated with latitude., [Main Conclusions]: The interaction networks established between fungi and algae in saxicolous lichen communities in continental Antarctica showed invariant properties along the latitudinal transect. Rewiring is an important driver of interaction turno-ver along the transect studied. Future work should answer whether the patterns ob-served in our study are prevalent in other regions with milder climates and in lichen communities on different substrates.

The new genus Nimisora Pérez-Ort., M. Svenss. & J. C. Zamora is introduced to accommodate a puzzling lecideoid epiphyte common in the central Iberian Peninsula. Nimisora is characterized by the following combination of characters: lecideoid apothecia, excipulum composed of sparingly branched radiating hyphae with narrow lumina, thick walls and swollen terminal cells, the presence of a brown K+ olivaceous green pigment in the epihymenium, an ascus tip similar to the Bacidia-type, and the presence of simple ellipsoid ascospores. Molecular analyses based on nrITS, nrLSU and mtSSU sequences unequivocally place the new genus within the Lecanoraceae; however, its phylogenetic affinities with other genera of the family remain largely unresolved. Comparisons with the morphologically closest genera are provided. The single species of the genus, Nimisora iberica Pérez-Ort., Turégano, M. Svenss. & J. C. Zamora sp. nov., is also described as new to science.

The Global Consortium for the Classification of Fungi and fungus-like taxa is an international initiative of more than 550 mycologists to develop an electronic structure for the classification of these organisms. The members of the Consortium originate from 55 countries/regions worldwide, from a wide range of disciplines, and include senior, mid-career and early-career mycologists and plant pathologists. The Consortium will publish a biannual update of the Outline of Fungi and fungus like taxa, to act as an international scheme for other scientists. Notes on all newly published taxa at or above the level of species will be prepared and published online on the Outline of Fungi website (https://www.outlineoffungi.org/), and these will be finally published in the biannual edition of the Outline of Fungi and fungus-like taxa. Comments on recent important taxonomic opinions on controversial topics will be included in the biannual outline. For example, ‘to promote a more stable taxonomy in Fusarium given the divergences over its generic delimitation’, or ‘are there too many genera in the Boletales?’ and even more importantly, ‘what should be done with the tremendously diverse ‘dark fungal taxa?’ There are undeniable differences in mycologists’ perceptions and opinions regarding species classification as well as the establishment of new species. Given the pluralistic nature of fungal taxonomy and its implications for species concepts and the nature of species, this consortium aims to provide a platform to better refine and stabilise fungal classification, taking into consideration views from different parties. In the future, a confidential voting system will be set up to gauge the opinions of all mycologists in the Consortium on important topics. The results of such surveys will be presented to the International Commission on the Taxonomy of Fungi (ICTF) and the Nomenclature Committee for Fungi (NCF) with opinions and percentages of votes for and against. Criticisms based

We aimed at studying the diversity of photobionts associated with lichens in a forest dominated by Quercus faginea, We aimed at studying the diversity of photobionts associated with lichens in a forest dominated by Quercus faginea

Speciation in oceanic islands has attracted the interest of scientists since the 19th century. One of the most striking evolutionary phenomena that can be studied in islands is adaptive radiation, that is, when a lineage gives rise to different species by means of ecological speciation. Some of the best-known examples of adaptive radiation are charismatic organisms like the Darwin finches of the Galapagos and the cichlid fishes of the great African lakes. In these and many other examples, a segregation of the trophic niche has been shown to be an important diversification driver. Radiations are known in other groups of organisms, such as lichen-forming fungi. However, very few studies have investigated their adaptive nature, and none have focused on the trophic niche. In this study, we explore the role of the trophic niche in a putative radiation of endemic species from the Macaronesian Region, the Ramalina decipiens group. The photobiont diversity was studied by Illumina MiSeq sequencing of the ITS2 region of 197 specimens spanning the phylogenetic breadth and geographic range of the group. A total of 66 amplicon sequence variants belonging to the four main clades of the algal genus Trebouxia were found. Approximately half of the examined thalli showed algal coexistence, but in most of them, a single main photobiont amounted to more than 90% of the reads. However, there were no significant differences in photobiont identity and in the abundance of ITS2 reads across the species of the group. We conclude that a segregation of the trophic niche has not occurred in the R. decipiens radiation.

Los procesos de biodeterioro ponen en riesgo nuestro Patrimonio Cultural y pueden llegar a suponer pérdidas de incalculable valor histórico-artístico, pero también económico. Su diagnóstico, así como el desarrollo de estrategias de tratamiento eficaces para evitar o disminuir sus efectos, sigue siendo a día de hoy un reto. Los tratamientos que se aplican en intervenciones realizadas en construcciones singulares o en obras de restauración, implican generalmente la combinación de tratamientos físicos (limpieza mecánica), junto con tratamientos químicos basados principalmente en el uso de biocidas. Sin embargo, los primeros pueden afectar a la conservación del patrimonio tratado y los segundos al medioambiente. El objetivo de este proyecto es la búsqueda de protocolos de tratamiento eficaces para evitar y frenar procesos de biodeterioro pero que, además, conlleven un mínimo riesgo patrimonial y medioambiental. Para ello, hemos puesto en marcha un experimento en las canteras de Redueña (Madrid), en el que se testan diferentes tratamientos donde se evaluará su eficacia a través de la combinación de microscopía electrónica y metabarcoding. En los ensayos se combinan: 1) pre-tratamientos con y sin limpieza mecánica con un desinfectante y 2) aplicación de distintos biocidas de nueva generación de protección en película de la Empresa Thor Especialidad S.A. La observación de las parcelas tratadas muestra que las combinaciones que implican tratamientos de limpieza mecánica son más efectivos independientemente del biocida utilizado y que el efecto de los biocidas se mantiene al menos después de un año. Esperamos que los análisis en curso nos permitan valorar los efectos específicos sobre distintos taxones y el grado de recolonización a lo largo del tiempo de ensayo.