The natural exclusion of red deer from large boulder grazing refugia and the consequences for saxicolous bryophyte and lichen ecology

Large boulder grazing refugia permitted comparison of saxicolous bryophyte and lichen assemblages with those boulder tops accessible to red deer (Cervus elaphus) on a sporting estate in northwest Scotland. Plant succession was predicted to occur unchecked by grazing on the tops of these large boulders with cascading effects on bryophytes and lichens—assuming boulders had been in place over the same time period. Fifty pairs of boulders (one ≥2 m and the other accessible to red deer) were selected at random from various locations below north-facing crags. Percentage cover of each bryophyte and lichen species was estimated from three randomly placed quadrats on each boulder top. Due consideration was given to the influence of island biogeography theory in subsequent model simplification. Mean shrub cover and height, leaf-litter, bryophyte cover and bryophyte species richness were significantly higher within quadrats on large boulder tops that naturally excluded red deer. Lichen cover and lichen species richness were significantly higher on boulder tops accessible to red deer. Lichen cover was in a significant negative relationship with bryophyte cover, shrub cover and litter cover. Bryophyte cover showed a significant positive relationship with shrub height but there was an optimum shrub cover. Natural exclusion of red deer from the tops of large boulders has facilitated plant succession. The results suggest that grazing arrests the lithosere on boulder tops accessible to red deer at an early plagioclimax favouring saxicolous lichens. The results are relevant to situations where red deer might be excluded from boulder fields that hold lichen assemblages of conservation value

Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale

While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas

Global assessment of genetic variation and phenotypic plasticity in the lichen-forming species Tephromela atra

Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology, but represents a special challenge within microbial groups. The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions. We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers. Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species, previously segregated from T. atra, agrees with molecular data. We used a genealogical concordance approach and identified 15 monophyletic clades, which may represent independent lineages. By combining morphological and chemical characters, ecological preferences and geographic origin we distinguish six different species. Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi, the continuum of variability found in morphology and chemical patterns in T. atra prevents the description of new taxa with characteristic traits. We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation. Therefore, they are insufficient for characterizing species with broad geographic ranges within T. atra

Diagnostics for a troubled backbone: testing topologicalhypotheses of trapelioid lichenized fungi in a large-scalephylogeny of Ostropomycetidae (Lecanoromycetes)

Trapelioid fungi constitute a widespread groupof mostly crust-forming lichen mycobionts that are key tounderstanding the early evolutionary splits in theOstropomycetidae, the second-most species-rich subclassof lichenized Ascomycota. The uncertain phylogeneticresolution of the approximately 170 species referred tothis group contributes to a poorly resolved backbone forthe entire subclass. Based on a data set including 657newly generated sequences from four ribosomal and fourprotein-coding gene loci, we tested a series of a priori andnew evolutionary hypotheses regarding the relationshipsof trapelioid clades within Ostropomycetidae. We foundstrong support for a monophyletic group of nine coretrapelioid genera but no statistical support to reject thelong-standing hypothesis that trapelioid genera are sisterto Baeomycetaceae or Hymeneliaceae. However, we canreject a sister group relationship to Ostropales with highconfidence. Our data also shed light on several longstandingquestions, recovering Anamylopsoraceae nestedwithin Baeomycetaceae, elucidating two major monophyleticgroups within trapelioids (recognized here asTrapeliaceae and Xylographaceae), and rejecting themonophyly of the genus Rimularia. We transfer elevenspecies of the latter genus to Lambiella and describe thegenus Parainoa to accommodate a previously misunderstoodspecies of Trapeliopsis. Past phylogenetic studies inOstropomycetidae have invoked Bdivergence order^ fordrawing taxonomic conclusions on higher level taxa.Our data show that if backbone support is lacking, contrastingsolutions may be recovered with different oradded data. We accordingly urge caution in concludingevolutionary relationships from unresolved phylogenies

Phylogenetic relationships within Pyrenodesmia

Most lichens of the family Teloschistaceae (Ascomycota) produce yellow‐orange‐red anthraquinone pigments. However, the genus Pyrenodesmia encompasses species in which anthraquinones are absent and replaced by a gray pigment Sedifolia‐gray. It was shown recently that these species are related to taxa with both anthraquinones and Sedifolia‐gray (Caloplaca xerica group, C. haematites group, and C. cretensis) and to species with a brown pigment instead of both anthraquinones and Sedifolia‐gray (C. demissa, C. obscurella, and C. reptans). Nevertheless, relationships between mentioned anthraquinone‐containing and anthraquinone‐lacking species remained unclear. In total, 8 DNA loci from 41 species were used here to resolve these uncertainties. We concluded that C. demissa, C. obscurella, and C. reptans are rather distant from the core of Pyrenodesmia, and we place them outside of Pyrenodesmia sensu lato. Within Pyrenodesmia sensu lato, three lineages were revealed and recognized on a generic level: the genus Pyrenodesmia sensu stricto (21 species), the genus Kuettlingeria (14 species), which is resurrected here, and the genus Sanguineodiscus (4 species), which is newly described here. The genus Pyrenodesmia includes taxa that never contain anthraquinones, but Sedifolia‐gray. It matches with the former C. variabilis group. Taxa of the genera Kuettlingeria and Sanguineodiscus have anthraquinones in their apothecia and Sedifolia‐gray in their thalli. The genus Kuettlingeria includes the former C. xerica group plus C. cretensis and C. diphyodes. The genus Sanguineodiscus includes the former C. haematites group and C. bicolor. The identity of Kuettlingeria (Caloplaca) diphyodes was clarified and the name Pyrenodesmia helygeoides was resurrected. Twenty‐four new combinations were proposed