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In forest ecosystems, decomposition is essential for carbon and nutrient cycling and therefore a key process for ecosystem functioning. During the decomposition process, litter chemistry, involved decomposer organisms, and enzymatic activity change interdependently. Chemical composition of the litter is the most complex and dynamic component in the decomposition process and therefore challenging to assess holistically. In this study, we aimed to characterize chemical shifts during decomposition and link them to changes in decomposer fungal activity. We characterized the chemical composition of freshly fallen autumn leaves of European beech (Fagus sylvatica) and the corresponding leaf litter after 1 year of decomposition by proton nuclear magnetic resonance spectroscopy. We further tested the applicability of spiking experiments for qualitative and quantitative characterization of leaves and litter chemistry. The composition and transcriptional activity of fungal communities was assessed by high-throughput Illumina sequencing in the same litter samples. We were able to distinguish freshly fallen leaves from 1-year-old litter based on their chemical composition. Chemical composition of leaves converged among regions with progressing decomposition. Fungal litter communities differed in composition among regions, but they were functionally redundant according to the expression of genes encoding litter degrading enzymes (CAZymes). Fungi of the saprotrophic genera Mycena and Chalara correlated with transcription of litter-degrading CAZymes in 1-year-old litter. Forestry measures influenced the diversity and transcription rate of the detected CAZymes transcripts in litter. Their expression was primarily predicted by composition of the soluble chemical fraction of the litter. Environmental NMR fingerprints thus proved valuable for inferring ecological contexts. We propose and discuss a holistic framework to link fungal activity, enzyme expression, and chemical composition.

Deadwood may alter the chemical and microbial properties of forest soils. However, it is unclear how downed deadwood (logs) of different tree species affect nutrients, microbial activity and biomass in different forest soils and regions. We investigated the effect of logs on underlying soils after 8 years of decomposition in an experiment consisting of 13 log tree species replicated at 30 forest sites across three German regions with distinct climate and geology. Soils beneath logs were compared to soils without recognizable influence of deadwood (control) 8 m away. Carbon, nitrogen, phosphorous and calcium concentrations increased by 5–18% in the soils under logs, whereas soil potassium, magnesium, iron, manganese and aluminum were not or slightly negatively affected by logs. Soils beneath logs exhibited 33%, 18% and 54% higher carbon mineralization, microbial biomass and ergosterol (component of fungal cell membranes) contents, respectively. Despite major differences in decay rates, the effect on soil properties hardly differed among the 13 log tree species. The effect of logs on microbial and chemical soil parameters increased with decreasing concentration of carbon, nitrogen, phosphorous and pH in the prevailing forest soils. Consequently, the strongest effects of logs on soil parameters occurred in plots with low soil nutrient contents and low soil pH. Our results suggest that logs of all tree species primarily increase the microbial activity and nutrient contents of acidic and nutrient-poor soils.

Climate warming is predicted to affect temperate forests severely, but the response of fine roots, key to plant nutrition, water uptake, soil carbon and nutrient cycling is unclear. Understanding how fine roots will respond to increasing temperature is a prerequisite for predicting the functioning of forests in a warmer climate. We studied the response of fine roots and their ectomycorrhizal (EcM) fungal and root-associated bacterial communities to soil warming by 4 °C in a mixed spruce-beech forest in the Austrian Limestone Alps after 8 and 14 years of soil warming, respectively. Fine root biomass and fine root production were 17% and 128% higher in the warmed plots, respectively, after 14 years. The increase in fine root biomass (13%) was not significant after 8 years of treatment, whereas specific root length, specific root area, and root tip density were significantly higher in warmed plots at both sampling occasions. Soil warming did not affect EcM exploration types and diversity, but changed their community composition, with an increase in the relative abundance of Cenococcum at 0 – 10 cm soil depth, a drought-stress tolerant genus, and an increase in short and long-distance exploration types like Sebacina and Boletus at 10 – 20 cm soil depth. Warming increased the root-associated bacterial diversity, but did not affect their community composition. Soil warming did not affect nutrient concentrations of fine roots, though we found indications of limited soil phosphorus (P) and potassium (K) availability. Our findings suggest that, in the studied ecosystem, global warming could persistently increase soil carbon inputs due to accelerated fine root growth and turnover, and could simultaneously alter fine root morphology and EcM fungal community composition towards improved nutrient foraging.

Symbiotic foliar fungal endophytes can have beneficial effects on host trees and might alleviate climate-induced stressors. Whether and how the community of foliar endophytes is dependent on the tree neighborhood is still under debate with contradicting results from different tree diversity experiments. Here, we present our finding regarding the effect of the tree neighborhood from the temperate, densely planted and 12-years-old Kreinitz tree diversity experiment. We used linear models, redundancy analysis, Procrustes analysis and Holm-corrected multiple t-tests to quantify the effects of the plot-level tree neighborhood on the diversity and composition of foliar fungal endophytes in Fagus sylvatica, Quercus petraea and Picea abies. Against our expectations, we did not find an effect of tree diversity on endophyte diversity. Endophyte composition, however, was driven by the identity of the host species. Thirteen endophytes where overabundant in tree species mixtures, which might indicate frequent spillover or positive interactions between foliar endophytes. The independence of the diversity of endophytes from the diversity of tree species might be attributed to the small plot size and the high density of tree individuals. However, the mechanistic causes for these cryptic relationships still remain to be uncovered.

Several lines of evidence suggest that the agaricoid, non-ectomycorrhizal members of the family Hygrophoraceae (waxcaps) are biotrophic with unusual nitrogen nutrition. However, methods for the axenic culture and lab-based study of these organisms remain to be developed, so our current knowledge is limited to field-based investigations. Addition of nitrogen, lime or organophosphate pesticide at an experimental field site (Sourhope) suppressed fruiting of waxcap basidiocarps. Furthermore, stable isotope natural abundance in basidiocarps were unusually high in 15 N and low in 13 C, the latter consistent with mycorrhizal nutritional status. Similar patterns were found in waxcap basidiocarps from diverse habitats across four continents. Additional data from 14 C analysis of basidiocarps and 13 C pulse label experiments suggest that these fungi are not saprotrophs but rather biotrophic endophytes and possibly mycorrhizal. The consistently high but variable δ15 N values (10-20‰) of basidiocarps further indicate that N acquisition or processing differ from other fungi; we suggest that N may be derived from acquisition of N via soil fauna high in the food chain.

Winter temperatures are projected to increase in Central Europe. Subsequently, snow cover will decrease, leading to increased soil temperature variability, with potentially different consequences for soil frost depending on e.g. altitude. Here, we experimentally evaluated the effects of increased winter soil temperature variability on the root associated mycobiome of two plant species (Calluna vulgaris and Holcus lanatus) at two sites in Germany; a colder and wetter upland site with high snow accumulation and a warmer and drier lowland site, with low snow accumulation. Mesocosm monocultures were set-up in spring 2010 at both sites (with soil and plants originating from the lowland site). In the following winter, an experimental warming pulse treatment was initiated by overhead infrared heaters and warming wires at the soil surface for half of the mesocosms at both sites. At the lowland site, the warming treatment resulted in a reduced number of days with soil frost as well as increased the average daily temperature amplitude. Contrary, the treatment caused no changes in these parameters at the upland site, which was in general a much more frost affected site. Soil and plant roots were sampled before and after the following growing season (spring and autumn 2011). High-throughput sequencing was used for profiling of the root-associated fungal (ITS marker) community (mycobiome). Site was found to have a profound effect on the composition of the mycobiome, which at the upland site was dominated by fast growing saprotrophs (Mortierellomycota), and at the lowland site by plant species-specific symbionts (e.g. Rhizoscyphus ericae and Microdochium bolleyi for C. vulgaris and H. lanatus respectively). The transplantation to the colder upland site and the temperature treatment at the warmer lowland site had comparable consequences for the mycobiome, implying that winter climate change resulting in higher temperature variability has large consequences for mycobiome structures regardless of absolute temperature of a given site.

The advantages and disadvantages of giving a valid name to a sequence of DNA detected from environmental specimens is presently a hot debate amongst the mycological community. The idea of using intracellular DNA (“mgDNA”) from environmental samples as holotypes seems at face value, to be a good idea, considering the expansion of knowledge among these ‘dark taxa’ or ‘dark matter fungi’ that it could provide (i.e. sequence based taxa without physical specimens and formal nomenclature). However, the limitations of using mgDNA as holotypes needs careful thought, i.e. can we use a short mgDNA fragment, which may contain a small amount of genetic information, to allow discrimination between species? What is the point and are the potential problems of giving valid scientific names to mgDNA? Numerous mycologists and taxonomists, who have many years of experience working on the taxonomy and phylogeny of different groups of fungi, are concerned about the consequences of providing valid names to mgDNA. There has been much debate, through several publications on the considerable problems of using mgDNA as holotypes. The proponents have tried to debate the virtues of using mgDNA as holotypes. Those against have shown that identification to species using mgDNA does not work in many fungal groups, while those for have shown cases where species can be identified with mgDNA. Different disciplines have different reasons and opinions for using mgDNA as holotypes, however even groups of the same disciplines have dissimilar ideas. In this paper we explore the use of mgDNA as holotypes. We provide evidences and opinions as to the use of mgDNA as holotypes from our own experiences. In no way do we attempt to degrade the study of DNA from environmental samples and the expansion of knowledge in to the dark taxa, but relate the issues to fungal taxonomy. In fact we show the value of using sequence data from these approaches, in dealing with the discovery of already named taxa, taxa numbers and ecological roles. We discuss the advantages and the pitfalls of using mgDNA from environmental samples as holotypes. The impacts of expanding the nomenclatural concept to allow using mgDNA from environmental samples as holotypes are also discussed. We provide evidence from case studies on Botryosphaeria, Colletotrichum, Penicillium and Xylaria. The case studies show that we cannot use mgDNA due to their short fragments and the fact that most ITS sequence data presently result from environmental sequencing. We conclude from the evidence that it is highly undesirable to use mgDNA as holotypes in naming fungal species. If this approach adopted, it would result in numerous problems where species identification cannot be confirmed due to limited sequence data available for the holotypes. We also propose an alternative DNA-based system for naming DNA based species which would provide considerably less problems and should be adopted.

Knowledge on the diversity and ecology of microfungi associated with soil-dwelling mites is rather limited. To get insights into associations between the two highly diverse groups, we studied composition and potential function of mite-associated fungal communities occurring in soil. Two different mite species living in temperate region pine forest soil were screened for associated fungi. The fungal community was assessed by restriction fragment length polymorphism (RFLP) analyses in a predatory (Leptogamasus obesus) and a predominantly saprobic (Oppiella subpectinata) mite species as well as in the organic soil layer. Key fungi were identified by sequencing, and community composition was exemplarily compared between the RFLP and a 454 metabarcoding approach. Composition of the fungal communities differed between mite species and between mites and organic soil layer. The mites were predominantly associated with Zygomycota, less frequently with Ascomycota, and rarely with Basidiomycota. The bulk soil was colonized by roughly equal proportions of the three phyla. Fungal taxa being known to exhibit chitinolytic activity were predominantly restricted to mites. Compositional and functional differences between the communities suggest that mites represent a particular microhabitat for fungi, the “acarosphere.” This mobile habitat may contribute to nutrient cycling by combining fungal and animal decomposition activities and serve as vector for soil-inhabiting fungi.

Saprotrophic and ectomycorrhizal (EcM) forest fungi decompose organic matter and mobilize nutrients for host plants, respectively. Competition between the two guilds may cause the so-called Gadgil effect, i.e., decreased litter decomposition rates resulting in increased carbon storage in soil. The Gadgil effect was supposed to even affect global climate, highlighting the necessity to understand fungal distribution and interactions in soil. Searching for evidence of competition between saprotrophic and mycorrhizal fungi, we analyzed the distribution of fungi along a well-stratified vertical spruce forest soil profile in two seasons, i.e., autumn and the following spring. The different soil strata (i.e., two mineral horizons and two organic layers) underneath the litter layer were colonized by distinct fungal communities, which included roughly consistent proportions of all fungal guilds and phyla at each time. However, the community composition changed quantitatively between the sampling dates. Along the vertical soil profile, it differed mostly between the organic layers and the mineral soil, which is supposed to be due to differences in the predominant energy sources (i.e., aboveground litter and rhizodeposition, respectively). Network analyses revealed co-occurrences (i.e., positive correlations of individual abundances) to outweigh mutual exclusions (i.e., negative correlations) between individual fungi in each soil stratum and season. This also applied for interactions between saprotrophic and EcM fungi. Network analyses therefore provided no indications for a possible Gadgil effect. However, considering individual nutrient use efficiencies might refine insights from network analyses in future studies and facilitate linking community dynamics to ecosystem processes.

Colletotrichum has a wide host range and distribution and its species are pathogens, endophytes and saprobes. Investigations of Colletotrichum species in both tropical and temperate regions are still needed as much novelty remains to be discovered. A multi-locus phylogenetic analyses of ITS, GAPDH, CHS-1, ACT and TUB2 sequence data combined with morphology, revealed a new species, C. acidae on Phyllanthus acidus, belonging to the C. truncatum species complex. A new Russian record for C. dematium on Iris sp. was also revealed. A combination of sequence data handling tools in the ARB database was used for the phylogenetic analyses and is provided in the appendix. The new species is described and illustrated in this paper and compared with taxa in the C. truncatum species complex.

Woody debris (WD) represents a litter input to forest soils, but its impact on carbon (C) cycling and the fungal community in the underlying forest floor is unclear. Here, we assessed the effect of WD of eight tree species differing in wood quality on CO2 production, microbial biomass C and fungal community of an Oe horizon from a Norway spruce forest in a combined field-laboratory study. The 78-day incubation at 20 °C comprised three treatments: Oe, WD, and Oe + WD. In the Oe treatment, the Oe horizon was previously covered with WD for 1.5 years in the Norway spruce forest. Oe horizon from control subplots that was not covered with WD in past years served as control (Oe treatment). WD originated from the 1.5-year-old field study and was either separately incubated (WD treatment) or together with Oe horizon from control subplots (Oe + WD treatment). In the Oe treatment, CO2 production and microbial biomass C were significantly higher in the Oe horizon under fast decomposing WD of Acer pseudoplatanus, Betula pendula, and Fagus sylvatica than in the Oe control. The effect of WD on the Oe horizon was even stronger in the Oe + WD treatment after separation of both substrates (day 80). CO2 production and microbial biomass C were 3–6 times or 3–5 times higher, respectively, than the control, either due to ingrowth of wood decomposing fungi or growth of autochthonous microbes in the Oe. Further, WD increased the molar C:N ratio of the Oe horizons by 1.2 units in the Oe + WD treatment. Glucose addition reduced or did not affect the CO2 production of WD, indicating that wood decomposing microorganisms were not C-limited. The fungal communities in the Oe + WD treatment were altered in both substrates, and differed primarily between angiosperm and gymnosperm WD. Fungi preferably occurring in samples with strong increase in CO2 production were native Oe fungi, indicating that invasion by wood fungi had little direct effect on C mineralization in the Oe horizon. Our results suggest that WD of common tree species represents a labile C source that can accelerate the C mineralization in the Oe horizon.

The ecological significance of fungi occurring asymptomatically inside living plant leaves is poorly understood. Given the broad saprotrophic potential of many endophytic fungi, we hypothesized that they persist in decaying litter for an extended period of time after leaf abscission. Fungal assemblages were assessed by high-throughput sequencing in autumn leaves of beech (Fagus sylvatica) and in the corresponding leaf litter in 388 samples from 22 beech forest plots in three widely distant regions of Germany. A considerable proportion of the leaf-endophytic fungi was also found in 1-year-old litter. Co-occurrence networks revealed that the fungi formed unstructured assemblages inside the living leaves, rather than well-structured communities. Previously endophytic fungi constituted an integral part of the fungal litter community and were by far the most active fungi in 1-year-old litter. We therefore consider these endophytic occurrences to represent transient stages. Composition of the aboveground microbiome appears therefore to be closely connected to the process of litter decomposition. Considering the respective linked fungal habitat will facilitate predicting nutrient and carbon cycling and storage in forest ecosystems as well as elucidating the ecology of leaf microbiomes.

The increasing number and duration of inundations is reported to be a consequence of climate change and may severely compromise non-adapted macroorganisms. The effect of flooding events on terrestrial and aquatic microbial communities is, however, less well understood. They may respond to the changed abiotic properties of their native habitat, and the native community may change due to the introduction of alien species. We designed an experiment to investigate the effect of five different flooding durations on the terrestrial and aquatic communities of eukaryotic microorganism, using the AquaFlow mesocosms. With amplicon sequencing of the small subunit (SSU) and internal transcribed spacer (ITS) rRNA gene regions, we analyzed community compositions directly before and after flooding. Subsequently, they were monitored for another 28 days, to determine the sustainability of community changes. Our results revealed a temporary increase in similarity between terrestrial and aquatic communities according to OTU composition (operational taxonomic unit, serves as a proxy for species). Increased similarity was mainly caused by the transmission of OTUs from water to soil. A minority of these were able to persist in soil until the end of the experiment. By contrast, the vast majority of soil OTUs was not transmitted to water. Flooding duration affected the community structure (abundance) more than composition (occurrence). Terrestrial communities responded immediately to flooding and the flooding duration influenced the community changes. Independent from flooding duration, all terrestrial communities recovered largely after flooding, indicating a remarkable resilience to the applied disturbances. Aquatic communities responded immediately to the applied inundations too. At the end of the experiment, they grouped according to the applied flooding duration and the amount of ammonium and chloride that leached from the soil. This indicates a sustained long-term response of the aquatic communities to flooding events.

A fungal genotype related to Mortierella alliacea was detected by environmental PCR in samples of the mite species Leptogamasus obesus and Oppiella subpectinata, as well as in the soil body. The association may be epi- or endozoic. A genotypically corresponding strain was newly isolated from mites and examined to gain deeper insight into the biology of the scarcely known fungal species. Morphological and physiological traits, as well as molecular data confirmed an affiliation to Mortierella alliacea Linnemann. However, the strain showed minor morphological differences to the original description of M. alliacea (selected here as lectotype) and to the isolate CBS 894.68 (selected here as epitype) with regard to sporocystospore and chlamydospore morphology. Therefore, an emended species description is provided. The psychrotolerant fungus is able to grow at temperatures between 0 and 25 °C. Chitin degradation was not observed, and it lacked the capability to degrade starch, cellulose, lignin, and lipids. Proteolytic activity was only exhibited at 4 °C. Co-incubated mites were not affected by the fungus, indicating that the mites predominantly serve as vectors. The fungus’ limited degradation capabilities suggest that it predominantly lives on readily accessible carbohydrates in soil.

Forest litter harbors complex networks of microorganisms whose major components are bacteria, fungi and protists. Protists, being highly selective consumers of bacteria and fungi could influence decomposition processes by shifting competitive microbial interactions. We investigated the eukaryotic diversity from 18 samples of one-year beech (Fagus sylvatica) leaf litter by RNA-based high-throughput sequencing of the small-subunit ribosomal RNA gene. By applying a metatranscriptomics approach, we avoided biases inherent to PCR-based methods, and could therefore focus on elusive protistan groups. We obtained 14 589 eukaryotic assembled sequences (contigs) representing 2223 unique taxa. Fungi dominated the eukaryotic assemblage, followed by an equal proportion of protists and plants. Among protists, the phylum Amoebozoa clearly dominated, representing more than twice the proportion of Alveolata (mostly ciliates) and Rhizaria (mostly Cercozoa), which are often retrieved as the dominant protistan groups in soils, revealing potential primer biases. By assigning functional traits to protists, we could assess that the proportion of free-living and heterotrophs was much higher than that of parasites and autotrophs, opening the way to a better understanding of the role played by the protistan communities and how biodiversity interacts with decomposition processes.

LIAS gtm, a new platform of the LIAS lichen information system, is presented. It allows for the visualization of phenotypic traits via geographic heatmapping of relative trait frequencies (RTFs) based on data derived from GBIF (occurrence data) and from LIAS light (taxon description data). The data are combined and referred to defined geographic areas of interest. Exemplarily, LIAS gtm provides distribution patterns of a selection of single, dual or multiple traits. The data are visualized for two lichen record hotspots, Scandinavia and Australia. Detailed technical information is provided on the platform web site itself.

Recent studies have indicated that arbuscular mycorrhizal fungi (AMF) are able to influence litter decomposition by interacting with the soil fungal community. However, it remains unclear exactly which constituent groups of the soil fungal community respond to AMF during litter decomposition, and in what ways. To better understand this relationship, we investigated the effect of AMF on soil fungal communities in a greenhouse experiment. Our study found that the composition and richness of the fungal community, at higher taxonomical levels (e.g. phyla, order), remained stable across treatments. However, the relative abundance of some key genera including Mycena, Glomerella, Pholiotina, and Sistotrema were significantly affected by AMF inoculation. Soil fungal community structure was also altered by AMF inoculation during the later stages of litter decomposition. Our study provides new insights into understanding the interaction between AMF and soil fungal communities and reinforces the importance of AMF in soil nutrient cycling.

A multigene phylogeny was constructed, including a significant number of representative species of the main lineages in the Xylariaceae and four DNA loci the internal transcribed spacer region (ITS), the large subunit (LSU) of the nuclear rDNA, the second largest subunit of the RNA polymerase II (RPB2), and beta-tubulin (TUB2). Specimens were selected based on more than a decade of intensive morphological and chemotaxonomic work, and cautious taxon sampling was performed to cover the major lineages of the Xylariaceae; however, with emphasis on hypoxyloid species. The comprehensive phylogenetic analysis revealed a clear-cut segregation of the Xylariaceae into several major clades, which was well in accordance with previously established morphological and chemotaxonomic concepts. One of these clades contained Annulohypoxylon, Hypoxylon, Daldinia, and other related genera that have stromatal pigments and a nodulisporium-like anamorph. They are accommodated in the family Hypoxylaceae, which is resurrected and emended. Representatives of genera with a nodulisporium-like anamorph and bipartite stromata, lacking stromatal pigments (i.e. Biscogniauxia, Camillea, and Obolarina) appeared in a clade basal to the xylarioid taxa. As they clustered with Graphostroma platystomum, they are accommodated in the Graphostromataceae. The new genus Jackrogersella with J. multiformis as type species is segregated from Annulohypoxylon. The genus Pyrenopolyporus is resurrected for Hypoxylon polyporus and allied species. The genus Daldinia and its allies Entonaema, Rhopalostroma, Ruwenzoria, and Thamnomyces appeared in two separate subclades, which may warrant further splitting of Daldinia in the future, and even Hypoxylon was divided in several clades. However, more species of these genera need to be studied before a conclusive taxonomic rearrangement can be envisaged. Epitypes were designated for several important species in which living cultures and molecular data are available, in order to stabilise the taxonomy of the Xylariales. Fil: Wendt, Lucile. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemania Fil: Sir, Esteban Benjamin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Unidad Ejecutora Lillo. Fundación Miguel Lillo. Unidad Ejecutora Lillo; Argentina Fil: Kuhnert, Eric. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemania Fil: Heitkämper, Simone. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemania Fil: Lambert, Christopher. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemania Fil: Hladki, Adriana I.. Fundación Miguel Lillo. Dirección de Botánica. Instituto de Micologia; Argentina Fil: Romero, Andrea Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Luangsa-Ard, Janet Jennifer. National Center for Genetic Engineering and Biotechnology; Tailandia Fil: Srikitikulchai, Prasert. National Center for Genetic Engineering and Biotechnology; Tailandia Fil: Peršoh, Derek. Ruhr-Universität Bochum; Alemania Fil: Stadler, Marc. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemania

Stream ecosystems are affected by multiple anthropogenic stressors worldwide. Even though effects of many single stressors are comparatively well studied, the effects of multiple stressors are difficult to predict. In particular bacteria and protists, which are responsible for the majority of ecosystem respiration and element flows, are infrequently studied with respect to multiple stressors responses. We conducted a stream mesocosm experiment to characterize the responses of single and multiple stressors on microbiota. Two functionally important stream habitats, leaf litter and benthic phototrophic rock biofilms, were exposed to three stressors in a full factorial design: fine sediment deposition, increased chloride concentration (salinization) and reduced flow velocity. We analyzed the microbial composition in the two habitat types of the mesocosms using an amplicon sequencing approach. Community analysis on different taxonomic levels as well as principle component analyses (PCoAs) based on realtive abundances of operational taxonomic units (OTUs) showed treatment specific shifts in the eukaryotic biofilm community. Analysis of variance (ANOVA) revealed that Bacillariophyta responded positively salinity and sediment increase, while the relative read abundance of chlorophyte taxa decreased. The combined effects of multiple stressors were mainly antagonistic. Therefore, the community composition in multiply stressed environments resembled the composition of the unstressed control community in terms of OTU occurrence and relative abundances.

The order Meliolales comprises the families Armatellaceae and Meliolaceae. These are black mildews that grow on the surface of host plants, often regarded as minor plant pathogens. In this study, types or specimens of 17 genera of Armatellaceae and Meliolaceae were borrowed from herbaria and re-examined. Armatella is accepted in Armatellaceae and Amazonia, Appendiculella, Asteridiella, Cryptomeliola, Endomeliola, Irenopsis and Meliola are accepted in the family Meliolaceae. Laeviomeliola is synonymized under Meliola. Ceratospermopsis, Ectendomeliola, Haraea, Hypasteridium, Leptascospora, Metasteridium, Ophiociliomyces, Ophioirenina, Ophiomeliola, Parasteridium, Pauahia, Pleomeliola, Pleomerium, Prataprajella, Ticomyces, Urupe and Xenostigme are excluded from Meliolaceae, and are treated as doubtful genera or placed in ascomycetes genera incertae sedis. The type species of each genus is re-described and illustrated with photomicrographs. Notes are provided and comparisons made. Two new species of Meliola and one new species of Irenopsis are also introduced with molecular data and we provide the most populated phylogenetic tree of Meliolomycetidae to date. Meliola thailandicum was found on Dimocarpus longan (Sapindales) and Acacia auriculiformis (Fabales) and confirmed to be the same species in the molecular analyses. This has important implications as the several hundred Meliola species are recognized based on host associations. Thus the same species being recorded from two unrelated hosts sheds doubt on Meliola species being host-specific.

Approaches for the cultivation-independent analysis of microbial communities are summarized as meta’omics, which predominantly includes metagenomic, -transcriptomic, -proteomic and -metabolomic studies. These have shown that endophytic, root-associated and soil fungal communities are strongly shaped by associated plant species. The impact of plant identity on the composition of its litter-associated fungal community remains to be disentangled from the impact of litter chemistry. The composition of the plant community also shapes the fungal community. Most strikingly, adjacent plant species may share mycorrhizal symbionts even if the plants usually have different types of mycorrhizal fungi associated with them (ectomycorrhizal, ericoid and arbuscular mycorrhizal fungi). Environmental parameters weakly explain fungal community composition globally, and their effect is inconsistent at local and regional scales. Decrease in similarity among communities with increasing distance (i.e. distance decay) has been reported from local to global scales. This pattern is only exceptionally caused by spatial dispersal limitation of fungal propagules, but mostly due to the inability of the fungi to establish at the particular locality (i.e. environmental filtering or competitive exclusion). Fungal communities usually undergo pronounced seasonal changes and also differ between consecutive years. This indicates that development of the communities is usually not solely cyclic. Meta’omic studies challenge the classical view of plant litter decomposition. They show that mycorrhizal and (previously) endophytic fungi may be involved in plant litter decomposition and only partly support the idea of a succession from an Ascomycota to a Basidiomycota-dominated community. Furthermore, vertical separation of saprotrophic and mycorrhizal species in soil and sequential degradation from easily accessible to ‘recalcitrant’ plant compounds, such as lignin, can probably not be generalized. The current models of litter decomposition may therefore have to be eventually refined for certain ecosystems and environmental conditions. To gain deeper insights into fungal ecology, a meta’omic study design is outlined which focuses on environmental processes, because fungal communities are usually taxonomically diverse, but functionally redundant. This approach would initially identify dynamics of chemical shifts in the host and/or substrate by metametabolomics. Detected shifts would be subsequently linked to microbial activity by correlation with metatranscriptomic and/or metaproteomic data. A holistic trait-based approach might finally identify factors shaping taxonomic composition in communities against the dynamics of the environmental process(es) they are involved in.

Multiple anthropogenic stressors have been shown to impact animal and plant communities in freshwater ecosystems, but the responses of aquatic fungi remain largely unknown. Stressor effects on fungal communities may, however, result in changes of decomposition of plant litter and, thus, impact nutrient cycling, a key process for ecosystem functioning. We tested the impact of increased chloride and sediment levels, as well as reduced water flow velocity, on eukaryotic freshwater communities, with an emphasis on fungi, in a mesocosm experiment. Each of the three stressors was applied individually and in all combinations in a full-factorial design. Litterbags with non-sterilised tree leaves and sterile ceramic tiles were added to the mesocosms, to analyse the responses of communities in decaying plant material and in biofilms. Fungi preferably occurring in biofilms were supposed to represent indigenous aquatic fungi, while litterbag communities should be predominantly composed of fungi known from terrestrial litter. Community composition was assessed by high-throughput sequencing of amplified barcoding regions. Similarity matrices of operational taxonomic unit (OTU) tables calculated by UCLUST and CD-HIT-OTU-Illumina were significantly correlated. Preferred occurrence in biofilm and litter communities, respectively, was used for the grouping of OTUs into three ecological guilds. Stressor sensitivity varied among the guilds. While non-fungal, in particular autotrophic, OTUs responded to several treatments, two of the fungal guilds, i.e. those exclusively colonising litter and those preferably occurring on the ceramic tiles, showed no response to any applied treatment. Only fungi preferably, but not exclusively, colonising litter significantly responded to chloride addition. Their distribution patterns again correlated significantly with those of non-fungal OTUs, indicating possible interdependencies between both groups. The results indicate that eukaryotic freshwater communities are composed of different guilds, with distinctive sensitivity and tolerance to anthropogenic stressors.

Salt mines represent an extreme environment with hypersaline conditions, complete darkness, and low nutrient availability. The diversity of filamentous fungi in such habitats is largely unknown. Eight strains of an unknown fungus were isolated from water samples of the salt mine in Berchtesgaden (Bavaria, Germany). They could be assigned to the ascomycete genus Phialosimplex, based on their common characteristics of producing conidia in chains or in heads on single phialides. Species of this genus are hitherto known to cause mycoses in dogs and have been found in mummies. Using molecular and morphological methods, the isolates are established as a new species, Phialosimplex salinarum sp. nov. Basipetospora halophila is also transferred to Phialosimplex as P. halophila comb. nov.

Sooty moulds are a remarkable, but poorly understood group of fungi. They coat fruits and leaves superficially with black mycelia, which reduces photosynthesis rates of host plants. Few researchers have, however, tried to quantify their economic importance. Sooty moulds have been well-studied at the morphological level, but they are poorly represented in a natural classification based on phylogeny. Representatives are presently known in Antennulariellaceae, Capnodiaceae, Chaetothyriaceae, Coccodiniaceae, Euantennariaceae, Metacapnodiaceae and Trichomeriaceae and several miscellaneous genera. However, molecular data is available for only five families. Most sooty mould colonies comprise numerous species and thus it is hard to confirm relationships between genera or sexual and asexual states. Future studies need to obtain single spore isolates of species to test their phylogenetic affinities and linkages between morphs. Next generation sequencing has shown sooty mould colonies to contain many more fungal species than expected, but it is not clear which species are dominant or active in the communities. They are more common in tropical, subtropical and warm temperate regions and thus their prevalence in temperate regions is likely to increase with global warming. Sooty moulds are rarely parasitized by fungicolous taxa and these may have biocontrol potential. They apparently grow in extreme environments and may be xerophilic. This needs testing as xerophilic taxa may be of interest for industrial applications. Sooty moulds grow on sugars and appear to out-compete typical “weed” fungi and bacteria. They may produce antibiotics for this purpose and their biochemical potential for obtaining novel bioactive compounds for medical application is underexplored.

For a monograph based on a polythetic concept, several thousands of herbarium specimens, and several hundreds of freshly collected and cultured specimens of Daldinia and allied Xylariaceae, originating from around the world, were studied for morphological traits, including by SEM, and chemically by HPLC profiles using UV-visible and mass spectrometric detection. Emphasis was given to tropical material, and importantly, ancient specimens, including as many types as possible, were tracked and studied to review earlier taxonomic concepts. An epitype of D. eschscholtzii was selected as representative of the morphochemotype that is most widely distributed in the tropics. Six new species of Daldinia from the tropics and the southern Hemisphere are described. Daldinia asphalatum is resurrected, and D. cudonia is regarded as its synonym. In addition, the following binomials are epi-, iso-, neo- and/or lectotypified: Daldinia asphalatum, D. caldariorum, D. clavata, D. cuprea, D. durissima, D. eschscholtzii, D. grandis, D. loculata, and D. vernicosa. Annellosporium and Versiomyces are regarded as synonyms of Daldinia. Many new synonymies in Daldinia are proposed, and some previously published names are rejected. In total, 47 taxa in Daldinia are recognised and a key is provided. Their biogeography, chorology, and ecology, as well as the importance of their secondary metabolites, are also discussed. The previous definition of the genus is emended. The species concept is based mainly on morphological and other phenotype-derived characters because, despite diligent search, no molecular data or cultures of several of the accepted species could be obtained. Daldinia is segregated into five major groups, based on phenotypic characteristics. Some unnamed but aberrant specimens were not found in good condition and are therefore not formally described as new species. However, they are illustrated in detail in a hope that this will facilitate the discovery of fresh material in future. A preliminary molecular phylogeny based on 5.8S/ITS nrDNA including numerous representatives of all hitherto described taxa for which cultures are extant, was found basically in agreement with the above mentioned segregation of the genus, based on morphological and chemotaxonomic evidence. In the rDNA based phylogenetic tree, Daldinia appears clearly distinct from members of the genera Annulohypoxylon and Hypoxylon; nevertheless, representatives of small genera of predominantly tropical origin (Entonaema, Phylacia, Ruwenzoria, Rhopalostroma, Thamnomyces) appear to have evolved from daldinioid ancestors and are nested inside the Daldinia clade. Interestingly, these findings correlate with chemotaxonomic characters to a great extent, especially regarding the distribution of marker metabolites in their mycelial cultures. Hence, the current study revealed for the first time that fungal secondary metabolite profiles can have taxonomic value beyond the species rank and even coincide with phylogenetic data.Taxonomic novelties: Daldinia andina sp. nov., D. australis sp. nov., D. hausknechtii sp. nov., D. rehmii sp. nov., D. starbaeckii sp. nov., D. theissenii sp. nov., D. cahuchosa comb. nov., D. nemorosa comb. nov.

Three new species of Hypoxylon (Xylariaceae) collected from Martinique in the French Caribbean are recognised by new combinations of morphological characters. Their status as undescribed taxa was supported by secondary metabolite profiling based on High performance liquid chromatography with diode array and mass spectrometric detection (HPLC/DAD-MS) as well as by comparison of ITS and partial s-tubulin DNA sequences with related taxa. In the course of this study, the teleomorph of Nodulisporium griseobrunneum was found, and this species could be transferred to Hypoxylon. Moreover, several names in Hypoxylon are epitypified by selecting recently collected specimens from the same geographic areas as the holotypes came from. Despite the fact that our study used the hitherto most extensive taxon sampling, the phylogenetic analyses inferred from ITS and s-tubulin sequences remain contradictory to each other, and neither genealogy was found fully in agreement with phenotype-derived traits. We conclude that the right gene (or multi-gene genealogies) to reflect the phylogeny and evolution of Hypoxylon still remains to be found. For the time being, we recommend that the application of polyphasic taxonomic concepts should be continued in taxonomic studies of Hypoxylon.

Species of Hygrocybe (waxcaps) are mostly colorful mushrooms, which are characteristic of undisturbed grasslands. These fungi are endangered in many places worldwide, but their biology remains a mystery: while isotopic signatures indicate that waxcaps are neither mycorrhizal nor saprotrophic, they were recently observed in plant roots and molecularly detected in aboveground tissues. We aimed to establish a model system of Plantago lanceolata plants colonized by H. coccinea for future detailed studies of the plant–fungus association, and species-specific primers were designed to control infection success and screen environmental samples for waxcaps. The experimentally treated plants grown from surface-sterilized seeds were indeed colonized by waxcaps after 22 weeks of incubation. However, the fungal infection was independent from the experimental treatment and apparently resulted from infected seeds. Screening of field material confirmed that at least one species, i.e., H. virginea, is a maternally transmitted endophytic fungus associated with P. lanceolata. In the experiments, it obviously expanded to the roots during or after seed germination. The endophytic growth is also consistent with the carbon isotopic signature of Hygrocybe, which deviates less from the host plants’ signature than known from ectomycorrhizal associations. However, waxcaps obviously acquire nitrogen (N) from a source outside the plant, like mycorrhizal fungi do. The extensive root system of P. lanceolata is hypothesized to facilitate reaching of nitrogen sources for Hygrocybe which are enriched in the heavier 15 N isotope.

Endophytic fungal communities have been shown to be highly diverse in almost every host plant species analyzed so far. However, the factors shaping their compositions are largely unknown. To elucidate the impact of various factors, 10 independent replicates of DNA extracts from each of 17 surface-sterilized leaf and stem samples were analyzed by pyrosequencing of fungal ITS1 rRNA gene amplicons. Altogether, 154 fungal OTUs (operational taxonomic units), represented by 953,385 sequences, were found in at least 2 samples from Viscum album ssp. austriacum and/or its host Pinus sylvestris. Deviating from earlier, cultivation-based assessments, the communities were dominated by OTUs related to the genus Mortierella and OTUs not assignable to a certain fungal phylum. However, Ascomycota were still the most diverse group in terms of OTU richness and already hypothesized organ and host preferences of certain endophytic Xylariaceae isolated from the Pinus-Viscum-system could be confirmed. Host species and organ type were also the major factors shaping the detected fungal communities. The two plant species clearly differed according to the endophytic fungal communities, but only stems and needles of Pinus were inhabited by significantly different fungal assemblages. Interestingly, only the 1 and 3 year old stem sections differed according to the endophytic fungal community, while differently aged leaves of both plants were indistinguishable in this regard. Size of the organs had no impact on fungal communities in Pinus, but shorter internodes and smaller leaves showed at least a tendency to differ from the corresponding larger organs in Viscum. Fungal communities also differed slightly between the two sampling sites, lying 200 km apart, and between the three sampling campaigns. Because the samples were drawn within 15 days, this finding indicates that seasonal shifts clearly outweigh aging effects in host plant with perennial leaves. The results therefore provide strong evidence against a linear development of the endophytic fungal communities in Pinus sylvestris and Viscum album over the years. The communities seem to establish themselves already in the year the respective organs emerge. Further study is required to clarify whether they predominantly establish anew each year, or if the core community persists throughout subsequent years. The most abundant endophytic OTUs are known from soil and/or dead plant material and are supposed to represent latent decomposers. The study reveals for the first time that host and/or organ preferences of putatively saprotrophic fungi are predominantly responsible for compositional differences in the endophytic fungal communities between host plants and organs. While the analyses are shown to provide rather robust results, the significance of genetic abundance, as revealed by high-throughput sequencing analyses, remains an unsettled issue. This is discussed in detail, as well as the challenges in assigning taxonomic names to OTUs.

Many microfungi are able to live in living plant tissues. In contrast to plant pathogens and parasites the so-called endophytic fungi do not cause obvious disease symptoms in their hosts. Nevertheless, they constitute an ubiquitous active component in direct and multitrophic interactions. The present study was conducted to assess the level of overlap of cultivable microfungi in living and decaying tissues of European Beech (Fagus sylvatica L.) from a forest stand in North-Eastern Germany. The focus lay on the hypothesized fall-spring relationship of leaf-inhabiting forest endophytes, which means that endophytes from autumn leaves persist as saprobes in litter or dead wood, sporulate and re-invade living leaves in spring. Fungal cultures were isolated from living leaves, leaf litter and dead wood still attached to the tree by dilution-to-extinction cultivation in the years 2007–2010. Analyses of species identity, species richness and species composition were based on microscopic identification and of sequencing the fungal DNA ‘barcode’ ITS (internal transcribed spacer). Species richness of litter-inhabiting microfungi equaled that of wood-inhabiting fungi and exceeded that of leaf endophytes. The most distinctive species assemblage was observed on wood, fungal species composition in living leaves and leaf litter were also significantly different from each other. On the other hand a considerable compositional and phylogenetic overlap between leaf and litter fungi was revealed with phylogenetics, cluster analysis and non-metric multidimensional scaling. The taxa accounting most to the similarity between living and decaying leaves belonged to Capnodiales, Xylariales, Diaporthales and Pleosporales. Finally, data from cultivated leaf-inhabiting beech endophytes were compared with a fungal 454 sequence data set from beech phyllosphere. This analysis allowed the partition of species lists into active fungal endophytes, fungal “epiphytes” and dormant fungal propagules.

Biodiversity research rapidly progresses due to the continuous improvement of high-throughput analysis platforms, which facilitate detailed analyses of the composition and architecture of microbial communities in various environmental niches. In the fields of applied forestry and agriculture, microbial communities are also increasingly considered, because they are involved in various kinds of biotic interactions with plants and therefore have high diagnostic value for assessing the health status of plants and soils. While in-depth identification of microbial species in environmental samples is currently achieved by next generation sequencing or microarray techniques, profiling of whole microbial communities can be accomplished via less labor-intensive approaches. We modified the protocol for automated ribosomal intergenic spacer analysis (ARISA) by targeting length polymorphism of the fungal ITS1 rRNA gene for a rapid diagnostic assessment of fungal community composition and surveyed its application spectrum. The approach allowed for spatial and temporal differentiation among fungal assemblages in soil samples and different plant species, and is therefore particularly useful for environmental screening and monitoring projects. Standardized experimental conditions permit the cumulative gathering of data, for instance during long-term projects.

Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology.

The fungal communities in living and decomposed leaves of European Beech (Fagus sylvatica) were compared to identify the phyllosphere fungi involved in litter decomposition at a site in Bavaria, Germany. New primers were designed to cover a broad range of fungal ribosomal DNA sequence diversity. Following ‘environmental PCR’, clone libraries from each of five samples of living leaves (surface-sterilized and untreated), freshly fallen, initially and highly decomposed leaves, were screened using RFLP fingerprinting. Statistical analysis (ANOSIM) revealed that the fungal communities colonizing living (a) and initially decomposed leaves (c) significantly differed between each other and from freshly fallen (b) and highly decomposed leaves (d). Fungal assemblages of a and d were statistically indistinguishable from each other and from the endophyllous fungal community in living leaves. The results showed that endophyllous fungi play a role throughout the whole decomposition process of beech leaf litter. Therefore, clarification of the life cycle of certain endophytic and/or soil fungi may only be achieved by considering both phyllosphere and soil habitats.

In the present study, a well-defined lichen community was screened for associated fungi for the first time. The photophilous lichen community Letharietum vulpinae was chosen because its character species, Letharia vulpina, was expected to host rather specialized fungi due to the presence of antimycotic secondary compounds. A considerable number of the associated fungi that were isolated were probably selective for lichens, because they appeared to be distantly related to fungi known from other substrates. The majority of these obligatory, lichen-associated fungi were only isolated in the course of the present study and represent hitherto unknown phylogenetic lineages. Parts of the lichen-associated fungi overlapped those colonizing rock surfaces or were closely related to endophytic fungi, but the lichen-associated and endophytic fungi still represented separate lineages.

Background and aims Soil freeze-thaw cycle (FTC) regimes are altered by climate change and known to influence nutrient cycling and plant growth. Here, we explore mechanistic explanations for the changing plant performance of the grass Holcus lanatus and the dwarf shrub Calluna vulgaris.

The xylariaceous genus Rhopalostroma comprises a small conglomerate of stromatic, angiosperm-associated pyrenomycetes, which have so far exclusively been reported from the palaeotropics, above all from tropical Africa and South Asia. Morphological and chemotaxonomic studies had suggested their close relationship to the genera Daldinia and Hypoxylon. However, those results were mainly based on herbarium specimens, and no molecular phylogenetic data were available on Rhopalostroma. During a foray in Cote d'Ivoire, fresh material of R. angolense was collected, cultured and studied by microscopic methods and by secondary metabolite profiling using high performance liquid chromatography coupled with diode array and mass spectrometric detection. In addition, ITS nrDNA sequences of the cultures were generated and compared to those of representative Xylariaceae taxa, to evaluate the phylogenetic affinities of this fungus. The results showed that R. angolense is closely related to the daldinoid Xylariaceae, and in particular to the predominantly neotropical genera Phylacia and Thamnomyces.

Three undescribed European species of Xylaria are recognized from new combinations of anamorphic and teleomorphic characters. Their phylogenetic affinities are revealed by a 5.8S/ITS nrDNA analysis. Two of them (X. karsticola and X. vasconica) appear closely related to X. hypoxylon sensu stricto. Xylaria cinerea is distributed in western Europe (France, Spain, United Kingdom) and the Canary Islands and appears closely related to a yet unnamed taxon from New Zealand. In addition to southwestern Europe, X. vasconica is also present in eastern USA. A specimen of X. hypoxylon from the US West Coast agreed with European material with regard to the teleomorph, but its cultures showed a different morphology. Xylaria arbuscula var. plenofissura is reported from a natural habitat on the European mainland for the first time, and the occurrence of this member of the X. arbuscula complex on the Canary Islands is confirmed.

The tropical genus Thamnomyces is characterized by having wiry, black, brittle stromata and early deliquescent asci, lacking an amyloid apical apparatus. Thamnomyces is regarded as a member of the Xylariaceae because the morphology of its ascospores and the anamorphic structures are typical for this family. However, its relationship to other xylariaceous genera remained to be clarified. Cultures of three Thamnomyces species were obtained and studied for morphological characters, and their secondary metabolite profiles as inferred from high performance liquid chromatography coupled with mass spectrometric and diode array detection (HPLC–MS/DAD) were also compared. Cultures of Thamnomyces closely resembled those of the genera Daldinia and Phylacia and even produced several secondary metabolite families that are known to be chemotaxonomic markers for the aforementioned genera. These findings were corroborated by a comparison of their 5.8S/ITS nrDNA sequences. We conclude that Thamnomyces, Daldinia, and Phylacia are derived from the same evolutionary lineage, despite these genera differing drastically in their stromatal morphology and anatomy. Along with Entonaema and Rhopalostoma, these fungi comprise an evolutionarily derived lineage of the hypoxyloid Xylariaceae. A new species of Thamnomyces is erected, and preliminary descriptions of three further, potentially new taxa are also provided.

Morphological and anatomical characters of four ectomycorrhizae with affinities to the genera Humaria, Geopora, and Trichophaea of Pyronemataceae (Pezizomycetes, Ascomycota) on Chinese Pine (Pinus tabulaeformis) are described. The ectomycorrhizae are yellowish brown to brown, and have pseudoparenchymatous outer mantle layers and partially warty emanating hyphae with thick walls and without clamps. Intrahyphal hyphae are present, and no rhizomorphs are formed. The four ectomycorrhizae are distinguishable by differences in cell shape of outer mantle layers and the presence of cystidia. Ectomycorrhizae of a possible Humaria species (Pinirhiza humarioides) lack cystidia and have irregularly inflated cells on the outer mantle layer that are connected with thin septa. The two ectomycorrhizae showing probable affinities to Geopora species (“P. daqingensis” and “P. geoporoides”) possess row-like arranged cells in the outer mantle layer and cell heaps, and differ by the presence or absence of cystidia as well as by the structure of the inner mantle layers. Ectomycorrhizae likely having been formed by a Trichophaea species (“P. trichophaeoides”) have oval to polygonal cells and no cystidia. The possible taxa affiliations were assessed by molecular-phylogenetic analyses of the internal transcribed spacer (ITS) and partial large subunit (LSU) nrDNA. Morphological and anatomical characters are discussed against the background of the LSU phylogeny.

Detailed morphological investigations and phylogenetic analyses of the ITS/5.8S nrDNA reveal Umbilicaria caroliniana to be a member of Lasallia. A new combination, Lasallia caroliniana (Tuck.) Davydov, Persoh & Rambold comb. nov., is proposed. The circumscription of Lasallia is extended by the character state of eight-spored asci. According to the new concept, Lasallia is distinguished from Umbilicaria by comprising species which combine large, multicellular, brown ascospores and a pustulate thallus. The functionally significant differences in ascospore morphology justify the current division of Umbilicariaceae into Lasallia and Umbilicaria, although Umbilicaria remains paraphyletic.