We studied the effects of different mat-forming lichens on microclimate and litter decomposition in an alpine ecosystem where lichens constitute a major part of the vegetation. We used four lichens with contrasting colour and water-holding capacity. We recorded soil temperature and moisture, and decomposition rate of plant litter under the different lichen mats and in bare soil. While soil temperature and freeze-thaw cycles were reduced under all lichen mats compared to bare soil, Cladonia rangiferina/Cladonia stygia insulated stronger than other lichens. Litter decomposition was faster under Flavocetraria nivalis than under Alectoria ochroleuca, but this was not related to lichen traits or microclimate. We conclude that insulation by lichen mats is stronger with higher water-holding capacity, and we suggest that microbial communities associated with different lichens have a larger effect on litter decomposition than soil conditions. Our findings highlight the importance of mat-forming lichens on microclimate and ecosystem processes in alpine environments.

The effects of irrigation on colonization of Pinus sylvestris and Quercus pubescens by members of the Phialocephala fortinii s.l. – Acephala applanata species complex (PAC) was assessed. Roots were collected from an irrigation experiment site. PAC species were identified based on 13 microsatellites. Irrigation and host species had a significant effect on the frequency of roots colonized by PAC. In oak (Q. pubescens) but not in pine (P. sylvestris), PAC were significantly more common on dry non-irrigated plots than on irrigated ones. Frequency of colonization of pine roots was twice as high as that of oak roots, and the mean number of PAC species per tree was significantly higher for pines. A hitherto unknown PAC species was found. The community structure was random except for the most frequently isolated Phialocephala europaea and Phialocephala helvetica, which inhibited one another in pine roots. The possible effects of PAC colonization on drought resistance of oak are discussed.

High-throughput sequencing (e.g., amplicon and shotgun) has provided new insight into the diversity and distribution of fungi around the globe, but developing a framework to understand this diversity has proved challenging. Here we review key ecological strategy theories developed for macro-organisms and discuss ways that they can be applied to fungi. We suggest that while certain elements may be applied, an easy translation does not exist. Particular aspects of fungal ecology, such as body size and growth architecture, which are critical to many existing strategy schemes, as well as guild shifting, need special consideration in fungi. Moreover, data on shifts in traits across environments, important to the development of strategy schemes for macro-organisms, also does not yet exist for fungi. We end by suggesting a way forward to add data. Additional data can open the door to the development of fungi-specific strategy schemes and an associated understanding of the trait and ecological strategy dimensions employed by the world's fungi.

There is some confusion in the scientific literature concerning terms involving insect-fungus symbioses, including associations vs. interactions, mycetangia vs. mycangia, symbiote vs. symbiont, and symbiosis vs. mutualism. We present a rationale that demonstrates the difference between an association and an interaction, and why the correct term for exoskeletal cavities that harbor fungi should be mycetangia. In addition, symbiote should be used over symbiont due to its etymology. Precise, common use of terms is important in scientific communication.

Supraglacial debris of Miage Glacier (Mont Blanc, Italy) was used as an in situ model for monitoring growth and modification of the taxonomic structure of fungal populations using an in-growth mesh bag approach over three consecutive years. Sterilized debris was placed in mesh bags (MB) and buried in the debris layer. Pristine debris (D) covering the surface of the glacier was also studied for comparative purposes. Quantitative PCR revealed that after a time of between one and two years the fungal abundance in the sterilized supraglacial debris contained in MB increased to reach a level comparable with those found in D samples. Likewise, the analysis of alpha-diversity exhibited similar dynamics during the three years of study. On the contrary, beta-diversity and Linear discriminant analysis Effect Size (LEfSe), showed apparently fluctuating dynamics from the first to the third year of study and a reduction of the number of fungal taxa discriminating MB and D samples. These observations confirm the hypothesis that fungal cells deposited on MB either by the surrounding debris or continuously brought via wind or atmospheric precipitations, can be subjected to an in situ growth which leads the abundance of the fungal communities occurring in MB to levels found in pristine debris (D) but showing fluctuating taxonomic structures.

Population genetic studies play an integral role in understanding the ecology and management of fungal plant pathogens. Such studies for species of Botryosphaeriaceae are hampered by a lack of available markers. Genomic sequences are available for multiple species in this family and they provide excellent resources for the development of population genetic markers. Here we describe highly transferable microsatellite or simple sequence repeat (SSR) markers for species in Lasiodiplodia and Neofusicoccum; two important and globally distributed members of the Botryosphaeriaceae. These were developed by extracting SSR-containing sequences from available genomes. Seventy-seven markers were developed for Lasiodiplodia and 32 markers were developed for Neofusicoccum. Most of these markers were transferable between species within a genus. Twelve markers tested for fragment length polymorphism in 20 isolates of Lasiodiplodia mahajangana identified between two and nine alleles and gene diversities between 0.18 and 0.83. Eleven markers indicated between two and five alleles for 20 isolates of Neofusicoccum parvum and gene diversities between 0.26 and 0.57. The large number and high transferability of the developed markers will facilitate population studies of a wide range of Lasiodiplodia and Neofusicoccum species associated with tree diseases globally.

Spore size, colour and melanin content are hypothesised to be functional in relation to environmental stress. Here, we studied AM fungal spores in arid environments of Australia and in an experimental platform simulating altered rainfall. We used microscopy and image analysis to measure spore colour and size, and a quantitative colorimetric assay to estimate melanin content in spores. In arid sites, melanin content tended to increase with increasing aridity. We observed a large range of spore colours at all sites but found a higher proportion of both dark and light spores, and fewer intermediate colours, in drier sites. Spore abundance and size varied among sites, but neither were related to aridity. In the experimental platform established in a grassland, we found no evidence that altered rainfall influenced spore traits. This study identifies traits associated with environmental stress to inform future work into AM fungal life history and assembly processes.

The replacement of native vegetation in riparian areas by invasive species may cause homogenization, and change the quality of allochthonous material entering streams. It may also affect colonization by aquatic hyphomycetes, which are essential for leaf decomposition. We tested the effects of non-native Hovenia dulcis on aquatic hyphomycete communities in a field experiment, as well as the litter decomposition mediated by microbial decomposers. Our findings showed that: (i) the Hovenia leaves had a faster decomposition rate than a mixture of leaves from native species; (ii) fungal sporulation rates were lower on the invasive species; (iii) Hovenia reduced the beta diversity of aquatic hyphomycetes; (iv) Hovenia made a greater contribution to alpha diversity (across litter bags) than the native mix (i.e. higher species richness), but the contribution of the native mix to the community beta diversity (across streams) was high. Our results illustrated that the composition of the riparian forest had important effects on hyphomycete communities.

Lower diversity at range margins of expanding populations is thought to reduce host-symbiont specificity of obligate symbioses. Selection for relaxed symbiont recognition systems is thought to occur when most, if not all, symbionts available to a host are genetically similar. This study evaluated whether the genetic diversity of symbiont populations along a range margin (North America) were lower than those of Neotropical populations in fungus gardening ants (subtribe Attina). Using phylogenetic, population-genetic and community-ecology approaches, we tested the hypotheses that North American fungal populations are genetically less diverse than Neotropical populations and whether they exhibit evidence of recent population expansion. Results indicated that fungal diversity is somewhat greater in the Neotropics than North America; however, North American populations are very diverse because all lineages found in the Neotropics are also represented in North America. Moreover, we found evidence of recent population expansion in both the Neotropics and North America.

An old oak tree (Quercus robur), colonized by two different lineages of the Cryptococcus neoformans species complex (VNI and VNIV), was investigated to determine the distribution of cryptococcal yeasts in the different micro-habitats of the tree. The yeasts were isolated from most of the tree micro-habitats such as bark, trunk cavities, soil beneath the tree, arthropods living on the tree, and air. Sunlight exposure and low temperatures decreased in vitro growth of VNI isolates but not that of VNIV ones. Both VNI and VNIV strains isolated from the tree were able to produce basidiospores by mating assays. The investigated tree represents an environmental reservoir of C. neoformans, where it is able to survive and probably to reproduce, and from where blastospores and basidiospores, exposed to wind, water and contact with arthropods, birds, and mammals, may be dispersed in the environment as potential infectious propagules.

Leaf economic spectrum (LES) traits are considered to be the most important plant functional traits, greatly influencing element cycling and ecosystem processes. Mycorrhizal features are considered as part of the root economic spectrum constituting the whole plant economic spectrum, and thus probably linked to LES. Arbuscular mycorrhizas (AMs) are one of the most abundant symbiotic associations in nature, however, the relationship between the global LES traits and AMs remains unknown. Here, based on the global leaf traits database, 1037 plant species with ascertained mycorrhizal types are classified into arbuscular mycorrhizal (AM) and nonAM groups in order to explore the differences in LES traits between AM and nonAM plants. Results show the worldwide LES traits are greatly linked with mycorrhizal traits. For all plants, LES traits vary greatly, but AM plants display larger variations in the six LES traits than nonAM species. AM woody plants, especially trees, have shorter leaf lifespan (LL), lower leaf mass per area (LMA), and higher leaf nitrogen concentration (Nmass), photosynthetic capacity (Amass) and dark respiration rate (Rmass) than nonAM woody ones, but similar leaf phosphorus concentration (Pmass). However, the LES traits of herbaceous plants showed no significant correlation with AMs. Compared to nonAM plants, more AM plants tend to adopt a "quick investment-return" strategy. In most cases, LES traits correlate significantly, but their interrelationships vary with mycorrhizal traits. In conclusion, AM plants possess highly varied LES traits and preference for a "quick" strategy, leading them to a high responsiveness to environmental challenges.

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.

Tricholoma matsutake is a commercially important edible ectomycorrhizal mushroom. The ecology of this species has emerged from studies of the genetic background of mycelial colonies in nature. Single putative colonies sometimes comprise several genets. This complex mycelial structure should be subjected to analysis to determine its ecophysiological significance. We tested the ectomycorrhization ability of nine T. matsutake sibling spore isolates. The ectomycorrhizal colonization ratio differed significantly among isolates, and was dependent on the soil nitrogen content. Mixed inoculations of three selected isolates into soils in which single pine seedlings were grown showed that the isolates interacted in the seedling roots. Paired inoculations of isolates #52/#99 and #52/#84, and a triple inoculation of isolates #52/#84/#99 resulted in levels of ectomycorrhizal colonization that significantly exceeded the colonization levels following single isolate inoculation. We suggest that mycelial interaction between sibling isolates is a significant phenomenon that operates within individual ectomycorrhizal pine root tips.

Coprophilous fungal taxa have been detected in several genomic surveys of root samples collected from natural habitats. However, no research to date has characterized the colonization patterns or the nature of the interaction between host plants and coprophilous fungi associated with the roots. In our study, strains of coprophilous fungi isolated from the scats of a subterranean desert rodent were described with respect to their taxonomy and life cycle, both within the scat material and when associated with the roots of a host plant. We tested the hypothesis that coprophilous fungi have the capacity to complete their life cycle in two contrasting niches, behaving as radical fungal endophytes when associated with the roots. Twenty-three strains were isolated and identified by molecular and morphological traits, all belonging to the same clade within the Lasiosphaeriaceae family, order Sordariales. Seven different selected morphotypes were inoculated in the rhizosphere of a grass species and in sterile soil-scat substrates. Five of the seven morphotypes completed their life cycle, producing ascomata with fertile ascospores in both environments. All strains developed a conspicuous melanized mycelium around the roots. Using two different approaches, root dyeing and a regrowth assay from root segments, we detected the inoculated strains inside the roots, which colonized the parenchymal tissue asymptomatically. We discuss our results in the context of the occupation of the double niche and the endophytic nature of the isolated fungi.

Maritime Antarctica is one of the most stressful environments for plant life worldwide. However, two vascular plant species (Deschampsia antarctica and Colobanthus quitensis) have been able to colonize this hostile environment. Although it has been proposed that C. quitensis possesses tolerance mechanisms and adaptations allowing survival and growth under such stressful conditions, the underlying molecular/transcriptional mechanisms are currently unknown. Furthermore, the impact of global warming on the endophytic and epiphytic organisms associated with C. quitensis remains unclear. Here, a metatranscriptomic approach was used to determine the effect of an in situ simulated global warming scenario on C. quitensis plants. We found a large number of differentially expressed genes successfully annotated (2,997), suggesting that climate change modulates the metatranscriptome of C. quitensis plants and associated endophytes and epiphytes. Interestingly, 50.5% and 26.8% of up- and down-regulated genes, respectively, are from non-plant species (putative endophytic and epiphytic organisms, such as fungi). Interestingly, Gene Ontology analysis pointed out several biological processes differentially enriched in non-plant microorganisms associated with C. quitensis grown in a simulated global warming scenario. Taken together, these results suggest that climatic drivers are shaping plant-microorganism interactions, and that endophytes/epiphytes may play crucial roles in plant adaptation to extreme environmental conditions.

Trichoderma species are applied as biological control agents and biofertilizers to control plant diseases and enhance crop yields. The ability to inhibit pathogens, induce defense responses, and promote plant growth can result from the production of volatile organic compounds (VOCs). In this study, we evaluated the effects of VOCs from Trichoderma asperellum T1 on those multifaceted actions in lettuce. The VOCs released by T. asperellum T1 inhibited fungal growth of two leaf spot fungal pathogens, Corynespora cassiicola and Curvularia aeria. Lettuces responded to VOCs by increasing activities of the cell-wall degrading enzymes chitinase and β-1,3-glucanase to 1.26 U mL−1 and 4.45 U mL−1, respectively, above those in the control. Accumulation of cell-wall degrading enzymes in lettuce that had been treated with VOCs resulted in morphological changes to fungal cell-walls. Exposure to the VOCs emitted by T. asperellum T1 significantly increased numbers of leaves and roots, plant biomass and total chlorophyll content in lettuce. Furthermore, GC/MS analysis revealed that T. asperellum T1 emitted 22 volatile compounds, which are involved in antifungal activity, inducing defense responses, and promoting growth in lettuce.

Living organisms in aquatic ecosystems are almost constantly confronted by pathogens. Nevertheless, very little is known about diseases of marine diatoms, the main primary producers of the oceans. Only a few examples of marine diatoms infected by zoosporic parasites are published, yet these studies suggest that diseases may have significant impacts on the ecology of individual diatom hosts and the composition of communities at both the producer and consumer trophic levels of food webs. Here we summarize available ecological and morphological data on chytrids, aphelids, stramenopiles (including oomycetes, labyrinthuloids, and hyphochytrids), parasitic dinoflagellates, cercozoans and phytomyxids, all of which are known zoosporic parasites of marine diatoms. Difficulties in identification of host and pathogen species and possible effects of environmental parameters on the prevalence of zoosporic parasites are discussed. Based on published data, we conclude that zoosporic parasites are much more abundant in marine ecosystems than the available literature reports, and that, at present, both the diversity and the prevalence of such pathogens are underestimated.

Most fungal species from marine environments also live on land. It is not clear whether these fungi reach the sea from terrestrial sources as spores or other propagules, or if there are separate ecotypes that live and reproduce in the sea. The emergence of marine diseases has created an urgency to understand the distribution of these fungi. Aspergillus flavus is ubiquitous in both terrestrial and marine environments. This species is an opportunistic pathogen in many hosts, making it a good model to study the relationship between genetic diversity and specificity of marine fungi. In this study, an intraspecific phylogeny of A. flavus isolates based on Amplified Fragment Length Polymorphisms (AFLPs) was used to determine if terrestrial and marine isolates form discrete populations, and to determine if phylogeny predicts substratum specificity. Results suggest lack of population structure in A. flavus. All isolates may compose a single population, with no clade particular to marine environments.

Penicillium chrysogenum is a ubiquitous airborne fungus detected in every sampled region of the Earth. Owing to its role in Alexander Fleming's serendipitous discovery of Penicillin in 1928, the fungus has generated widespread scientific interest; however its natural history is not well understood. Research has demonstrated speciation within P. chrysogenum, describing the existence of four cryptic species. To discriminate the four species, we developed protocols for species-specific diagnostic PCR directly from fungal conidia. 430 Penicillium isolates were collected to apply our rapid diagnostic tool and explore the distribution of these fungi across the London Underground rail transport system revealing significant differences between Underground lines. Phylogenetic analysis of multiple type isolates confirms that the 'Fleming species' should be named Penicillium rubens and that divergence of the four 'Chrysogenum complex' fungi occurred about 0.75 million yr ago. Finally, the formal naming of two new species, Penicillium floreyi and Penicillium chainii, is performed.

We studied the effects of Fusarium oxysporum f.sp. strigae (Fos), a soil-borne biocontrol agent (BCA) against Striga hermonthica, on total fungal and arbuscular mycorrhizal fungal (AMF) taxa in rhizospheres of maize in both clayey and sandy soil. Effects of Fos-BCA 'Foxy-2' were evaluated against (1) S. hermonthica presence, and (2) organic fertilization with Tithonia diversifolia residues at 14, 28 and 42 d after 'Foxy-2' inoculation, via DNA-based quantitative PCR and TRFLP fingerprinting. In both soils, 'Foxy-2' occasionally promoted total fungal abundance, while the community composition was mainly altered by T. diversifolia and S. hermonthica. Notably, 'Foxy-2' stimulated AMF Gigaspora margarita abundance, while G. margarita was suppressed by S. hermonthica. Total fungal and AMF abundance were promoted by T. diversifolia residues. In conclusion, 'Foxy-2' resulted in no adverse effects on indigenous rhizosphere fungal communities substantiating its environmental safety as BCA against S. hermonthica.

Obligate mutualistic symbioses rely on mechanisms that secure host-symbiont commitments to maximize host benefits and prevent symbiont cheating. Previous studies showed that somatic incompatibilities correlate with neutral-marker-based genetic distances between fungal symbionts of Panamanian Acromyrmex leaf-cutting ants, but the extent to which this relationship applies more generally remained unclear. Here we showed that genetic distances accurately predicted somatic incompatibility for Acromyrmex echinatior symbionts irrespective of whether neutral microsatellites or AFLP markers were used, but that such correlations were weaker or absent in sympatric Atta colombica colonies. Further analysis showed that the symbiont clades maintained by A. echinatior and A. colombica were likely to represent separate gene pools, so that neutral markers were unlikely to be similarly correlated with incompatibility loci that have experienced different selection regimes. We suggest that evolutionarily derived claustral colony founding by Atta queens may have removed selection for strong incompatibility in Atta fungi, as this condition makes the likelihood of symbiont swaps much lower than in Acromyrmex, where incipient nests stay open because queens have to forage until the first workers emerge.

As the use of functional trait approaches is growing in fungal ecology, there is a corresponding need to understand trait variation. Much of trait theory and statistical techniques are built on the assumption that interspecific variation is larger than intraspecific variation. This allows the use of mean trait values for species, which the vast majority of trait studies adopt. We examined the size of intra- vs. inter-specific variation in two wood fungal fruit body traits: size and density. Both coefficients of variation (CV) and Trait Probability Density analyses were used to quantify trait variation. We found that intraspecific variation in fruit body density was more than twice as variable as interspecific variation, and fruit body size was hugely variable (CVs averaged 190%), although interspecific variation was larger. Further, there was a very high degree of overlap in the trait space of species, indicating that there may be little niche partitioning at the species level. These findings show that intraspecific variation is highly important and should be accounted for when using trait approaches to understand fungal ecology. More data on variation of other fungal traits is also desperately needed to ascertain whether the high level of variation found here is typical for fungi. While the need to measure individuals does reduce the ability to generalise at the species level, it does not negate the usefulness of fungal trait measurements. There are two reasons for this: first, the ecology of most fungal species remains poorly known and trait measurements address this gap; and secondly, if trait overlap between species more generally is as much as we found here, then individual measurements may be more helpful than species identity for untangling fungal community dynamics.

Pyrophilous fungi produce sporocarps after a fire but little is known about their ecology prior to or after a fire event. Recently, the body snatchers hypothesis was proposed that suggests some post-fire fungi form endophytic and/or endolichenic relationships with plants and lichens. To test the body snatchers hypothesis, bryophyte, lichen, club moss, and soil samples were collected from unburned and mixed-intensity burned areas 1–2 y after a 2016 wildfire in the Great Smoky Mountains National Park, and from unburned areas in four states outside the park. Samples were examined for the presence of pyrophilous fungi occurring as endophytes or in lichens using culture-dependent and culture-independent techniques. Culture-dependent methods isolated Pholiota highlandensis, a known pyrophilous fungus, from five bryophyte samples. Culture-independent methods identified 22 pyrophilous taxa from bryophyte, club moss, lichen, and soil samples across a range of geographical localities. The ‘body snatchers’ hypothesis is supported since many bryophyte, lichen, and club moss samples contained pyrophilous taxa suggesting that these fungi occur as endophytes and/or endolichenic fungi until a fire event triggers them to produce sporocarps.

Fungi are key organisms in terrestrial ecosystems, functioning as decomposers, pathogens, and symbionts. Identifying the mechanisms that shape metacommunity patterns is likely to be critical for predicting how ecosystems will respond to global environmental change. Using fungal occurrence data and a hierarchical approach that combines three elements of metacommunity structure—coherence, turnover and boundary clumping—we identified the structures that best describe metacommunity patterns. We related these patterns to underlying environmental and spatial variables known to influence fungal distribution, and determined the relative importance of the environment and geographic distance in structuring fungal metacommunities. Fungal metacommunities had Clementsian and quasi-Clementsian structures, indicating that species distributions were compartmentalized along a dominant environmental gradient. This gradient was strongly associated with annual precipitation, precipitation seasonality and pH for the entire metacommunity. Variance partitioning revealed that the environment was relatively more important than geographic distance in explaining metacommunity patterns, indicating that niche-based processes are crucial in shaping species distributions among sites. However, the strength of the relationship between the latent gradient and environmental factors and the relative contributions of the environment and geographic distance to metacommunity structure varied across groups, suggesting that interactions among habitat, dispersal and life-history might be driving these differences.

Taxonomy and diversity of symptomatic lichenicolous fungi (visible as fruitbodies on lichen thalli, their discoloration, and/or deformation) and their specificity to lichen hosts is becoming more and more studied. However, information on their ecology is still scarce. We assess how large the specialization of these fungi towards their hosts and microhabitat is. Epiphytic, epixylic and epigeic lichens and associated lichenicolous fungi were studied on 144 permanent plots in Białowieża Forest in relation to forest communities, species of tree phorophyte and substrates. On all these three studied levels lichenicolous fungi were more specialized than their lichen hosts. Our study provides the first estimation of ecological dependences between associations of lichenicolous fungi and their hosts, microhabitats and forest communities in a primeval forest ecosystem representative of lowland Europe.

Tree species is one of the most important determinants of wood-inhabiting fungal community composition, yet its relationship with fungal reproductive and dispersal traits remains poorly understood. We studied fungal communities (total of 657 species) inhabiting broadleaved and coniferous dead wood (total of 192 logs) in 12 semi-natural boreal forests. We utilized a trait-based hierarchical joint species distribution model to examine how the relationship between dead wood quality and species occurrence correlates with reproductive and dispersal morphological traits. Broadleaved trees had higher species richness than conifers, due to discomycetoids and pyrenomycetoids specializing in them. Resupinate and pileate species were generally specialized in coniferous dead wood. Fungi inhabiting broadleaved trees had larger and more elongated spores than fungi in conifers. Spore size was larger and spore shape more spherical in species occupying large dead wood units. These results indicate the selective effect of dead wood quality, visible not only in species diversity, but also in reproductive and dispersal traits.

Kauri dieback, caused by Phytophthora agathidicida, is an emergent threat to the ecologically unique and carbon-rich kauri (Agathis australis) forests in New Zealand. Our main aim was to assess the effect of kauri dieback on canopy and forest floor dissolved and particulate carbon (C) and nitrogen (N) fluxes. Throughfall and stemflow collectors and free-draining lysimeters were deployed underneath the canopy of ten kauri trees differing in their soil P. agathidicida DNA concentration and visual health status and sampled weekly to monthly over 1 y. Throughfall and forest floor dissolved C and N fluxes decreased significantly with increasing soil P. agathidicida DNA concentration which may be related to changes in leaf chemistry, leachable kauri leaf surface area and uptake of N by the understory vegetation. The observed alteration in dissolved and particulate C and N fluxes under P. agathidicida infected kauri trees could lead to long-term changes in biogeochemical processes (e.g. mineralization, nutrient availability) in these ecologically unique kauri forests.

Foliar endophytic fungi are present in almost all vascular plants. The composition of endophyte communities varies among plant individuals. Likely, but understudied, sources of this variation are the species composition of the plant community and initial attacks by insect herbivores. We addressed these issues by characterizing fungal endophyte communities on leaves of chestnut (Castanea sativa) grown in pure vs. mixed stands. We used ITS metabarcoding methods to identify endophytic fungi associated with galls caused by the invasive gall wasp, Dryocosmus kuriphilus, and with surrounding chestnut leaf tissues. We found 1378 different OTUs. The richness, diversity and composition of endophyte communities differed between galls and surrounding leaf tissues but were independent of forest stand composition. Fungal endophyte richness was lower in galls than in surrounding leaf tissues. Most differences in the composition of fungal endophyte communities between galls and foliar tissues were due to OTU turnover. These results suggest that insect-induced galls provide a particular habitat condition for endophytic microorganisms, regardless of forest species composition. A better understanding of endophyte biology is important to improve their use as biocontrol agents of galling insects.

Aquatic hyphomycetes (AH) are ubiquitous fungi playing a key role in the decomposition of leaf litter in streams. Though their functional performance is modulated by their community composition, this ecological relationship remains poorly investigated due to a lack of suitable methods to identify the biomass-contribution of individual species to AH communities. We, therefore, designed and validated TaqMan® probe-based qPCR assays targeting ten AH species common in temperate regions, allowing detection and quantification of these species within complex communities. In a further step, we compared qPCR-obtained DNA levels to concentrations of the traditional fungal biomass proxy ergosterol. We demonstrate that the qPCR assays are valid for use and that DNA and ergosterol concentrations were significantly positively correlated, suggesting DNA levels as a suitable species-specific biomass proxy. Accordingly, the use of these assays may facilitate multi-species experiments to address major research issues in stress and community ecology including biodiversity-ecosystem functioning relationships.

The earliest stages of bacterial colonisation of wood have received little attention, particularly with respect to how the colonisation process may be affected by the presence of wood-decay fungi. This study used 16s rRNA gene sequencing to examine the bacterial community in wood that had been incubated in the field for 14 or 84 d, either in wood uncolonised by fungi or pre-colonised by Vuilleminia comedens, Trametes versicolor or Hypholoma fasciculare. All three fungal species significantly delayed bacterial colonisation of the wood. V. comedens and H. fasciculare also reduced bacterial OTU richness and altered bacterial community composition, increasing the relative abundance of Burkholderiales and reducing the proportion of Enterobacteriaceae and Bacteroidetes. Wood that had not been pre-colonised showed seasonal differences between autumn and spring: bacterial richness increased between 14 d and 84 d in the spring, but not in the autumn. Community composition at 84 d in spring was also different to the other time points, with reduced dominance of Gamma-proteobacteria. Archaea were also detected in nearly a third of samples, but with no apparent pattern, and always at low abundances.

The cyst of the soya bean cyst nematode (SCN; Heterodera glycines), an economically important pathogen of soya beans worldwide, represents a unique microhabitat in soil. The fungi inhabiting cysts may include natural antagonists of the SCN as well as saprotrophs and other opportunists. This study aimed to characterise the entire culturable mycobiome of SCN cysts obtained from a long-term soya bean-corn rotation experiment using ITS fungal barcoding. Fusarium was consistently the most frequently isolated taxon across all sampling time points and crop sequences, followed by Ilyonectria. Among fourteen genera frequently isolated from SCN cysts, five fell within the single family Nectriaceae (Sordariomycetes) and five within the order Pleosporales (Dothideomycetes), suggesting independent evolutionary origins and shared adaptations in these groups towards colonisation of SCN cysts. Six genera (Pochonia, Clonostachys, Fusarium, Neonectria, Alternaria, and Leptosphaeria) varied significantly by crop sequence in at least one year.

Mycorrhizal interactions are critical for the orchid life cycle, and some orchid species associate with a very narrow suite of fungal partners. To investigate whether mycorrhizal specificity correlates with extent of distribution in the host plant, we studied fungal symbionts in two Caladenia species-pair contrasts, each pairing one widely distributed species with a closely-related species of narrow distribution. Across four orchid species, we identified 70 fungal isolates and 121 clone sequences of the fungal genus Serendipita. The widespread C. pectinata associated with two operational taxonomic units (OTUs) and in vitro seed successfully germinated on four OTUs. The narrowly distributed C. procera associated with two OTUs and was germinated by two OTUs. Four OTUs were identified in widespread C. tentaculata compared to one OTU in the narrow distribution C. atrovespa. The suite of OTUs observed associating with adult plants was different from those successfully germinating seed of the same species, suggesting weaker specificity during germination. We found that fungi germinating narrowly distributed orchids are themselves widespread, and are therefore unlikely to limit orchid distribution at a landscape level.

Some species of the fungal genus Ophiocordyceps that parasitize ants have evolved some degree of behavioral manipulation to increase their own transmission. Carpenter ants (Camponotus spp.) infected by Ophiocordyceps unilateralis species climb vegetation and bite leaves or other plant parts before death, while other ants infected by other Ophiocordyceps species die buried within or on the leaf-litter, attached to stems and tree trunks. The microenvironment of the host's death location is important for fungal development and dispersal to new hosts, being an interesting example of an extended phenotype. This study investigated the effect of humidity variation in space (15 km2) and time (14 months) on the occurrence and expression of the extended Ophiocordyceps phenotype parasitizing ants in Central Amazonia. We found O. unilateralis s.l., O. kniphofioides s.l. and O. australis s.l. parasitizing 30 ant species, but O. unilateralis s.l. was by far the most abundant fungus. Parasitized Camponotus atriceps and C. bispinosus were more abundant and died in higher places in periods with greater air humidity. Otherwise, the abundance and height of C. senex cadavers were higher in drier plots. These results provide insights on how the spatial and temporal variation in air humidity may shape the occurrence and behavioral manipulation of ants infected by entomopathogenic fungi at larger scales.

Ash dieback disease (caused by Hymenoscyphus fraxineus) has affected European ash species (Fraxinus spp.) in recent decades. However, some Asian and American species of Fraxinus and certain genotypes of Fraxinus excelsior are less affected by the disease. We used ITS1-metabacoding to explore the drivers influencing diversity and composition of the twig fungal communities of Fraxinus species and F. excelsior genotypes. Our results revealed that fungi in the classes Eurotiomycetes and Dothideomycetes were among the most prevalent taxa in both Fraxinus species and F. excelsior genotypes. The diversity of the fungal communities differed significantly among Fraxinus species and could be explained by seed origin. Neither host genotype nor season had a significant effect on the community diversity of F. excelsior genotypes. On the other hand, the composition of twig fungal communities differed significantly among host species and among F. excelsior genotypes, and in F. excelsior there was also a significant effect of season on the composition of the fungal community. We did not find a clear effect of ash dieback susceptibility on either diversity or composition of fungal communities in twigs of Fraxinus species, although the effect was significant on the composition of fungal communities among F. excelsior genotypes. Our results demonstrated differences in fungal communities among species of Fraxinus and of F. excelsior genotypes, suggesting specific relationship between individual host genotypes and endophytic fungi.

This study aimed to inventory fungal populations associated with the rhizosphere of Avicennia germinans in different salinity levels in a semi-arid mangrove in the Colombian tropics. Targeting the ITS1 and ITS2 regions provided complementary information, allowing a better approach to inventorying the fungal biodiversity. Amorosia and Aspergillus were the most abundant ascomycete genera, while Cystobasidium was the most abundant basidiomycete genus. Only five genera showed significant differences in abundance among the three salinity levels. Nevertheless, 65.4% of the genera were classified as exclusive for a specific salt content. Saprotrophs were the most abundant functional group and symbiotrophs were detected as mycorrhizas, fungi with biocontrol activity and entomopathogenic activity. These ecological groups play an important role in the cycling of organic matter and the availability of nutrients for mangrove plants and their tolerance to environmental and biotic stresses. This study highlights soil salinity as a determining factor in the composition of the fungal community in mangroves.

Bark and ambrosia beetles (Curculionidae: Scolytinae) are known for their symbioses with fungi and play a key role in the dispersal of phytopathogens. The scolytine community of eight pine stands along a latitudinal gradient in the UK was surveyed and beetle-associated fungal communities (mycobiota) were assessed using ITS2 metabarcoding (304 specimens, 12 species). Distribution patterns among 2,257 detected fungal Operational Taxonomic Units (OTUs) revealed that beetle species identity was an important predictor of mycobiotic richness and composition, while the effects of environmental and spatial variables were negligible. Network-based specificity analysis suggested that a relatively small subset of OTUs (75 in total) exhibit an affinity for a subset of beetle species and that these include many Microascales and Saccharomycetes. Notably though, of the OTUs belonging to the family Ophiostomataceae, relatively few display host specificity. Our results add to the complex picture of host-associated fungal communities and suggest that host range limits are unlikely to restrict the spread of economically important phytopathogens.

Fungal communities play important roles in terrestrial ecosystem functioning. Unraveling the relative importance of stochastic versus deterministic processes in shaping biogeographic patterns of fungal communities has long been a challenge in microbial ecology, owing to high biodiversity and difficulties in identifying fungal taxa. Using a unique anthropogenic system of geographically isolated paddy ‘islands’, we collected 198 soil samples with a spatially explicit design to examine how ecological processes shaped fungal biogeographic patterns. Fungal community structure showed scale-dependent distance-decay relationships. Stochastic processes (dispersal and drift) contributed more to community assembly than deterministic processes (selection) at the local scale, which was largely attributed to drift. In contrast, deterministic processes contributed more to community assembly than stochastic processes at the regional scale, with soil dissolved organic carbon being the most important measured factor. Collectively, scale dependence of fungal biogeographical patterns in paddy soils is influenced by differential contribution of deterministic and stochastic processes.

While the negative effects of infrequent, high-intensity fire on soil fungal abundance are well-understood, it remains unclear how the short-term history of frequent, low-intensity fire in fire-dependent ecosystems impacts abundance, and whether this history governs any abundance declines. We used prescribed fire to experimentally alter the short-term fire history of patches within a fire-frequented old-growth pine savanna over a 3 y period. We then quantified fungal abundance before and after the final fire using phospholipid fatty acid (PLFA) assays and Droplet Digital™ PCR (ddPCR). Short-term fire history largely did not affect total fungal abundance nor pre-to post-fire abundance shifts. While producing similar conclusions, PLFA and ddPCR data were not correlated. In addition to piloting a new method to quantify soil fungal abundance, our findings indicate that, within fire-frequented pine savannas, recurrent fires do not consistently decrease total fungal abundance, and abundance changes are not contingent upon short-term fire history. This suggests that many fungi in fire-dependent ecosystems are fire-tolerant.

There is a lack of knowledge regarding the main factors modulating fungal spore deposition in forest ecosystems. We have described the local spatio-temporal dynamics of fungal spore deposition along a single fruiting season and its relation with fruit body emergence and rainfall events. Passive spore traps were weekly sampled during autumn and analysed by metabarcoding of the ITS2 region in combination with qPCR. There were larger compositional changes of deposited spores across sampling weeks than amongst sampling plots. Spore diversity and abundance correlated with mushroom emergence and weekly rainfall. Spore compositional changes were related to rainfall, with lower spatial compositional heterogeneity across plots during weeks with higher rainfall. Soil saprotrophs, and amongst them, puffball species, showed the strongest positive correlation with rainfall across fungal guilds. We saw high fine-scale temporal changes of deposited spores, and both mushroom emergence and rainfall may be important factors driving airborne spore deposition.

Riparian forests are subjected to multiple disturbances, such as tree diseases caused by invasive pathogens, whose consequences on stream functioning are unknown. We assessed the impact of Phytophthora cinnamomi infection, and interactions with temperature, on microbial decomposition of Castanea sativa leaves. Leaves from healthy, symptomatic and highly symptomatic trees were incubated in the laboratory at 13 and 18 °C for 64 d. Infection significantly increased polyphenolic concentration and leaf toughness, reducing leaf decomposition and microbial respiration rates irrespective of temperature. Aquatic hyphomycete communities differed significantly in leaves from highly symptomatic trees. Fungal biomass was highest at 18 °C, irrespective of tree health status. None of the parameters were influenced by the tree health status × temperature interaction, suggesting that temperature rise may not synergistically increase the cross-ecosystem effects caused by P. cinnamomi in streams where litter decomposition is microbial-driven. Infection by P. cinnamomi alters the nutritional quality of leaves affecting the functioning of aquatic ecosystems.

Aquatic fungi are increasingly recognized for their contribution to carbon cycling in aquatic ecosystems, both as saprotrophs and parasites. Their quantification in mixed communities is crucial to assess their ecological significance but remains challenging. We characterized the phospholipid-derived fatty acid (PLFA) composition of fifteen aquatic fungal isolates from Chytridiomycota (chytrids) and Dikarya. Additionally, we identified PLFA patterns of chytrids infecting phytoplankton and their zoospores. PLFA composition of zoospores was highly similar among different taxa, but were distinct from their respective sporangial life-stage. Finally, we applied a fatty acid-based Bayesian mixed model (FASTAR) and tested its potential to quantify fungi in complex mixtures with bacteria and phytoplankton using PLFA profiles. While the quantification of chytrid biomass in low quantities was rather imprecise, the model predicted the contribution of filamentous fungi and other components with fair accuracy, supporting the suitability of this approach to quantify fungal biomass in aquatic environments.

The epiphytic lichen Lobaria pindarensis is a Himalayan endemic species with little information on distribution, genetic diversity and structural complexity. During an intensive survey in the Nepal Himalayas, we collected 1256 thallus fragments from 45 phorophyte species to study their distribution and population genetics along an elevational gradient. We quantified genetic diversity and population structure of each symbiont at 17 fungus specific and 9 alga specific microsatellite loci. The Bayesian clustering identified three and two distinct gene pools for mycobiont and photobiont. We found that genetic diversity, allelic richness and gene pool composition and distribution were significantly influenced by elevation. We discovered both clonally and sexually reproduced repeated genotypes of the symbionts.

Plant compartments provide unique niches that lead to specific microbial associations. The microbiota colonizing the endophytic compartment (endorhizosphere) and the rhizosphere contribute to productivity, plant growth, phytoremediation and carbon sequestration. The main objective of this study was to investigate how fungal communities are enriched in different habitats outside and inside of grapevine roots. For this purpose, the spatial dynamics of the fungal communities associated with three soil-plant compartments (bulk soil, rhizosphere and endorhizosphere) were characterized by ITS high-throughput amplicon sequencing (HTAS). Fungal communities were largely affected in their diversity and composition by soil-plant compartments, whereas the spatial variation (i.e. across five vineyards) was low. The endorhizosphere compartment differed most from the other two, suggesting that the root tissues entail a barrier for fungal colonization. The results of functional prediction via FUNGuild suggested an increase in the relative abundances of potential plant pathogens, endophytes and arbuscular mycorrhiza, and a decrease in wood, dung and undefined saprotrophs from bulk soil towards the endorhizosphere. Roots of asymptomatic vines were a microbial niche that is inhabited by soilborne fungi associated with grapevine trunk diseases, which opens up new perspectives in the study of the endophytic role of these pathogens on grapevines. Results obtained in this study provide helpful information to better know how the host shapes its microbiome and the implications for vineyard productivity and management.

Metarhizium is widely recognized as an insect pathogenic fungus but it can also form symbiotic associations with plant roots. Here we assessed root rhizoplane, as well as endophytic colonization in monocots and dicots by ten Metarhizium strains representing species with either narrow or broad insect host ranges, as well as a related endophytic and nematophagous fungus, Pochonia chlamydosporia. In addition, insect pathogenicity of these strains was evaluated against mealworm (Tenebrio molitor), wax moth (Galleria mellonella) larvae and grasshoppers (Melanoplus sanguinipes). We found that all Metarhizium strains and Pochonia colonized the rhizoplane and rhizosphere of roots with varying degrees on all plants assessed. All Metarhizium strains tested showed a preference for endophytic colonization of monocot plants (within 20 d) when compared to dicots. While generalists showed pathogenicity towards all tested insect hosts, the specialists showed pathogenicity only towards grasshoppers, whereas Pochonia was avirulent towards insects. We observed variation in ability to colonize the rhizosphere amongst Metarhizium species. However, regardless of whether the Metarhizium species was a generalist or specialist insect pathogen, all strains tested retain ancestral ability to associate with plant roots.

Fungi play an important role in organic matter turnover and ensure key ecosystem services in freshwaters. The relationships between intraspecific fungal diversity and key ecological processes remain largely unknown. We examined the effects of intraspecific diversity of Articulospora tetracladia, a cosmopolitan fungal decomposer thriving on plant detritus in streams. Alder leaves were inoculated with 1 or mixtures of 2–8 fungal strains for 35 d, and leaf litter decomposition and fungal reproduction were quantified in the presence and absence of 2 mg L−1 of cadmium (Cd), a common stressor in polluted streams. Intraspecific diversity and identity affected fungal reproduction, but not leaf decomposition. Under metal stress, leaf decomposition slightly increased with intraspecific diversity. Fungal reproduction increased with intraspecific diversity and was greater in mixed assemblages, either in the absence or presence of Cd. Effect size of intraspecific diversity was higher under Cd stress for fungal reproduction, but no differences were found for leaf mass loss, with or without metal. The impacts of intraspecific diversity loss may jeopardize fungal survival and fungal functions, namely microbial leaf decomposition and leaf litter condition for invertebrate shredders in streams, particularly under metal stress.

Picea is one of the most dominant conifer genera in the Northern Hemisphere and includes species which require coarse woody debris (CWD) as a seedbed for regeneration. To understand the future of forest distribution under global climate change, it is important to investigate regeneration mechanisms in Picea forests on the borders of its distribution. In the present study, we evaluated the biotic factors affecting the establishment of Picea jezoensis var. hondoensis seedlings on CWD in one of its southernmost populations in central Japan, where there is dieback of Picea forest. Amplicon sequencing of the fungal ITS1 region of rDNA obtained from wood samples showed that forest dieback increased the frequency of brown rot fungi in CWD. The frequency of brown-rotted wood, in which wood holocellulose is decayed, increased with dieback intensity. The domination of brown-rotted wood in dieback forests was negatively associated with bryophyte cover which was positively associated with Picea seedling density. Forest dieback itself also had other strong negative effects on bryophytes. Thus, linkages between dead wood and spruce seedlings via bryophytes had collapsed after the dieback event, which may partly be a reason that the spruce forest shifted to and is staying as open grassland.

Fungivorous millipedes (subterclass Colobognatha) likely represent some of the earliest known mycophagous terrestrial arthropods, yet their fungal associates remain elusive. Here we describe relationships between fungi and the fungivorous millipede, Brachycybe lecontii. Their fungal community is surprisingly diverse, including 176 genera, 39 orders, four phyla, and several undescribed species. Of particular interest are twelve genera conserved across wood substrates and millipede clades that comprise the core fungal community of B. lecontii. Wood decay fungi, long speculated to serve as the primary food source for Brachycybe species, were absent from this core assemblage and proved lethal to millipedes in pathogenicity assays while entomopathogenic Hypocreales were more common in the core but had little effect on millipede health. This study represents the first survey of fungal communities associated with any colobognath millipede, and these results offer a glimpse into the complexity of millipede fungal communities.

Fungi play a crucial role in terrestrial Arctic ecosystems as symbionts of vascular plants and nutrient recyclers in soil, with many species persistently or temporarily inhabiting the phyllosphere of the vegetation. In this study we apply high-throughput sequencing to investigate the mycobiome of 172 samples of fresh (current year) and aged (3 year old) needles of Picea glauca from three sites over a distance of 500 km in Alaska (USA). We analysed Illumina-generated ITS2 sequences to relate mycobiome data with phenotypic tree traits, measures of genetic variation and climate variables obtained from long-term monitoring of the sites. Alpha-diversity declined with increasing environmental stress/climate harshness. Fungal communities differed in richness and taxonomic composition between sites, with a pronounced difference in the relative abundance of OTUs assigned to species of the rust genus Chrysomyxa, plant pathogens which seem to have been in an outbreak at two sites at the time of sampling. Beside climate parameters, needle age was the second strongest explanatory variable of the mycobiome composition, whereas we found no effect of tree genetic variation, indicating that environmental and tree trait specific variables mainly determined individual white spruce mycobiomes at Alaska's treelines.

A phenotype is the expression of interactions between species genotype and environment. We quantified the contributions of ecological and phylogenetic associations to phenotypic variation in Geosmithia fungi. Geosmithia are symbiotic beetle-associated saprotrophs with a range of life histories and host specificities, including obligate nutritional beetle mutualists (ambrosia fungi) and phytopathogens. We hypothesized that: (1) species phenotypes are better explained by their ecology than by their phylogenetic relationships; (2) niche specialization was accompanied by enzymatic capability losses; and (3) ambrosia Geosmithia species have higher nutritional quality and antibiotic capabilities than species with facultative symbioses. Our results confirmed that long-term co-evolved specialists have reduced metabolic breadth in comparison to generalists. Phytopathogenic G. morbida produces unique enzyme suites with affinity to ligno-cellulose. Mycelia of ambrosia fungi contain large amounts of oleic fatty acid with nutritive and possibly allelopathic function. Overall, our results indicate that Geosmithia ecology have greater effect on species phenotype than their phylogenetic relationships.

Entomopathogenic fungi routinely kill their hosts before releasing infectious spores, but a few species keep insects alive while sporulating, which enhances dispersal. Transcriptomics- and metabolomics-based studies of entomopathogens with post-mortem dissemination from their parasitized hosts have unraveled infection processes and host responses. However, the mechanisms underlying active spore transmission by Entomophthoralean fungi in living insects remain elusive. Here we report the discovery, through metabolomics, of the plant-associated amphetamine, cathinone, in four Massospora cicadina-infected periodical cicada populations, and the mushroom-associated tryptamine, psilocybin, in annual cicadas infected with Massospora platypediae or Massospora levispora, which likely represent a single fungal species. The absence of some fungal enzymes necessary for cathinone and psilocybin biosynthesis along with the inability to detect intermediate metabolites or gene orthologs are consistent with possibly novel biosynthesis pathways in Massospora. The neurogenic activities of these compounds suggest the extended phenotype of Massospora that modifies cicada behavior to maximize dissemination is chemically-induced.

The community assembly of wood-inhabiting fungi follows a successional pathway, with newly emerging resource patches being colonised by pioneer species, followed by those specialised on later stages of decay. The primary coloniser species have been suggested to strongly influence the assembly of the later-arriving community. We created an artificial resource pulse and studied the assembly of polypores over an 11yr period to ask how the identities of the colonising species depend on the environmental characteristics and the assembly history of the dead wood unit. Our results support the view that community assembly in fungi is a highly stochastic process, as even detailed description of the characteristics of dead wood (host tree species, size, decay class of the resource unit, its bark cover and how sunken it is to the ground) and the prior community structure provided only limited predictive power on the newly colonising species. Yet, we identified distinct links between primary and secondary colonising species and showed how the spatial aggregation of dead wood had a great impact on the community assembly.

Endophytes may play important roles in phytoremediation; however, little information is available on the endophytes of phosphorus (P)-accumulating plants and their potential application in P-phytoextraction. Here, 30 endophytic fungi were isolated from Polygonum hydropiper and classified into 24 taxonomic groups, with 76.7% being Ascomycota and 23.3% being Basidiomycota. Metarhizium anisopliae, Guignardia mangiferae and Phaeophlebiopsis peniophoroides were the dominant species. The Simpson and Shannon diversity indices were higher in shoots than in roots. The isolates had varied plant-growth-promoting traits with all being indole-3-acetic acid positive and only 18 exhibiting siderophore activities. P solubilization capability varied with fungal species and P sources; it correlated negatively with pH but positively with organic acids in a tricalcium phosphate medium. However, in a phytin medium, it did not correlate with pH, but positively with phosphatase activities. Five endophytes were found to have the greatest potential as inoculants to assist P. hydropiper in future P-phytoextraction studies.

Arbuscular mycorrhizal (AM) fungi in both soil and roots were examined in May (summer) and December (winter) under a 4-y drought experiment in a Chinese subtropical secondary forest. Drought significantly decreased AM fungal extra-radical hyphal density, spore density, and root colonization rate in both seasons. These AM parameters were significantly higher in summer than in winter in the control treatment, but only AM fungal extra-radical hyphal density exhibited the same seasonal trend in the drought treatment. In total, 45 AM fungal operational taxonomic units (OTUs) were obtained at a 97% sequence similarity level using Illumina sequencing of 18S rDNA. Drought and season had no significant effects on AM fungal OTU richness in soil and roots. AM fungal community composition in soil and roots was significantly affected by season but not by drought. This finding enhances our understanding of the response of AM fungi to global climate change in subtropical forest ecosystems.

Fungi are an important component of microbial communities and are well known for their ability to decompose refractory, highly polymeric organic matter. In soils and aquatic systems, fungi play an important role in carbon processing, however, their diversity, community structure and function as well as ecological role, particularly in groundwater, are poorly studied. The aim of this study was to examine the fungal community composition, diversity and function in groundwater from 16 boreholes located in the vicinity of two lakes in NE Germany that are characterized by contrasting trophic status. The analysis of 28S rRNA gene sequences amplified from the groundwater revealed high fungal diversity and clear differences in community structure between the aquifers. Most sequences were assigned to Ascomycota and Basidiomycota, but members of Chytridiomycota, Cryptomycota, Zygomycota, Blastocladiomycota, Glomeromycota and Neocallimastigomycota were also detected. In addition, 27 species of fungi were successfully isolated from the groundwater samples and tested for their ability to decompose complex organic polymers – the predominant carbon source in the groundwater. Most isolates showed positive activities for at least one of the tested polymer types, with three strains, belonging to the genera Gibberella, Isaria and Cadophora, able to decompose all tested substrates. Our results highlight the high diversity of fungi in groundwater, and point to their important ecological role in breaking down highly polymeric organic matter in these isolated microbial habitats.

Microbes influence plant phenotypes but most known examples of this are from the study of below-ground microbes and plant disease modification. To examine the potential importance of phyllosphere microbes on non-disease related plant traits, we used sterile Arabidopsis clones to test the effects of foliar fungi on flowering phenology and reproductive allocation under conditions of varying water stress. We inoculated the sterile plants with fully-factorial combinations of four fungal isolates, then measured flowering time and reproductive allocation for each treatment group under normal and water-stressed conditions. All plants inoculated with foliar fungi had significantly later flowering and greater seed mass than the sterile control groups. The magnitude of this effect depended on the specific fungi present, but individual fungal effects diminished as inoculum richness increased. Above-ground microbes likely influence other plant traits as well and should be considered in any study measuring plant phenotypes.

Fungal nodules and aged fungus gardens are products of termite fungiculture systems, and are the diets of termites. To understand the nutrition flow in fungiculture, we quantified the number and mass of fungal nodules produced along with fungus garden maturation and analysed the α-amino acid and fatty acid compositions of fungal nodules, fungus gardens, and termite tissues of a fungus-growing termite, Odontotermes formosanus. 1 g of fungus garden produced 5,148 fungal nodules (∼68.0 mg). Approximately 7.0% of α-amino acids were allocated to the fungal nodules and the rest (∼93.0%) remained in the fungus gardens. The compositions of α-amino acids or fatty acids in aged fungus gardens and fungal nodules were more similar to that of termite tissues than fresh fungus gardens, which supports the idea that termites nutritionally depend on the fungal products. Among the 18 α-amino acids, tryptophan was an essential amino acid and was the only one missing from fresh and aged fungus gardens, but found in fungal nodules at significantly higher concentrations. Hence, termites must consume fungal nodules to obtain tryptophan for survival. Furthermore, the fungus spores incorporated in nodules, were transferred when nodules were ingested by termites. We propose that allocating tryptophan in fungal nodules is crucial to enhance the mutualism between the fungus and termite.

Fungi historically placed in the iconic genera of Boletus, Leccinum and Xerocomus have been the subject of major taxonomic revisions in recent years. Yet, despite all advancements in systematics, boletoid fungi in insular ecosystems remain little explored and our knowledge of their diversity, distribution and abundance in Mediterranean ecoregions is far from complete. To shed light on this blind spot, the findings of a ten-year study from the island of Cyprus were analysed, integrating phylogenetic, ecological, morphological, phenological and chorological data. An unexpected diversity of Boletaceae fungi is unveiled, with twenty-five species phylogenetically confirmed to be present on the island, thirteen of them previously unreported. Sequencing of the ITS rDNA region, reveals crypticism within the Butyriboletus fechtneri, Caloboletus radicans, Rubroboletus lupinus and Rheubarbariboletus armeniacus species-complexes and infrageneric relationships are discussed. A strong link between boletoid fungi and Mediterranean oaks of the ilicoid group (Quercus alnifolia, Quercus coccifera subsp. calliprinos) is illustrated, with nineteen species (76%) overall found to be strictly or broadly associated with evergreen oaks. In stark contrast, the semi-deciduous Quercus infectoria subsp. veneris appears to be an unfavorable host for boletoid fungi, with just a single associated species so far. Phenological and chorological records indicate that most species on the island are rare, highly localized and fruit during very brief spells several years apart, mainly in response to increased annual, late summer or early autumn precipitation. The conservation status of these high-profile fungi is hence discussed, particularly in view of alarming climate changes, forecasted to have a dramatic impact on Mediterranean ecosystems in the years to come.

We studied the changes in the wood-inhabiting fungal communities on dead wood of Scots pine (Pinus sylvestris) under varying duration and intensity of cormorant nesting. The activities of the birds created large amounts of dead wood, changed wood chemistry and altered stand characteristics. Analyses based on records of fruiting structures of fungi showed that fungal communities in the cormorant colony differed from communities in unaffected forest. Ornithogenic factors impacted least on generalist species and promoted the occurrence of fungi uncharacteristic of coniferous wood or wood in general. The rate of ornithogenic change was rapid: a shift in fungal assemblages was evident by the third year of expansion of the bird colony into unaffected forest. It featured the disappearance of tremelloid fungi, a decline of corticioid fungi and an increase of hyphomycetoid fungi. The proportion of coniferous wood specialists decreased and that of generalists increased. It is expected that the changes in fungal communities will persist until the forest is fully regenerated.