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Because of their steep gradients in abiotic and biotic factors, mountains offer an ideal setting to illuminate the mechanisms that underlie patterns of species distributions and community assembly. We compared the composition of taxonomically and functionally diverse fungal communities in soils along five elevational gradients in mountains of the Neo- and Palaeotropics (northern Argentina, southern Brazil, Panama, Malaysian Borneo and Papua New Guinea). Both the richness and composition of soil fungal communities reflect environmental factors, particularly temperature and soil pH, with some shared patterns among neotropical and palaeotropical regions. Community dynamics are characterized by replacement of species along elevation gradients, implying a relatively narrow elevation range for most fungi, which appears to be driven by contrasting environmental preferences among both functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences in elevational patterns between neotropical and palaeotropical montane communities. The pronounced compositional and functional turnover along elevation gradients implies that tropical montane forest fungi will be sensitive to climate change, resulting in shifts in composition and functionality over time.

Two new species of Deconica with chrysocystidia are described from Australia and Mexico. Deconica milvispora, from a warm temperate rainforest in Queensland, Australia, is characterized by rhomboid basidiospores with nodulose angles not observed in any member of the genus until now. Deconica esperancensis, from a cloud forest in the south of Mexico, is characterized by subrhomboid basidiospores and short cheilocystidia. Full descriptions, illustrations, and comparisons with similar species are provided for both species. Bayesian and maximum likelihood analyses were performed employing sequences of nuc ITS rDNA, including seven new sequences from historical type collections of D. aequatoriae, D. alpestris, D. semiinconspicua, Deconica submaritima, D. thailandensis, D. umbrina, and Psilocybe subrunneocystidiata (= Deconica neorhombispora). As expected, the results showed the phylogenetic position of the new species described here within Deconica sect. Chrysocystidiatae, a supported monophyletic group. This section comprises many species, the majority with chrysocystidia, ten of them newly discovered but unnamed taxa. At this time, two taxa are described. Additionally, discussion of the traits found in the four major clades of Deconica is presented.

Many children spend considerable time in daycare centers and may here be influenced by indoor microorganisms, including fungi. In this study, we investigate the indoor mycobiome of 125 daycare centers distributed along strong environmental gradients throughout Norway. Dust samples were collected from doorframes outside and inside buildings using a citizen science sampling approach. Fungal communities in the dust samples were analyzed using DNA metabarcoding of the ITS2 region. We observed a marked difference between the outdoor and indoor mycobiomes. The indoor mycobiome included considerably more yeasts and molds compared to the outdoor samples, with Saccharomyces, Mucor, Malassezia and Penicillium among the most dominant fungal genera. Changes in the indoor fungal richness and composition correlated to numerous variables related to both outdoor and indoor conditions; there was a clear geographic structure in the indoor mycobiome composition that mirrored the outdoor climate, ranging from humid areas in western Norway to drier and colder areas in eastern Norway. Moreover, the number of children in the daycare centers, as well as various building features, influenced the indoor mycobiome composition. We conclude that the indoor mycobiome in Norwegian daycare centers is structured by multiple factors and is dominated by yeasts and molds. This study exemplifies how citizen science sampling enables DNA-based analyses of a high number of samples covering wide geographic areas.ImportanceWith an alarming increase in chronic diseases like childhood asthma and allergies, there is an increased focus on the exposure of young children to indoor biological and chemical air pollutants. Our study of 125 daycares throughout Norway demonstrates that the indoor mycobiome not only reflects co-occurring outdoor fungi but includes a high abundance of yeast and mold fungi with an affinity for indoor environments. A multitude of factors influence the indoor mycobiome in daycares, including building type, inhabitants, as well as the outdoor environment. Many of the detected yeasts and molds are likely associated with the human body, where some have been coupled to allergies and respiratory problems. Our results call for further studies investigating the potential impact of the identified daycare-associated mycobiomes on children health.

In the built environment, fungi can cause important deterioration of building materials and adverse health effects on occupants. Increased knowledge about indoor mycobiomes from different regions of the world, and their main environmental determinants, will enable improved indoor air quality management and identification of health risks. This is the first citizen science study about indoor mycobiomes at a large geographical scale in Europe, including 271 houses from Norway and 807 dust samples from three house compartments: outside of the building, living room and bathroom. The fungal community composition determined by DNA metabarcoding was clearly different between indoor and outdoor samples, but there were no significant differences between the two indoor compartments. The 32 selected variables, related to the outdoor environment, building features and occupant characteristics, accounted for 15% of the overall variation in community composition, with the house compartment as the key factor (7.6%). Next, the climate was the main driver of the dust mycobiomes (4.2%), while building and occupant variables had significant but minor influences (1.4% and 1.1%, respectively). The house-dust mycobiomes were dominated by ascomycetes (⁓70%) with Capnodiales and Eurotiales as the most abundant orders. Compared to the outdoor samples, the indoor mycobiomes showed higher species richness, which is probably due to the mixture of fungi from outdoor and indoor sources. The main indoor indicator fungi belonged to two ecological groups with allergenic potential: xerophilic molds and skin-associated yeasts. Our results suggest that citizen science is a successful approach for unraveling the built microbiome at large geographical scales.

Climate change causes upward shift of forest lines worldwide, with consequences on soil biota and carbon (C). Using a space-for-time approach, we analyse compositional changes in the soil biota across the forest line ecotone, an important transition zone between different ecosystems. We collected soil samples along transects stretching from subalpine mountain birch forests to low-alpine vegetation. Soil fungi and micro-eukaryotes were surveyed using DNA metabarcoding of the 18S and ITS2 markers, while ergosterol was used to quantify fungal biomass. We observed a strong shift in the soil biota across the forest line ecotone: Below the forest line, there were higher proportions of basidiomycetes and mucoromycetes, including ectomycorrhizal and saprotrophic fungi. Above, we observed relatively more root-associated ascomycetes, including Archaeorhizomycetes, ericoid mycorrhizal fungi and dark septate endophytes. Ergosterol and percentage C content in soil strongly and positively correlated with the abundance of root-associated ascomycetes. The predominance of ectomycorrhizal and saprotrophic fungi below the forest line likely promote high C turnover, while root-associated ascomycetes above the forest line may enhance C sequestration. With further rise in forest lines, there will be a corresponding shift in the belowground biota linked to C sequestration processes.

Soil depth represents a strong physiochemical gradient that greatly affects soil-dwelling microorganisms. Fungal communities are typically structured by soil depth, but how other microorganisms are structured is less known. Here, we tested whether depth-dependent variation in soil chemistry affects the distribution and co-occurrence patterns of soil microbial communities. This was investigated by DNA metabarcoding in conjunction with network analyses of bacteria, fungi, as well as other micro-eukaryotes, sampled in four different soil depths in Norwegian birch forests. Strong compositional turnover in microbial assemblages with soil depth was detected for all organismal groups. Significantly greater microbial diversity and fungal biomass appeared in the nutrient-rich organic layer, with sharp decrease towards the less nutrient-rich mineral zones. The proportions of copiotrophic bacteria, Arthropoda and Apicomplexa were markedly higher in the organic layer, while patterns were opposite for oligotrophic bacteria, Cercozoa, Ascomycota and ectomycorrhizal fungi. Network analyses indicated more intensive inter-kingdom co-occurrence patterns in the upper mineral layer (0–5 cm) compared to the above organic and the lower mineral soil, signifying substantial influence of soil depth on biotic interactions. This study supports the view that different microbial groups are adapted to different forest soil strata, with varying level of interactions along the depth gradient., This study highlights the importance of different soil horizons as well as a combination of markers when assessing microorganisms in forest soil and provide hypotheses about depth-dependent biotic interactions.

Background Children spend considerable time in daycare centers in parts of the world and are exposed to the indoor micro- and mycobiomes of these facilities. The level of exposure to microorganisms varies within and between buildings, depending on occupancy, climate, and season. In order to evaluate indoor air quality, and the effect of usage and seasonality, we investigated the spatiotemporal variation in the indoor mycobiomes of two daycare centers. We collected dust samples from different rooms throughout a year and analyzed their mycobiomes using DNA metabarcoding. Results The fungal community composition in rooms with limited occupancy (auxiliary rooms) was similar to the outdoor samples, and clearly different from the rooms with higher occupancy (main rooms). The main rooms had higher abundance of Ascomycota, while the auxiliary rooms contained comparably more Basidiomycota. We observed a strong seasonal pattern in the mycobiome composition, mainly structured by the outdoor climate. Most markedly, basidiomycetes of the orders Agaricales and Polyporales, mainly reflecting typical outdoor fungi, were more abundant during summer and fall. In contrast, ascomycetes of the orders Saccharomycetales and Capnodiales were dominant during winter and spring. Conclusions Our findings provide clear evidences that the indoor mycobiomes in daycare centers are structured by occupancy as well as outdoor seasonality. We conclude that the temporal variability should be accounted for in indoor mycobiome studies and in the evaluation of indoor air quality of buildings.

Climate change is causing upward shift of forest lines worldwide, with consequences for soil biota and carbon (C) sequestration. We here analyse compositional changes in the soil biota across the forest line ecotone, an important transition zone between different ecosystems. We collected soil samples along transects stretching from subalpine mountain birch forests to alpine heath. Soil fungi and micro-eukaryotes were surveyed using DNA metabarcoding of the ITS2 and 18S markers, while ergosterol was used to quantify fungal biomass. We observed a strong shift in the soil biota across the forest line ecotone: Below the forest line, there were higher proportions of basidiomycetes and mucoromycetes, including ectomycorrhizal and saprotrophic fungi. Above it, we observed relatively more root-associated ascomycetes, including Archaeorhizomycetes, ericoid mycorrhizal fungi and dark septate endophytes. Ergosterol and percentage C content in soil correlated strongly and positively with the abundance of root-associated ascomycetes. The predominance of ectomycorrhizal and saprotrophic fungi below the forest line probably promote high C turnover, while root-associated ascomycetes above the forest line may enhance C sequestration. With further rise in forest lines, there will be a corresponding shift in the below-ground biota, probably leading to enhanced release of soil C.

Plantations of Norway spruce have been established well beyond its natural range in many parts of the world, potentially impacting native microbial ecosystems and the processes they mediate. In this study, we investigate how the establishment of spruce plantations in a landscape dominated by native birch forests in western Norway impacts soil properties and belowground fungal communities. Soil cores were collected from neighboring stands of planted spruce and native birch forests. We used DNA metabarcoding of the rDNA internal transcribed spacer 2 region and ergosterol measurements to survey the fungal community composition and its biomass, respectively. In the two investigated soil layers (litter and humus), fungal community composition, diversity and biomass were strongly affected by the tree species shift. Native birch stands hosted markedly richer fungal communities, including numerous fungi not present in planted spruce stands. In contrast, the spruce stands included higher relative abundance of ectomycorrhizal fungi as well as higher fungal biomass. Hence, establishing plantations of Norway spruce in native birch forests leads to significant losses in diversity, but increase in biomass of ectomycorrhizal fungi, which could potentially impact carbon sequestration processes and ecosystem functioning., Establishing spruce plantations in native birch forest areas causes dramatic changes in belowground fungal communities.

The arctic tundra is undergoing climate-driven changes and there are serious concerns related to the future of arctic biodiversity and altered ecological processes under possible climate change scenarios. Arctic land surface temperatures and precipitation are predicted to increase further, likely causing major transformation in terrestrial ecosystems. As a response to increasing temperatures, shifts in vegetation and soil fungal communities have already been observed. Little is known, however, how long-term experimental warming coupled with increased snow depth influence the trajectories of soil fungal communities in different tundra types. We compared edaphic variables and fungal community composition in experimental plots simulating the expected increase in summer warming and winter snow depth, based on DNA metabarcoding data. Fungal communities in the sampled dry and moist acidic tundra communities differed greatly, with tundra type explaining ca. one-third of compositional variation. Furthermore, dry and moist tundra appear to have different trajectories in response to climate change. Specifically, while both warming and increased snow depth had significant effects on fungal community composition and edaphic variables in dry tundra, the effect of increased snow was greater. However, in moist tundra, fungal communities mainly were affected by summer warming, while increased snow depth had a smaller effect and only on some functional groups. In dry tundra, microorganisms generally are limited by moisture in the summer and extremely low temperatures in winter, which is in agreement with the stronger effect of increased snow depth relative to warming. On the contrary, moist tundra soils generally are saturated with water, remain cold year-round and show relatively small seasonal fluctuations in temperature. The greater observed effect of warming on fungi in moist tundra may be explained by the narrower temperature optimum compared to those in dry tundra.

DNA metabarcoding has become a powerful approach for analysing complex communities from environmental samples, but there are still methodological challenges limiting its full potential. While conserved DNA markers, like 16S and 18S, often are not able to discriminate among closely related species, other more variable markers - like the fungal ITS region, may include considerable intraspecific variation, which can lead to oversplitting of species during DNA metabarcoding analyses. Here we assessed the effects of intraspecific sequence variation in DNA metabarcoding by analysing local populations of eleven fungal species. We investigated the allelic diversity of ITS2 haplotypes using both Sanger sequencing and high throughput sequencing (HTS) coupled with error correction with the software dada2. All the eleven species, except one, included some level of intraspecific variation in the ITS2 region. Overall, we observed a high correspondence between haplotypes generated by Sanger sequencing and HTS, with the exception of a few additional haplotypes detected using either approach. These extra haplotypes, typically occurring in low frequencies, were probably due to PCR and sequencing errors or intragenomic variation in the rDNA region. The presence of intraspecific (and possibly intragenomic) variation in ITS2 suggest that haplotypes (or ASVs) should not be used as basic units in ITS-based fungal community analyses, but an extra clustering step is needed to approach species-level resolution.

Background: In the built environment, fungi can cause important deterioration of building materials and have adverse health effects on occupants. We here investigate what are the most important environmental variables (climate, building features or occupant characteristics) driving the indoor mycobiome structure and diversity in houses. We used Norway as study area since it spans a wide range of environmental gradients such as temperature and precipitation. We organized a large citizen science sampling campaign including 271 houses and 807 dust samples collected from three different house compartments: outside of the building, living room and bathroom. Fungal community composition and diversity were determined by DNA metabarcoding, and correlated to the environmental variables by multivariate statistical analyses.Results: The fungal community composition was clearly different between indoor and outdoor samples, but there were no significant differences between the two indoor compartments (i.e living room vs. bathroom). The 32 selected variables, related to the outdoor environment, building features and occupant characteristics, accounted for 15% of the overall variation in community composition, with the house compartment as the most important factor (7.6%). Next, the regional-scale climate was the main driver of the dust mycobiomes (4.2%), while building and occupant variables had significant but minor influences (1.4% and 1.1%, respectively). The house dust mycobiomes were mainly dominated by ascomycetes (⁓70%) with Capnodiales and Eurotiales as the most abundant orders. Compared to the outdoor, the indoor mycobiomes showed higher species richness, which is probably due to the mixture of fungi from outdoor and indoor sources. The main indoor indicator fungi belonged to two ecological groups with allergenic potential: xerophilic molds (mainly Penicillium and Aspergillus) and skin-associated yeasts (Malassezia, Debaryomyces, Candida and Rhodotorula).Conclusions: We show that indoor mycobiomes represent a mixture of fungi from indoor and outdoor sources, and that a multitude of indoor and outdoor variables structure indoor mycobiomes. We also demonstrate that citizen science is a successful and effective strategy to obtain samples for characterizing the indoor microbiomes at large geographical scales.

Arctic regions are experiencing the greatest changes of climate warming on the planet, and marked variations have already been observed in terrestrial arctic ecosystems. While most studies have focused on the effects of warming on arctic vegetation and nutrient cycling, little is known about how belowground communities, such as root-associated fungi, respond to warming. Similarly, there is also a gap in knowledge on how edible ectomycorrhizal fungal species will respond to climate changes. Here, we investigate how long-term summer warming affects ectomycorrhizal (ECM) fungal communities. We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without experimental warming over 18 years in both dry and moist tussock tundra in Alaska, USA. Warming had profound effects on community composition, abundance and, to a lesser extent, on richness of taxonomic and functional groups of ECM fungi. In addition, our data show that the direction and extent of response to warming tend to be species-specific and the reported compositional shifts in the community might affect nutrient cycling and soil organic C storage. We recommend that future studies on fungal communities and their roles in nutrient cycling take into account species-level responses.

Species from Entoloma subg. Entoloma are commonly recorded from both the Northern and Southern Hemispheres and, according to literature, most of them have at least Nearctic-Palearctic distributions. However, these records are based on morphological analysis, and studies relating morphology, molecular data and geographical distribution have not been reported. In this study, we used phylogenetic species recognition criteria through gene genealogical concordance (based on nuclear ITS, LSU, rpb2 and mitochondrial SSU) to answer specific questions considering species limits in Entoloma subg. Entoloma and their geographic distribution in Europe, North America and Australasia. The studied morphotaxa belong to sect. Entoloma, namely species like the notorious poisonous E. sinuatum (E. lividum auct.), E. prunuloides (type-species of sect. Entoloma), E. nitidum and the red-listed E. bloxamii. With a few exceptions, our results reveal strong phylogeographical partitions that were previously not known. For example, no collection from Australasia proved to be conspecific with the Northern Hemisphere specimens. Almost all North American collections represent distinct and sister taxa to the European ones. And even within Europe, new lineages were uncovered for the red-listed E. bloxamii, which were previously unknown due to a broad morphological species concept. Our results clearly demonstrate the power of the phylogenetic species concept to reveal evolutionary units, to redefine the morphological limits of the species addressed and to provide insights into the evolutionary history of key morphological characters for Entoloma systematics. New taxa are described, and new combinations are made, including E. fumosobrunneum, E. pseudoprunuloides, E. ochreoprunuloides and E. caesiolamellatum. Epitypes are selected for E. prunuloides and E. bloxamii. In addition, complete descriptions are given of some other taxa used in this study for which modern descriptions are lacking, viz. E. subsinuatum, E. whiteae, E. flavifolium, E. luridum, E. bloxamii, E. madidum, E. corneri, E. callidermum and E. coeruleoviride.

Summary The distribution patterns of tropical ectomycorrhizal (ECM) fungi along altitudinal gradients remain largely unknown. Furthermore, despite being an iconic site for biodiversity research, virtually nothing is known about the diversity and spatial patterns of fungi on Mt Kinabalu and neighbouring mountain ranges. We carried out deep DNA sequencing of soil samples collected between 425 and 4000 m above sea level to compare richness and community composition of ECM fungi among altitudinal forest types in Borneo. In addition, we tested whether the observed patterns are driven by habitat or by geometric effect of overlapping ranges of species (mid-domain effect). Community composition of ECM fungi was strongly correlated with elevation. In most genera, richness peaked in the mid-elevation montane forest zone, with the exception of tomentelloid fungi, which showed monotonal decrease in richness with increasing altitude. Richness in lower-mid- and mid-elevations was significantly greater than predicted under the mid-domain effect model. We provide the first insight into the composition of ECM fungal communities and their strong altitudinal turnover in Borneo. The high richness and restricted distribution of many ECM fungi in the montane forests suggest that mid-elevation peak richness is primarily driven by environmental characteristics of this habitat and not by the mid-domain effect.

Clitopilus reticulosporus (Entolomataceae, Agaricales) growing on rotting wood is described as a new species based on collections from Austria and Hungary. Multi-gene phylogenetic analysis of ITS, rpb2, LSU and mtSSU confirms the placement of C. reticulosporus in the Clitopilus-Rhodocybe clade in the Entolomataceae. It is nested within the subclade containing the species with clitopiloid spores (Clitopilus s. str.). Scanning electron microscopy studies demonstrate that the spores of this species have a peculiar reticulate ornamentation resembling an intermediate form between the clitopiloid type with longitudinal ribs, and the rhodocyboid type with irregular bumps and ridges. However, our ancestral character reconstruction suggests that (1) this character state is not an intermediate form and (2) the discovery of this new character state does not have a direct implication on the Entolomataceae spore evolution theory. Our phylogenetic reconstruction uncovered, at least, three distinct lineages in the Clitopilus s. str. clade, and suggest that sect. Clitopilus is monophyletic, while sect. Schyphoides and sect. Pleurotelloides are not.

© 2016 The Authors Climate warming leads to more intensive evaporation from the Arctic sea resulting in increased precipitation in the low Arctic, e.g., higher snowfall during winter. Deeper snow keeps the arctic soils warmer and alters soil attributes and vegetation, e.g., increase in nitrogen availability, expansion of shrubs and decline in shade-intolerant lichens and bryophytes. Changes in soil properties and vegetation are expected to influence on saprotrophic and plant-symbiotic fungi, but how increased snow depth affects their community composition remain unknown. In the present work, we used DNA metabarcoding to study the effects of long-term experimental manipulations of snow depth on soil fungal communities in dry heath and moist tussock tundra in Arctic Alaska. We report strong changes in fungal community compositions in the two tundra types, with pronounced declines observed in the majority of fungal functional guilds, including ectomycorrhizal, lichenized, plant pathogenic, saprotrophic and bryophyte-associated species. The observed changes in lichenized and bryophyte-associated fungi are in agreement with previously published above-ground changes, i.e. decrease of lichen and bryophyte cover and diversity. However, the majority of observed trends, including the decline of ectomycorrhizal fungi (that were anticipated to benefit from the expansion of their host plants), suggest that changes in fungal communities do not entirely correspond to and are not primarily driven by shifts in vegetation. Instead, arctic fungal communities appear to exhibit faster turnover that may be influenced by dynamic interactions with numerous biotic and abiotic factors, e.g., soil nutrient cycling and community dynamics in other groups of soil microorganisms. We highlight the importance of “below-ground studies” in assessing ecosystem responses to climatic changes, because faster turnover of microbial communities may be applicable for monitoring early-stage alterations caused by climatic changes. publisher: Elsevier articletitle: Compositional and functional shifts in arctic fungal communities in response to experimentally increased snow depth journaltitle: Soil Biology and Biochemistry articlelink: http://dx.doi.org/10.1016/j.soilbio.2016.06.001 content_type: article copyright: © 2016 The Authors. Published by Elsevier Ltd. ispartof: Soil Biology & Biochemistry vol:100 pages:201-209 status: published

Many arctic ecological processes are regulated by soil temperature that is tightly interconnected with snow cover distribution and persistence. Recently, various climate-induced changes have been observed in arctic tundra ecosystems, e.g. shrub expansion, resulting in reduction in albedo and greater C fixation in aboveground vegetation as well as increased rates of soil C mobilization by microbes. Importantly, the net effects of these shifts are unknown, in part because our understanding of belowground processes is limited. Here, we focus on the effects of increased snow depth, and as a consequence, increased winter soil temperature on ectomycorrhizal (ECM) fungal communities in dry and moist tundra. We analyzed deep DNA sequence data from soil samples taken at a long-term snow fence experiment in Northern Alaska. Our results indicate that, in contrast with previously observed responses of plants to increased snow depth at the same experimental site, the ECM fungal community of the dry tundra was more affected by deeper snow than the moist tundra community. In the dry tundra, both community richness and composition were significantly altered while in the moist tundra, only community composition changed significantly while richness did not. We observed a decrease in richness of Tomentella, Inocybe and other taxa adapted to scavenge the soil for labile N forms. On the other hand, richness of Cortinarius, and species with the ability to scavenge the soil for recalcitrant N forms, did not change. We further link ECM fungal traits with C soil pools. If future warmer atmospheric conditions lead to greater winter snow fall, changes in the ECM fungal community will likely influence C emissions and C fixation through altering N plant availability, fungal biomass and soil-plant C-N dynamics, ultimately determining important future interactions between the tundra biosphere and atmosphere. ispartof: Global Change Biology vol:22 issue:9 pages:3080-3096 ispartof: location:England status: published

Tropical mountains are hot spots of biodiversity and endemism,but the evolutionary origins of their unique biotas are poorlyunderstood. In varying degrees, local and regional extinction,long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it isdebated whether mountain endemics mostly originate from locallowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigatethe evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu inSabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), andcomprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shiftsfrom lower to higher vegetation zones in this latter group wererare. These insights could improve forecasts of the likelihood ofextinction and ‘evolutionary rescue in montane biodiversity hotspots under climate change scenarios.

Fungi, including symbionts, pathogens and decomposers, play crucial roles in community dynamics and nutrient cycling in terrestrial ecosystems. Despite their ecological importance, the response of most arctic fungi to climate warming is unknown, so are their potential roles in driving the observed and predicted changes in tundra communities. We carried out deep DNA sequencing of soil samples to study the long-term effects of experimental warming on fungal communities in dry heath and moist tussock tundra in Arctic Alaska. The data presented here indicate that fungal community composition responds strongly to warming in the moist tundra, but not in the dry tundra. While total fungal richness was not significantly affected by warming, there were clear correlations among operational taxonomic unit richness of various ecological and taxonomic groups and long-term warming. Richness of ectomycorrhizal, ericoid mycorrhizal and lichenized fungi generally decreased with warming, while richness of saprotrophic, plant and animal pathogenic, and root endophytic fungi tended to increase in the warmed plots. More importantly, various taxa within these functional guilds followed opposing trends that highlight the importance of species-specific responses to warming. We recommend that species-level ecological differences be taken into account in climate change and nutrient cycling studies that involve arctic fungi.

Arctic regions are experiencing the greatest rates of climate warming on the planet and marked changes have already been observed in terrestrial arctic ecosystems. While most studies have focused on the effects of warming on arctic vegetation and nutrient cycling, little is known about how belowground communities, such as fungi root-associated, respond to warming. Here, we investigate how long-term summer warming affects ectomycorrhizal (ECM) fungal communities. We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without long-term experimental warming in both dry and moist tussock tundra. Cortinarius was the most OTU-rich genus in the moist tundra, while the most diverse genus in the dry tundra was Tomentella. On the diversity level, in the moist tundra we found significant differences in community composition, and a sharp decrease in the richness of ECM fungi due to warming. On the functional level, our results indicate that warming induces shifts in the extramatrical properties of the communities, where the species with medium-distance exploration type seem to be favored with potential implications for the mobilization of different nutrient pools in the soil. In the dry tundra, neither community richness nor community composition was significantly altered by warming, similar to what had been observed in ECM host plants. There was, however, a marginally significant increase in OTUs identified as ECM fungi with the medium-distance exploration type in the warmed plots. Linking our findings of decreasing richness with previous results of increasing ECM fungal biomass suggests that certain ECM species are favored by warming and may become more abundant, while many other species may go locally extinct due to direct or indirect effects of warming. Such compositional shifts in the community might affect nutrient cycling and soil organic C storage. ispartof: Global Change Biology vol:21 issue:2 pages:959-972 ispartof: location:England status: published

Arctic tundra regions have been responding to global warming with visible changes in plant community composition, including expansion of shrubs and declines in lichens and bryophytes. Even though it is well known that the majority of arctic plants are associated with their symbiotic fungi, how fungal community composition will be different with climate warming remains largely unknown. In this study, we addressed the effects of long-term (18 years) experimental warming on the community composition and taxonomic richness of soil ascomycetes in dry and moist tundra types. Using deep Ion Torrent sequencing, we quantified how OTU assemblage and richness of different orders of Ascomycota changed in response to summer warming. Experimental warming significantly altered ascomycete communities with stronger responses observed in the moist tundra compared with dry tundra. The proportion of several lichenized and moss-associated fungi decreased with warming, while the proportion of several plant and insect pathogens and saprotrophic species was higher in the warming treatment. The observed alterations in both taxonomic and ecological groups of ascomycetes are discussed in relation to previously reported warming-induced shifts in arctic plant communities, including decline in lichens and bryophytes and increase in coverage and biomass of shrubs. ispartof: Molecular Ecology vol:24 issue:2 pages:424-437 ispartof: location:England status: published

Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.

We characterized fungal communities in dry and moist tundra and investigated the effect of long-term experimental summer warming on three aspects of functional groups of arctic fungi: richness, community composition and species abundance. Warming had profound effects on community composition, abundance, and, to a lesser extent, on richness of fungal functional groups. In addition, our data show that even within functional groups, the direction and extent of response to warming tend to be species-specific and we recommend that studies on fungal communities and their roles in nutrient cycling take into account species-level responses.

This study focuses on intra-articular (IA) drug delivery system for the treatment of knee osteoarthritis (OA). In osteoarthritic condition the synovial fluid presents pockets with lower pH environment. To take advantage of these pH differences, poly(lactic-co-glycolic acid (PLGA) nanoparticles (NPs) and pH- responsive PLGA NPs encapsulated with ammonium bicarbonate (NH4HCO3) were generated. The nanoparticles were loaded with hyaluronic acid (HA) as a possible model drug for OA and with near-infrared dye (NIR) that was used to visualize the NPs with molecular imaging techniques. These NPs were characterized by dynamic light scattering, transmission electron microscopy and compared in in vitro, in vivo and ex vivo experiments in the treatment of OA. The results indicate that the NPs were sufficiently small, displayed a uniform size distribution and were non-toxic both in vitro and in vivo. Both NPs treatment seem to induced a reduction in OA progression, with pH- responsive NPs showing the more pronounced effect. This is probably because the pockets of low pH environment in the synovial fluid trigger a burst release of the pH-responsive NPs. This result is corroborated by in vitro experiments since the pH- responsive NPs showed an extracellular burst release behavior and higher chondrocyte vitality than non-responsive NPs. This study demonstrates that PLGA NPs containing HA and NH4HCO3 are candidates for the treatment of knee OA.

Fungi play integral roles in soil nutrient cycling, but the determinants of fungal diversity and biogeographic patterns of key functional groups remain poorly understood. By using pyrosequencing data from hundreds of globally distributed soil samples, we demonstrated fungal diversity that expands upon the taxonomic and molecular diversity recorded so far. Except for ectomycorrhizal symbionts, fungal functional group richness was unrelated to plant diversity and plant-to-fungus richness ratio declined exponentially towards the poles. Climatic factors, followed by edaphic and spatial variables, constituted the best predictors of fungal richness and community composition at the global scale. Fungi follow general biogeographic patterns and latitudinal diversity gradients with several exceptions. Fil: Tedersoo, Leho. University Of Tartu.; Estonia Fil: Bahram, Mohammad. University Of Tartu.; Estonia Fil: Põlme, Sergei. University Of Tartu.; Estonia Fil: Kõljalg, Urmas. University Of Tartu.; Estonia Fil: Yorou, Nourou. Université de Parakou. Faculté d′Agronomie; Benín Fil: Nouhra, Eduardo Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Greslebin, Alina Gabriela. Universidad Nacional de la Patagonia; Argentina Fil: Kohout, Petr. University Of Tartu.; Estonia Fil: Hosaka, Kentaro. National Museum of Nature and Science. Department of Botany; Japón Fil: Hiiesalu, Indrek. University Of Tartu.; Estonia Fil: Henkel, Terry W.. Humboldt State University. Department of Biological Sciences; Estados Unidos Fil: Harend, Helery. University Of Tartu.; Estonia Fil: Guo, Liang-dong. Chinese Academy of Sciences. Institute of Microbiology. State Key Laboratory of Mycology; China Fil: Geml, József. Fil: Grelet, Gwen. Landcare Research. Ecosystems and Global Change Team; Nueva Zelanda Fil: Gates, Genevieve. Tasmanian Institute of Agriculture; Australia Fil: Dunstan, William. Murdoch University. School of Veterinary and Life Sciences; Australia Fil: Dunk, Chris. Swedish University of Agricultural Sciences. Department of Forest Ecology and Management; Suecia Fil: Drenkhan, Rein. Estonian University of Life Sciences. Institute of Forestry and Rural Engineering; Estonia Fil: Dearnaley, John. University of Southern Queensland. Faculty of Health, Engineering and Sciences; Australia Fil: De Kesel, André. Botanic Garden Meise; Bélgica Fil: Dang,Tan. Vietnamese Academy of Forest Sciences; Vietnam Fil: Chen, Xin. Zhejiag University. College of Life Sciences; China Fil: Buegger, Franz. Helmholtz Zentrum München. Institute of Soil Ecology; Alemania Fil: Brearley, Francis Q.. Manchester Metropolitan University. School of Science and the Environment; Reino Unido Fil: Bonito, Gregory. Royal Botanic Gardens Melbourne; Australia Fil: Anslan, Sten. University Of Tartu.; Estonia Fil: Abell, Sandra. James Cook University. School of Marine and Tropical Biology; Australia Fil: Abarenkov, Kessy. University Of Tartu.; Estonia