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Diversity and community composition of root-associated fungi explored by high throughput sequencing
No full textInteractions between plant roots and fungi are well known from most terrestrial ecosystems. Mycorrhizal association is the most prominent plant-fungi interaction, where the fungal partners increase the water and nutrient uptake of their host plants. This symbiosis might be especially important in marginal habitats like arctic and alpine environments. The structure, diversity and spatial patterns of the root-associated fungal communities are to a large extent unknown due to previous methodological limitations. The main objective in this thesis was to implement high throughput DNA sequencing to assess the community structure, richness and spatial distribution of root-associated fungal communities in arctic and alpine environments. We focused on one host plant species, namely the ectomycorrhizal herb Bistorta vivipara. Its small and condensed root system enabled us to analyze the entire fungal assemblages associated with individual root systems, using 454 pyrosequencing of ITS1 and/or ITS2 amplicons. All the five studies included in this thesis revealed that the most prominent fungal groups were well-known ectomycorrhizal fungi such as Agaricales, Sebacinales and Thelephorales. Furthermore, ascomycete fungi of the order Helotiales were also recovered frequently across all root systems. Although a high patchiness in fungal community composition generally was observed, some systematic compositional changes along gradients were observed. In a 2x2 m2 local scale study, a spatial autocorrelation was observed at small scales (<0.34 m). Furthermore, a significant compositional difference was observed between the rootassociated fungal communities and adjacent soil fungal communities. Along two primary succession gradients in arctic and alpine areas, a systematic compositional shift was observed. The fungal richness increased along the chronosequences towards the climax vegetation. In a biogeographic survey, where the root-associated fungi were analyzed across Svalbard, a compositional shift was observed that was associated with the latitudinal gradient. Moreover, the fungal richness increased westwards in the more climatic favorable habitats. Overall, the different studies indicate that stochastic processes, possibly related to aerial spore dispersal, are important during fungal community establishment. The conducted studies exemplify that high throughput sequencing is a powerful approach for analyzing complex microbial communities
Current knowledge of Chytridiomycota diversity in Northern Europe and future research needs
Get PDFChytridiomycota is the most species-rich phylum of basal lineage fungi involved in vital processes in both terrestrial and aquatic ecosystems. Still, the diversity and richness of this group remains cryptic. In Northern Europe, few species have been recorded despite the numerous intact lake systems covering this region. Recent classifications of early diverging fungal lineages differ considerably on the diversity of chytrid species and their taxonomic placement. Here, we present the current knowledge of the Chytridiomycota diversity within Northern Europe by using the Global Biodiversity Information Facility (GBIF) data and compare how this diversity distributes across two recently proposed classification systems. Furthermore, we illustrate how various sampling types are influencing the recorded classification levels. Lastly, we discuss how metabarcoding has contributed to the overall understanding of the Chytridiomycota diversity in revealing the “dark matter fungi”, and we point out future research needs in the field of aquatic mycology in the Nordic region
Epifyttregisterering av rødlistede lav og moser i Stavanger
Get PDFBlaalid, R. & Jokerud, M. 2018. Epifyttregistrering av rødlistede lav og moser i Stavanger. NINA Rapport 1503. Norsk institutt for naturforskning.
Rød- og svartelistet sopp, lav og moser ble registrert på 287 trær i Stavanger sentrum, nærmere bestemt i Kongsgata, Lagårdsveien og Hillevågsveien. Bakgrunnen for artsregistrering var den planlagt utvidelse av bussveien på strekningen fra Haugåsveien i Hillevåg via sentrum til Mos-vatnet. Data fra Artsdatabanken og GBIF Norge viser registreringer av 32 rød- og svartelistede arter i området.
Registeringene ble utført fra bakkenivå til ca. 180 cm høyde. Vi benyttet oss av Statens vegvesen sitt Vegkart (https://www.vegvesen.no/vegkart/) med funksjonen som viser trær for å identifisere hvert tre. Vi fant ingen svartelistede arter av moser, sopp eller lav på de undersøkte trærne. Vi fant en rødlistet mose (ynglehårsstjerne) og to rødlistede lav (kystbrunlav og grå punktlav). En av lavartene vi fant (grå punktlav), består muligens av to arter (inkludert grå punktlav og rand-punktlav). Disse to artene var umulig å skille og vi har derfor valgt å definere dette som et arts-kompleks grå punktlav cf. 60 trær hadde en rødlistet art, mens 6 trær hadde to rødlistede arter. Vi fant i tillegg en potensiell fremmed lavart på totalt 19 trær.
Våre funn viser at byområder er viktige habitater, også for sjeldne og truede arter. Vi anbefaler at det tas særlig hensyn til rødlistefunnene og at alternativer til trasevalg utredes for å kunne la trær med disse artene stå. Dersom det er umulig å bevare trærne, anbefaler vi at totalt ni trær flyttes til egnede lokaliteter for å bevare epifyttsamfunnet av rødlistede arter
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Habitat Protection Approaches Facilitate Conservation of Overlooked Fungal Diversity–A Case Study From the Norwegian Coastal Heathland System
Get PDFEuropean coastal heathlands are distinct ecosystems shaped by land use tradition and they have experienced an 80% area reduction from their historical maximum. These mosaics of mires and wind exposed patches have ericaceous shrub dominated vegetation, and soils within coastal heathlands are characterized by low pH and high levels of recalcitrant debris. Using a culture-based approach with molecular identification of isolates, we characterized root-associated fungal communities of six ericaceous species in eight heathland localities along Norway’s western coast. Site-level alpha diversity ranged from 21-38 OTUs, while the total estimated gamma diversity for culturable heathland root fungi was 190-231 OTUs. Most species recovered are previously reported at low abundance in Norway, suggesting the biodiversity in this community is underreported, rather than novel for science. The fungi recovered were primarily Ascomycota, specifically endophytic Phialocephala, and Pezicula, and no host specificity was observed in the communities. The fungal communities exhibited high turnover and low nestedness, both between ericaceous hosts and across heathland sites. We observed no spatial patterns in fungal betadiversity, and this heterogeneity may be a product of the unique historic land use practices at each locality creating a distinct mycofloral “fingerprint”. Robust diversity estimates will be key for managing fungal biodiversity in coastal heathlands. Our results indicate that sampling schemes that maximize the number of host plants sampled per site, rather than the number of cultures per plant yield improved alpha diversity estimates. Similarly, gamma diversity estimates are improved by maximizing the total number of localities sampled, rather than increasing the number of plants sampled per locality. We argue that while the current protected status of coastal heathland habitats and restoration efforts have knock-on effects for the conservation of fungal biodiversity, fungi have a vital functional role in the ecosystem and holistic conservation plans that consider fungal biodiversity would be beneficial. coastal heathland, mycoflora, conservation, diversity, ericaceous fungi, root associated fungipublishedVersio
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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