Rasmus Kjøller

Bio: Rasmus Kjøller is an academic researcher from University of Copenhagen. The author has contributed to research in topics: Wood ash & Species richness. The author has an hindex of 35, co-authored 67 publications receiving 7105 citations. Previous affiliations of Rasmus Kjøller include Institut national de la recherche agronomique.

UNITE: a database providing web-based methods for the molecular identification of ectomycorrhizal fungi

Abstract: Identification of ectomycorrhizal (ECM) fungi is often achieved through comparisons of ribosomal DNA internal transcribed spacer (ITS) sequences with accessioned sequences deposited in public databases. A major problem encountered is that annotation of the sequences in these databases is not always complete or trustworthy. In order to overcome this deficiency, we report on UNITE, an open-access database. • UNITE comprises well annotated fungal ITS sequences from well defined herbarium specimens that include full herbarium reference identification data, collector/source and ecological data. At present UNITE contains 758 ITS sequences from 455 species and 67 genera of ECM fungi. • UNITE can be searched by taxon name, via sequence similarity using blastn, and via phylogenetic sequence identification using galaxie. Following implementation, galaxie performs a phylogenetic analysis of the query sequence after alignment either to pre-existing generic alignments, or to matches retrieved from a blast search on the UNITE data. It should be noted that the current version of UNITE is dedicated to the reliable identification of ECM fungi. • The UNITE database is accessible through the URL http://unite.zbi.ee

TRY plant trait database : Enhanced coverage and open access

Abstract: Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

Fungal community analysis by high-throughput sequencing of amplified markers - a user's guide

Abstract: Summary Novel high-throughput sequencing methods outperform earlier approaches in terms of resolution and magnitude. They enable identification and relative quantification of community members and offer new insights into fungal community ecology. These methods are currently taking over as the primary tool to assess fungal communities of plant-associated endophytes, pathogens, and mycorrhizal symbionts, as well as free-living saprotrophs. Taking advantage of the collective experience of six research groups, we here review the different stages involved in fungal community analysis, from field sampling via laboratory procedures to bioinformatics and data interpretation. We discuss potential pitfalls, alternatives, and solutions. Highlighted topics are challenges involved in: obtaining representative DNA/RNA samples and replicates that encompass the targeted variation in community composition, selection of marker regions and primers, options for amplification and multiplexing, handling of sequencing errors, and taxonomic identification. Without awareness of methodological biases, limitations of markers, and bioinformatics challenges, large-scale sequencing projects risk yielding artificial results and misleading conclusions.

High functional diversity within species of arbuscular mycorrhizal fungi

Abstract: Summary • Species of arbuscular mycorrhizal fungi (AMF) differ markedly in their improvement of plant nutrition and health. However, it is not yet possible to relate the diversity of an AMF community to its functional properties due to the lack of information on the functional diversity at each taxonomic level. This study investigates the inter- and intraspecific functional diversity of four Glomus species in relation to a phylogenetic analysis of large ribosomal subunit (LSU) sequences. • Growth and P nutrition of cucumber (Cucumis sativus) associated with 24 different isolates of AMF were measured in a two-compartment system with a 33P-labelled root-free soil compartment. • Intraspecific differences were found in plant growth response and the extension of the fungal mycelium into the root-free soil patch whereas length-specific P uptake of the hyphae remained rather constant within each AMF species. Hence, the length-specific P uptake differed according to species, whereas lower phylogenetic levels were required to match functional characteristics such as fungal growth pattern and plant growth promotion. • The large intraspecific diversity observed for mycelium growth and improvement of P uptake means that AMF communities of low species diversity may still contain considerable functional heterogeneity.

The Theory of Island Biogeography

Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

Towards a unified paradigm for sequence-based identification of fungi

Abstract: The nuclear ribosomal internal transcribed spacer (ITS) region is the formal fungal barcode and in most cases the marker of choice for the exploration of fungal diversity in environmental samples. Two problems are particularly acute in the pursuit of satisfactory taxonomic assignment of newly generated ITS sequences: (i) the lack of an inclusive, reliable public reference data set and (ii) the lack of means to refer to fungal species, for which no Latin name is available in a standardized stable way. Here, we report on progress in these regards through further development of the UNITE database (http://unite.ut.ee) for molecular identification of fungi. All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type (e.g. Hymenoscyphus pseudoalbidus|GU586904|SH133781.05FU), and their taxonomic and ecological annotations were corrected as far as possible through a distributed, third-party annotation effort. We introduce the term ‘species hypothesis’ (SH) for the taxa discovered in clustering on different similarity thresholds (97–99%). An automatically or manually designated sequence is chosen to represent each such SH. These reference sequences are released (http://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and in the QIIME pipeline. The system and the data will be updated automatically as the number of public fungal ITS sequences grows. We invite everybody in the position to improve the annotation or metadata associated with their particular fungal lineages of expertise to do so through the new Web-based sequence management system in UNITE.

Global diversity and geography of soil fungi

Abstract: 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.

Fungal endophytes: diversity and functional roles.

Abstract: Summary 1 Summary All plants in natural ecosystems appear to be symbiotic with fungal endophytes. This highly diverse group of fungi can have profound impacts on plant communities through increasing fitness by conferring abiotic and biotic stress tolerance, increasing biomass and decreasing water consumption, or decreasing fitness by altering resource allocation. Despite more than 100 yr of research resulting in thousands of journal articles, the ecological significance of these fungi remains poorly characterized. Historically, two endophytic groups (clavicipitaceous (C) and nonclavicipitaceous (NC)) have been discriminated based on phylogeny and life history traits. Here, we show that NC-endophytes represent three distinct functional groups based on host colonization and transmission, in planta biodiversity and fitness benefits conferred to hosts. Using this framework, we contrast the life histories, interactions with hosts and potential roles in plant ecophysiology of C- and NC-endophytes, and highlight several key questions for future work in endophyte biology.