443 research outputs found
Terricolous lichens in the glacier forefield of the Morteratsch glacier (Eastern Alps, Graubünden, Switzerland)
No full textThree sampling sites were established at increasing distance from the Morteratsch glacier to investigate lichen communities on soil in the glacier forefield. The survey yielded 13 lichen species and one lichenicolous fungus. Peltigera extenuata (NYL. ex VAIN.) LOJKA (Peltigerales) is new to the canton of Graubünden
Terricolous lichens in the glacier forefield of the Pasterze (Eastern Alps, Carinthia, Austria)
No full textThe investigation of lichens on soil, plant debris and terricolous mosses in the glacier forefield of the Pasterze yielded 35 lichen species. Placidiopsis oreades Breuss (Verrucariales) is new to Austria. Three sampling sites were established at increasing distance from the glacier, in order to compare species diversity, abundance and composition within the forefield and with four other glacier forefields of the Eastern Alps. We would like to thank the administration of the National Park Hohe Tauern Carinthia and the Amt der Kärntner Landesregierung (Abteilung 8) for supporting our request for a scientific collecting permit, the Bezirkshauptmannschaft Spittal an der Drau (Bereich 10) for making out the permit, Peter KOSNIK for the TLC, Othmar BREUSS for the confirmation of Placidiopsis oreades, and Christian SCHEUER as well as Herwig TEPPNER for critically reading the manuscript and general remarks. Financial support from the Austrian Science Fund (FWF project P25078-B16) and the University of Graz is gratefully acknowledged
Assembly patterns of soil-dwelling lichens after glacier retreat in the European Alps
No full textAim: To assess the spatial-temporal dynamics of primary succession following deglaciation in soil-dwelling lichen communities. Location: European Alps (Austria, Switzerland and Italy). Methods: Five glacier forelands subjected to relevant glacier retreat during the last century were investigated. In each glacier foreland, three successional stages were selected at increasing distance from the glacier, corresponding to a gradient of time since deglaciation between 25 and 160 years. In each successional stage, soil-dwelling lichens were surveyed within five 1 × 1 m plots. In addition to a classical ecological framework, based on species richness and composition, we applied a functional approach to better elucidate community assembly mechanisms. Results: A positive relationship was found between species richness and time since deglaciation indicating that richer lichen communities can be found at increasing terrain ageing. This pattern was associated with compositional shifts, suggesting that different community assemblages can be found along the successional stages. The analysis of β-diversity revealed a significant nested pattern of species assemblages along the gradient (i.e. earlier successional stages hosted a subset of the species already established in older successional stages), while the turnover component was less relevant. Considering functional groups, we found contrasting patterns in relation to time since deglaciation: the incidence of species with a cyanobacterial photobiont and those reproducing by spores decreased, while that of species reproducing by vegetative propagules increased. Main conclusions: This study reveals that community assembly patterns of soil-dwelling lichens in alpine glacier forelands are ruled by mechanisms of directional species accumulation and trait selection that involve a trade-off between different functional strategies. Functional traits that reflect the dispersal and adaptation capability of the species underpin the colonization success of soil-dwelling lichens in glacier forelands
Terricolous lichens in the glacier forefield of the Rötkees (Eastern Alps, South Tyrol, Italy)
No full textThe investigation of lichens on soil, plant debris and terricolous mosses in the glacier forefield of the Rötkees yielded 31 lichen taxa (29 species and 2 varieties) and one lichenicolous fungus. Micarea incrassata HEDL. (Lecanorales) is new to Italy. Three sampling sites were established at increasing distance from the glacier, in order to compare species diversity, abundance and composition
Terricolous lichens in the glacier forefield of the gaisbergferner (Eastern Alps, Tyrol, Austria)
No full textThe investigation of lichens on soil, plant debris and terricolous mosses in the glacier forefield of the Gaisbergferner yielded 41 lichen taxa (39 species and 2 varieties) and one lichenicolous fungus. Three sampling sites were established at increasing distance from the glacier, in order to compare species diversity, abundance and composition
Towards a checklist of the lichens of the Alps
No full textThe Alps are one of the largest continuous natural areas in Europe, stretching approximately 1,200 kilometres across eight countries, and including fourteen national parks. The Alpine Convention emphasizes the importance of this area and encourages transnational research and conservation projects. Lichens as unique models of fungal symbioses with macroscopically recognizable, light-exposed individuals are important colonizers of rock, soil and plant material, and they are a dominant symbiotic life form of higher altitudes in the Alps. National checklists or catalogues exist for Austria, France, Germany, Italy, Slovenia and Switzerland. The compilation of a catalogue of the lichenized fungi of the Alps is a long overdue task and will enable us to compare, for instance, the genera or species diversity of the Alps with those of other mountain systems of the world. We have summarized the abundant but scattered baseline information on lichen biodiversity in the Alps, which will lead to a transnational inventory of all lichen taxa (c. 3,000), including data on their horizontal and vertical distribution and their ecology. This information will be of use for experts, decision-makers, and citizen scientists
Impaired clearance of herpes simplex virus type 1 from mice lacking CD1d or NKT cells expressing the semivariant Valpha14-Jalpha 281 TCR
No full textCopyright © 2003 by The American Association of ImmunologistsAg-presenting molecule CD1 and CD1-restricted NKT cells are known to contribute to defense against a range of infectious pathogens, including some viruses. CD1-restricted NKT cells, a distinct subpopulation of T cells, have striking and rapid effector functions that contribute to host defense, including rapid production of IFN-y and IL-4, and activation of NK cells. Consideration of the important contributions of innate and adaptive immunity to clearance of HSV prompted us to investigate the role of CD1 and of NKT cells expressing the Vα14-Jα281 TCR in the pathogenesis of HSV infection. To address this issue, we compared infection in wild-type mice with that in CD1 gene knockout (GKO) and Jα281 GKO mice. In this study, we report impaired clearance of virus and viral Ags, and more florid acute infection in mice lacking CD1 (and by inference, CD1-restricted T cells), in comparison with parental C57BL6 mice. In Jα281 GKO mice there was also impairment of virus clearance, resembling that seen in CD1 GKO mice. These results imply roles for the Vα14-Jα281 subset of NKT cells and for CD1d in control of HSV infection.Branka Grubor-Bauk, Anthony Simmons, Graham Mayrhofer and Peter G. Spec
A hotspot of lichen diversity and lichenological research in the Alps: the Paneveggio-Pale di San Martino Natural Park (Italy)
No full textA checklist of 916 lichenised taxa is reported from the Paneveggio-Pale di San Martino Natural Park and its surroundings (Trentino-Alto Adige, N Italy), based on 7351 records from: (a) 72 literature sources, (b) eight public and private herbaria and (c) field observations by some of the authors. The study area appears as a hotspot of lichen diversity, hosting 30.1% of the lichen biota of the Alps in a territory that has 0.064% of their total surface area. This is mainly due to its high climatical, geological and orographic heterogeneity, but also to the long history of lichenological exploration, that started in the 19th century with Ferdinand Arnold and is still ongoing. The present work highlights the importance of detailed species inventories to support knowledge of biodiversity patterns, taxonomy and ecology and to properly address conservation issues. Fuscidea mollis var. caesioalbescens, Hydropunctaria scabra, Protoparmelia badia var. cinereobadia and Variospora paulii are new to Italy, 18 other taxa are new to Trentino-Alto Adige
Explainable Outlier Detection for Multivariate Functional Data
No full textThis work addresses the challenges of robust covariance estimation and interpretable outlier
detection for multivariate functional data with separable covariance structures. Our goal is to
develop a method that simultaneously improves robustness and interpretability in this context.
We establish a connection between stochastic processes with separable covariance structures
and the corresponding matrix-variate distribution of their basis representations. Leveraging this
connection, we employ the Matrix Minimum Covariance Determinant (MMCD) approach introduced by [Mayrhofer et al., 2024], in conjunction with a multivariate functional Mahalanobis
(semi-)distance introduced in [Galeano et al., 2015], to robustly estimate both mean and covariance functions for multivariate functional data. For interpretable outlier detection, we propose
a methodology that applies Shapley values from game theory to decompose overall outlyingness into component-specific contributions. Importantly, we reduce the otherwise exponential
computational complexity (relative to the number of components) to linear complexity, while
retaining the key properties of the Shapley value. This integrated framework—combining robust
Mahalanobis distances, MMCD estimators, and Shapley value-based outlyingness decomposition
provides a robust and interpretable approach for analyzing multivariate functional data with
separable covariance structures. The effectiveness of this approach is demonstrated through
both theoretical analysis and practical applications, including simulations and real-world case
studies
Explainable outlier detection for multivariate functional data based on a functional Mahalanobis distance
No full textThis work addresses the challenges of robust covariance estimation and interpretable outlier detection for multivariate functional data with separable covariance structures. Our goal is to develop a method that simultaneously improves robustness and interpretability in this context. We establish a connection between stochastic processes with separable covariance structures and the corresponding matrix-variate distribution of their basis representations. Leveraging this connection, we employ the Matrix Minimum Covariance Determinant (MMCD) approach introduced by [Mayrhofer et al., 2024], in conjunction with a multivariate functional Mahalanobis (semi-)distance introduced in [Galeano et al., 2015], to robustly estimate both mean and covariance functions for multivariate functional data. For interpretable outlier detection, we propose a methodology that applies Shapley values from game theory to decompose overall outlyingness into component-specific contributions. Importantly, we reduce the otherwise exponential computational complexity (relative to the number of components) to linear complexity, while retaining the key properties of the Shapley value. This integrated framework—combining robust Mahalanobis distances, MMCD estimators, and Shapley value-based outlyingness decomposition provides a robust and interpretable approach for analyzing multivariate functional data with separable covariance structures. The effectiveness of this approach is demonstrated through both theoretical analysis and practical applications, including simulations and real-world case studies
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