38 research outputs found

    Hornworts of Australia: Three New Anthoceros L. (Anthocerotaceae) Species from New South Wales.

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    Three new species of Anthoceros sect. Fusiformes are described, all occurring on the North West Slopes and Plains of New South Wales and all sharing spore characteristics of a smooth unornamented strip either side of the triradiate mark on the proximal face. Illustrations and a distribution map are provided for all species, along with a key to Australian Anthocerotaceae

    Overlapping fern and Bryophyte hotspots: Assessing ferns as a predictor of Bryophyte diversity

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    Bryophytes are significant contributors to floristic diversity, but they are often neglected in field surveys and collections. Thus, in order to obtain more accurate estimates of plant richness, there must be reliable estimates of bryophyte diversity. To address this, we examined whether another plant group, namely the ferns, could be used as a surrogate for bryophytes. We used datasets spanning the entire Australian continent for mosses, liverworts, liverworts+hornworts, ferns, and conifers (hornworts were aggregated into the group liverworts+hornworts). Two measures of richness were examined across the continent (as 50 km × 50 km grid cells): uncorrected richness and sample-standardised richness. We calculated the correlations among richness of all of the groups to test the hypothesis that fern diversity predicts bryophyte diversity (because of shared ecological preferences) while conifer diversity does not. Conifers showed very little correlation to either of the four plant groups, whereas ferns were highly correlated to mosses and to a lesser extent to liverworts and liverworts+hornworts. Liverworts, as well as liverworts+hornworts, and mosses were also strongly correlated. These results indicate that surrogates can assist in estimating the diversity and the conservation of other poorly collected plant groups

    Fossombronia bracchia Cargill (Fossombroniaceae, Marchantiophyta), a new species from Western Australia

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    The new species, Fossombronia bracchia, from Lesueur National Park, an area of high vascular plant endemism and species richness in southwestern Western Australia, is described and illustrated; a distribution map is provided. The new species has strong morphological similarities to the South African species F. tumida

    Re-assessment of type material of Plagiothecium novae-seelandiae Broth. and descriptions of four new Plagiothecium taxa (Bryophyta, Plagiotheciaceae) from Australasia

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    A re-examination of the original collection of Plagiothecium novae-seelandiae described by Brotherus in 1916 indicated that this material is not homogeneous. Re-examination of the diagnosis of this species and morphological analysis supports that two separate taxa should be distinguished – Plagiothecium novae-seelandiae var. novae-seelandiae and P. novae-seelandiae var. brotheri var. nov. Also, comparisons with the original collection of Hypnum lamprostachys (= P. lamprostachys) showed differences, which supported their treatment as separate taxa. Revision of the genus Plagiothecium from Australasia (CANB, CHR, HO, MEL, WELT) and types of other species described from this part of the world (P. funale and P. lucidum) supported by the study of their diagnoses, qualitative and quantitative characteristics as well as mathematical analyses (PCA, HCA) allowed the division of the examined material into six separate groups – six separate taxa. Thereby, three distinct taxa are proposed – P. cordatum sp. nov., P. semimortuum sp. nov., and P. semimortuum var. macquariense var. nov. All taxa mentioned above are described in detail, their current known distribution and ecological preferences are also included. In addition, images illustrating their most important taxonomic features, as well as an original key to distinguish individual taxa are presented

    Contributions to the bryoflora of Australia, III. The genus nowellia mitt. (cephaloziaceae, jungermanniopsida)

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    The liverwort genus Nowellia Mitt. was previously unknown from the Australian continent. During a collecting trip by the authors in June of 2001 throughout northern Queensland, two species were found, the Laurasian Nowellia curvifolia (Dicks.) Mitt. from the cloud forest of Bellenden Kerr summit and the Malesian-Australasian Nowellia langii Pears. from the montane forests of Cardwell Range

    Implications of the 2019–2020 megafires for the biogeography and conservation of Australian vegetation

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    Australia's 2019–2020 'Black Summer' bushfires burnt more than 8 million hectares of vegetation across the south-east of the continent, an event unprecedented in the last 200 years. Here we report the impacts of these fires on vascular plant species and communities. Using a map of the fires generated from remotely sensed hotspot data we show that, across 11 Australian bioregions, 17 major native vegetation groups were severely burnt, and up to 67–83% of globally significant rainforests and eucalypt forests and woodlands. Based on geocoded species occurrence data we estimate that >50% of known populations or ranges of 816 native vascular plant species were burnt during the fires, including more than 100 species with geographic ranges more than 500 km across. Habitat and fire response data show that most affected species are resilient to fire. However, the massive biogeographic, demographic and taxonomic breadth of impacts of the 2019–2020 fires may leave some ecosystems, particularly relictual Gondwanan rainforests, susceptible to regeneration failure and landscape-scale decline

    Quantifying Phytogeographical Regions of Australia Using Geospatial Turnover in Species Composition

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    The largest digitized dataset of land plant distributions in Australia assembled to date (750,741 georeferenced herbarium records; 6,043 species) was used to partition the Australian continent into phytogeographical regions. We used a set of six widely distributed vascular plant groups and three non-vascular plant groups which together occur in a variety of landscapes/habitats across Australia. Phytogeographical regions were identified using quantitative analyses of species turnover, the rate of change in species composition between sites, calculated as Simpson's beta. We propose six major phytogeographical regions for Australia: Northern, Northern Desert, Eremaean, Eastern Queensland, Euronotian and South-Western. Our new phytogeographical regions show a spatial agreement of 65% with respect to previously defined phytogeographical regions of Australia. We also confirm that these new regions are in general agreement with the biomes of Australia and other contemporary biogeographical classifications. To assess the meaningfulness of the proposed phytogeographical regions, we evaluated how they relate to broad scale environmental gradients. Physiographic factors such as geology do not have a strong correspondence with our proposed regions. Instead, we identified climate as the main environmental driver. The use of an unprecedentedly large dataset of multiple plant groups, coupled with an explicit quantitative analysis, makes this study novel and allows an improved historical bioregionalization scheme for Australian plants. Our analyses show that: (1) there is considerable overlap between our results and older biogeographic classifications; (2) phytogeographical regions based on species turnover can be a powerful tool to further partition the landscape into meaningful units; (3) further studies using phylogenetic turnover metrics are needed to test the taxonomic areas

    World checklist of hornworts and liverworts

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    A working checklist of accepted taxa worldwide is vital in achieving the goal of developing an online flora of all known plants by 2020 as part of the Global Strategy for Plant Conservation. We here present the first-ever worldwide checklist for liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) that includes 7486 species in 398 genera representing 92 families from the two phyla. The checklist has far reaching implications and applications, including providing a valuable tool for taxonomists and systematists, analyzing phytogeographic and diversity patterns, aiding in the assessment of floristic and taxonomic knowledge, and identifying geographical gaps in our understanding of the global liverwort and hornwort flora. The checklist is derived from a working data set centralizing nomenclature, taxonomy and geography on a global scale. Prior to this effort a lack of centralization has been a major impediment for the study and analysis of species richness, conservation and systematic research at both regional and global scales. The success of this checklist, initiated in 2008, has been underpinned by its community approach involving taxonomic specialists working towards a consensus on taxonomy, nomenclature and distribution

    rs1004819 Is the Main Disease-Associated IL23R Variant in German Crohn's Disease Patients: Combined Analysis of IL23R, CARD15, and OCTN1/2 Variants

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    The IL23R gene has been identified as a susceptibility gene for inflammatory bowel disease (IBD) in the North American population. The aim of our study was to test this association in a large German IBD cohort and to elucidate potential interactions with other IBD genes as well as phenotypic consequences of IL23R variants. Genomic DNA from 2670 Caucasian individuals including 833 patients with Crohn's disease (CD), 456 patients with ulcerative colitis (UC), and 1381 healthy unrelated controls was analyzed for 10 IL23R SNPs. Genotyping included the NOD2 variants p.Arg702Trp, p.Gly908Arg, and p.Leu1007fsX1008 and polymorphisms in SLC22A4/OCTN1 (1672 C-->T) and SLC22A5/OCTN2 (-207 G-->C). All IL23R gene variants analyzed displayed highly significant associations with CD. The strongest association was found for the SNP rs1004819 [P = 1.92x10(-11); OR 1.56; 95 % CI (1.37-1.78)]. 93.2% of the rs1004819 TT homozygous carriers as compared to 78% of CC wildtype carriers had ileal involvement [P = 0.004; OR 4.24; CI (1.46-12.34)]. The coding SNP rs11209026 (p.Arg381Gln) was protective for CD [P = 8.04x10(-8); OR 0.43; CI (0.31-0.59)]. Similar, but weaker associations were found in UC. There was no evidence for epistasis between the IL23R gene and the CD susceptibility genes CARD15 and SLC22A4/5. IL23R is an IBD susceptibility gene, but has no epistatic interaction with CARD15 and SLC22A4/5. rs1004819 is the major IL23R variant associated with CD in the German population, while the p.Arg381Gln IL23R variant is a protective marker for CD and UC

    SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

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    Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant
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