690 research outputs found

    Modelling the Antarctic ozone hole

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    Researchers performed model calculations of the ozone depletions taking place in the Antarctic lower stratosphere. Making the assumption that odd nitrogen is frozen out on stratospheric haze particles, an analysis is given of how much homogeneous reactions can contribute to ozone loss during September-October. Comparisons with observations indicate the potential importance of reactions with HCl in the polar stratospheric cloud particles

    A broad typology of dry rainforests on the western slopes of New South Wales

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    Dry rainforests are those communities that have floristic and structural affinities to mesic rainforests and occur in parts of eastern and northern Australia where rainfall is comparatively low and often highly seasonal. The dry rainforests of the western slopes of New South Wales are poorly-understood compared to other dry rainforests in Australia, due to a lack of regional scale studies. This paper attempts to redress this by deriving a broad floristic and structural typology for this vegetation type. Phytogeographical analysis followed full floristic surveys conducted on 400 m2 plots located within dry rainforest across the western slopes of NSW. Cluster analysis and ordination of 208 plots identified six floristic groups. Unlike in some other regional studies of dry rainforest these groups were readily assigned to Webb structural types, based on leaf size classes, leaf retention classes and canopy height. Five community types were described using both floristic and structural data: 1) Ficus rubiginosa–Notelaea microcarpa notophyll vine thicket, 2) Ficus rubiginosa–Alectryon subcinereus–Notelaea microcarpa notophyll vine forest, 3) Elaeodendron australe–Notelaea microcarpa–Geijera parviflora notophyll vine thicket, 4) Notelaea microcarpa– Geijera parviflora–Ehretia membranifolia semi-evergreen vine thicket, and 5) Cadellia pentastylis low microphyll vine forest. Floristic groupings were consistent with those described by previous quantitative studies which examined smaller portions of this study area. There was also general agreement between the present analytical study and a previous intuitive classification of dry rainforest vegetation throughout the study area, but little concurrence with a continental scale floristic classification of rainforest

    Making Carex monophyletic (Cyperaceae, tribe Cariceae): a new broader circumscription

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113175/1/boj12298.pd

    Taxonomy and ecology of Sphagnum-associated Desmids from the New England Tablelands, New South Wales, Australia

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    Desmids associated with Sphagnum L. from terrestrial and aquatic habitats were investigated in the New England Tableland Bioregion. Descriptions and figures for 80 taxa are presented herein, nine of which are newly recorded for Australia, and a further seven are newly recorded for New South Wales. Two novel species of desmid, Micrasterias bicoronata A.Kenins and Cosmarium phymatodeum A.Kenins, are described. The floristic composition of desmids at Basket Swamp and Ebor Common, were compared to assess their conservation value based on an existing and modified scheme better suited to desmids from Australia. Basket Swamp received a relatively high score based on greater species richness and numerous endemics present. In contrast, Ebor Common scored lower due to less diversity and few regionally endemic species. This study also highlights that the desmid community found amongst Sphagnum in Australia is highly diverse (βSOR = 0.82) and can differ markedly among the four assessed sites due to spatial turnover (βRATIO = 0.15). While there are species in common with the much more extensively studied Sphagnum habitats in central and western Europe, Australia has its own distinctive desmid floral elements

    Towards a Comprehensive Survey of C3 and C4 Photosynthetic Pathways in Cyperaceae

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    Members of the family Cyperaceae were surveyed by original observation and from the literature to assess the distribution of C3 and C4 photosynthetic pathways in the family. All 107 genera were included in the current sample, with 91 genera assessed as consistently C3 and 11 genera as C4. The genera Abildgaardia, Cyperus, Eleocharis, Fimbristylis, and Rhynchospora are variable for this trait. Of the total number (1474) of specific (1406) and infraspecific (68) taxa sampled, 938 taxa (63%) are C3, 527 taxa (36%) are C4, and nine species of Eleocharis are debatably intermediate or variable in pathway. Some data suggesting further infrageneric variation in photosynthetic pathways are discussed. The ‘‘one cell distant criterion’’ accurately predicts C4 pathway in sedges, except in Eleocharis. Distribution and variability of photosynthetic pathways in Eleocharis are discussed. Photosynthetic pathway was found to be a useful taxonomic marker in Cyperaceae, despite variability in this trait at various taxonomic levels and the apparently multiple origin of C4 photosynthesis within the family. A checklist of 3395 records of C3 and C4 sedges is presented

    Morphological data indicate the subspecies of Leionema elatius (Rutaceae) are not conspecific

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    Morphological data show that the two subspecies currently assigned to Leionema elatius (Benth.) Paul G.Wilson (Rutaceae), namely L. elatius subsp. elatius and L. elatius subsp. beckleri (F.Muell.) Paul G.Wilson, are not conspecific. Leionema elatius subsp. beckleri is reinstated to the rank of species as L. beckleri (F.Muell.) I.Telford & J.J.Bruhl. The distributions of both species are mapped and their conservation status discussed. Images comparing the morphological attributes of the two species and a table comparing selected attributes of the species and the newly described L. praetermissum P.R.Alvarez & Duretto are presented. A key to species of Leionema found in New South Wales and south-eastern Queensland is provided

    Dodonaea crucifolia (Sapindaceae, Dodonaeoideae), a new species from north-eastern New South Wales, Australia

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    Dodonaea crucifolia I.Telford & J.J.Bruhl (Sapindaceae, Dodonaeoideae), endemic to north-eastern New South Wales, Australia, and previously confused with D. hirsuta (Maiden & Betche) Maiden & Betche, is described as new. Dodonaea hirsuta is recircumscribed with the D. crucifolia components removed and with male flowers described for the first time. The distribution, habitat and conservation status of both species are discussed and a table is provided comparing selected morphological attributes. Images of the new species and D. hirsuta are provided. The identification keys in Flora of Australia and NSW FloraOnline are modified to include the new species

    Elected Judges and Statutory Interpretation

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    This Article considers whether differences in methods of judicial selection should influence how judges approach statutory interpretation. Courts and scholars have not given this question much sustained attention, but most would probably embrace the “unified model,” according to which appointed judges (such as federal judges) and elected judges (such as many state judges) are supposed to approach statutory text in identical ways. There is much to be said for the unified model—and we offer the first systematic defense of it. But the Article also attempts to make the best case for the more controversial but also plausible contrary view: that elected judges and appointed judges should actually interpret statutes differently. We explain and defend that view and explore some of its implications and limits. We identify categories of cases in which the argument for interpretive divergence is at its strongest. We also show how the possibility of interpretive divergence might illuminate several specific doctrinal problems related to judicial federalism and judicial review of agency action

    Elected Judges and Statutory Interpretation

    Get PDF
    This Article considers whether differences in methods of judicial selection should influence how judges approach statutory interpretation. Courts and scholars have not given this question much sustained attention, but most would probably embrace the “unified model,” according to which appointed judges (such as federal judges) and elected judges (such as many state judges) are supposed to approach statutory text in identical ways. There is much to be said for the unified model—and we offer the first systematic defense of it. But the Article also attempts to make the best case for the more controversial but also plausible contrary view: that elected judges and appointed judges should actually interpret statutes differently. We explain and defend that view and explore some of its implications and limits. We identify categories of cases in which the argument for interpretive divergence is at its strongest. We also show how the possibility of interpretive divergence might illuminate several specific doctrinal problems related to judicial federalism and judicial review of agency action

    Plasticity in stomatal density and morphology in okra and tomatoes in response to soil and water salinity

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    Okra (Abelmoschus esculentus) and tomatoes (Lycopersicum esculentum) were grown in saline (3.0 dS m-1 NaCl) and non-saline soil and irrigated with saline (2.4 dS m-1 NaCl) or non-saline water to determine the response of stomatal density and morphology to salinity. Stomata density (stomata number per unit leaf area) for tomato grown on saline soil was reduced by 33% (12 mm-2) compared with those on non-saline soils (18 mm-2); this reduction was more severe on the adaxial leaf surface where stomatal density was low. Similar reductions in stomatal density were observed in tomato irrigated with saline water. Stomata size in tomato was significantly reduced by about 20% with both types of salinity, thus the proportion of leaf surface area occupied by the stomata in salt-stressed plants, i.e., stomata area index (SAI), averaged 4.4% in salt-stressed plants compared with 5.5% in plants grown in non-saline conditions. Okra, on the other hand, maintained a similar stomatal density (average 22 mm-2) on both saline and non-saline soils, but saline irrigation marginally increased the density. In okra, the abaxial leaf surface accounted for about 68% of the total stomata under both saline and non-saline conditions. Individual stoma size in okra was increased by up to 15% on both leaf surfaces due to salinity, hence, the SAI increased from an average of 9.0% under non-saline conditions to 11.7% under saline stress. Notwithstanding the increase in SAI for okra, salinity reduced stomatal conductance by more than 50% in both crops. The stomatal conductance was generally much larger in okra than in tomato, and was as large in okra exposed to salinity as for tomato in the absence of salinity
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