41 research outputs found

    An unusual growth form of Cladonia furcata: The trampling-resistant primary thallus colonizing a paved pathway

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    Lichens are well known to be susceptible to damage by trampling. Fruticose species, with their highly branched structure, are particularly sensitive and Bayfield et al. (1981) described substantial damage to Cladonia uncialis, C. arbuscula, C. rangiferina, and C. impexa on paths in lichen-rich heath communities in north-east Scotland. Less visible communities, biotic soil crusts in arid and semi-arid areas with their cover of crustose lichens, are also easily disturbed by walking, car driving, or grazing and recovery can take decades. We report here an interesting situation where a lichen (Cladonia furcata) is apparently being maintained and even spread in a habitat because trampling prevents it from completing its monocarpic life cycle

    Statement by Anonymous collected by Marilyn Bronzi on August 27, 2014

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    This study is about finding methods for reusing of packaging from Elekta's product "Leksell Gamma Knife ICON" with Circular Economy as the focus. There is no process for this today. The important thing is the analysis of the entire supply chain from Suppliers to customer and then back to Suppliers to get general ideas about what the problems are and then to draw conclusions for the opportunities that exists. The methods used are analyzes if it is cost-effective and environmentally efficient to transport back packaging to the Suppliers who handle these packaging. Costs for the return process have been calculated, which is Supplier work, packaging costs, packaging costs and transport costs. Transport emission in the form of carbon dioxide equivalents have been calculated in the return process. Carbon dioxide equivalents have been calculated for the manufacturing of new packaging and transport by road and ship. The calculated values in the return process are compared with how Elekta is doing today during the process of packing LGK as well as delivering to customers to identify if it is effective to implement a new return process. A solution proposal that fulfils the requirements from an environmental and economic perspective is reported. Environmentally, it is reduced by 459 CO2eq number of carbon dioxide equivalents with transport from the US, 457 CO2eq from China and 1185 CO2eq from Europe. Financially, the company saves 17 190 SEK with transport from the USA, 19327 SEK from China and 18 126 SEK from Europe.Denna studie handlar att om att hitta metoder för Ă„teranvĂ€ndning av emballagen frĂ„n Elektasprodukt ”Leksell Gamma Knife ICON” med CirkulĂ€r ekonomi som fokus. Det finns ingen process för detta i dagslĂ€get. Den viktiga Ă€r analysen av hela försörjningskedjan frĂ„n leverantör till kund och sedan tillbaka till leverantörer för att fĂ„ generella uppfattningar om vad problemen befinner sig och dĂ€r ifrĂ„n dra slutsatser för möjligheterna som finns. De metoder som anvĂ€nds Ă€r analyser om det Ă€r kostnads- och miljöeffektivt att transportera tillbaka emballage till de leverantörer som hanterar dessa emballage. Kostnader för returprocessen har berĂ€knats vilket Ă€r leverantörsarbete, emballagekostnader, arbetskostnader och transportkostnader. TransportutslĂ€pp i form av koldioxidekvivalenter har berĂ€knats i returprocessen. Koldioxidekvivalenter har berĂ€knats för tillverkning av nya emballage samt transport med lastbil och fartyg. De berĂ€knade vĂ€rden i returprocessen jĂ€mförs med hur Elekta gör idag under processen att packa LGK samt leverera till kund för att identifiera om det Ă€r effektivt att implementera en ny returprocess. Ett lösningsförslag dĂ€r kraven uppfylls ur ett miljömĂ€ssigt och ekonomisk perspektiv redovisas. MiljömĂ€ssigt minskas det med 459 CO2eq antal koldioxidekvivalenter med transport frĂ„n USA, 457 CO2eq frĂ„n Kina och 1185 CO2eq frĂ„n Europa. Ekonomiskt sparar företaget pĂ„ 17 190 SEK med transport frĂ„n USA, 19327 SEK frĂ„n Kina och 18 126 SEK frĂ„n Europa

    Diversity of Lecidea (Lecideaceae, Ascomycota) species revealed by molecular data and morphological characters

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    The diversity of lichens, especially crustose species, in continental Antarctica is still poorly known. To overcome difficulties with the morphology based species delimitations in these groups, we employed molecular data (nuclear ITS and mitochondrial SSU rDNA sequences) to test species boundaries within the genus Lecidea. Sampling was done along a north–south transect at five different areas in the Ross Sea region (Cape Hallett, Botany Bay to Mount Suess, Taylor Valley, Darwin Area and Mount Kyffin). A total of 153 specimens were collected from 13 localities. Phylogenetic analyses also include specimens from other regions in Antarctica and non-Antarctic areas. Maximum parsimony, maximum likelihood and Bayesian analyses agreed in placing the samples from continental Antarctica into four major groups. Based on this phylogenetic estimate, we restudied the micromorphology and secondary chemistry of these four clades to evaluate the use of these characters as phylogenetic discriminators. These clades are identified as the following species Lecidea cancriformis, L. andersonii as well as the new species L. polypycnidophora Ruprecht & TĂŒrk sp. nov. and another previously unnamed clade of uncertain status, referred to as Lecidea sp. (L. UCR1)

    Quantified vegetation change over 42 years at Cape Hallett, East Antarctica

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    This paper reports on the remapping of a carefully documented vegetation plot at Cape Hallett (72°19â€ČS 170°16â€ČE) to provide an assessment of the rates of vegetation change over decadal time scales. E.D. Rudolph, in 1962, mapped in detail the vegetation of a site approximately 28 m by 120 m at Cape Hallett, Victoria Land, Antarctica. This site was relocated and remapped in January 2004 and changes were assessed using GIS techniques. This appears to be the longest available time period for assessing vegetation change in Antarctica. The analysis indicated that considerable change had occurred in moss and algae distribution patterns and this seems to have been caused by increased water supply, particularly in wetter areas. There was also evidence of some change in lichen distribution. The extent of the change indicates that vegetation cover can be used for monitoring change in areas as extreme as the Ross Sea region. For this analysis to be successful it was important that the mapping techniques used were totally explicit and could easily be replicated. Fortunately, Rudolph had defined his cover classes and the site was also clearly marked. The application of GIS mapping techniques allows the mapping to be more explicitly defined and easily replicated

    Photosynthetic responses of three common mosses from continental Antarctica

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    Predicting the effects of climate change on Antarctic terrestrial vegetation requires a better knowledge of the ecophysiology of common moss species. In this paper we provide a comprehensive matrix for photosynthesis and major environmental parameters for three dominant Antarctic moss species (Bryum subrotundifolium, B. pseudotriquetrum and Ceratodon purpureus). Using locations in southern Victoria Land, (Granite Harbour, 77°S) and northern Victoria Land (Cape Hallett, 72°S) we determined the responses of net photosynthesis and dark respiration to thallus water content, thallus temperature, photosynthetic photon flux densities and CO2 concentration over several summer seasons. The studies also included microclimate recordings at all sites where the research was carried out in field laboratories. Plant temperature was influenced predominantly by the water regime at the site with dry mosses being warmer. Optimal temperatures for net photosynthesis were 13.7°C, 12.0°C and 6.6°C for B. subrotundifolium, B. pseudotriquetrum and C. purpureus, respectively and fall within the known range for Antarctic mosses. Maximal net photosynthesis at 10°C ranked as B. subrotundifolium > B. pseudotriquetrum > C. purpureus. Net photosynthesis was strongly depressed at subzero temperatures but was substantial at 0°C. Net photosynthesis of the mosses was not saturated by light at optimal water content and thallus temperature. Response of net photosynthesis to increase in water content was as expected for mosses although B. subrotundifolium showed a large depression (60%) at the highest hydrations. Net photosynthesis of both B. subrotundifolium and B. pseudotriquetrum showed a large response to increase in CO2 concentration and this rose with increase in temperature; saturation was not reached for B. pseudotriquetrum at 20°C. There was a high level of variability for species at the same sites in different years and between different locations. This was substantial enough to make prediction of the effects of climate change very difficult at the moment

    Summer activity patterns for a moss and lichen in the maritime Antarctic with respect to altitude

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    There is considerable scientific interest as to how terrestrial biodiversity in Antarctica might respond, or be expected to respond, to climate change. The two species of vascular plant confined to the Antarctic Peninsula have shown clear gains in density and range extension. However, little information exists for the dominant components of the flora, lichens and bryophytes. One approach has been to look at change in biodiversity using altitude as a proxy for temperature change and previous results for Livingston Island suggested that temperature was the controlling factor. We have extended this study at the same site by using chlorophyll fluorometers to monitor activity and microclimate of the lichen, Usnea aurantiaco-atra, and the moss, Hymenoloma crispulum. We confirmed the same lapse rate in temperature but show that changes in water relations with altitude is probably the main driver. There were differences in water source with U. aurantiaco-atra benefitting from water droplet harvesting and the species performed substantially better at the summit. In contrast, activity duration, chlorophyll fluorescence and photosynthetic modelling all show desiccation to have a large negative impact on the species at the lowest site. We conclude that water relations are the main drivers of biodiversity change along the altitudinal gradient with nutrients, not measured here, as another possible contributor

    At limits of life: multidisciplinary insights reveal environmental constraints on biotic diversity in continental Antarctica

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    Multitrophic communities that maintain the functionality of the extreme Antarctic terrestrial ecosystems, while the simplest of any natural community, are still challenging our knowledge about the limits to life on earth. In this study, we describe and interpret the linkage between the diversity of different trophic level communities to the geological morphology and soil geochemistry in the remote Transantarctic Mountains (Darwin Mountains, 80uS). We examined the distribution and diversity of biota (bacteria, cyanobacteria, lichens, algae, invertebrates) with respect to elevation, age of glacial drift sheets, and soil physicochemistry. Results showed an abiotic spatial gradient with respect to the diversity of the organisms across different trophic levels. More complex communities, in terms of trophic level diversity, were related to the weakly developed younger drifts (Hatherton and Britannia) with higher soil C/N ratio and lower total soluble salts content (thus lower conductivity). Our results indicate that an increase of ion concentration from younger to older drift regions drives a succession of complex to more simple communities, in terms of number of trophic levels and diversity within each group of organisms analysed. This study revealed that integrating diversity across multi-trophic levels of biotic communities with abiotic spatial heterogeneity and geological history is fundamental to understand environmental constraints influencing biological distribution in Antarctic soil ecosystems.Catarina Magalhães, Mark I. Stevens, S. Craig Cary, Becky A. Ball, Bryan C. Storey, Diana H. Wall, Roman TƱrk and Ulrike Ruprech
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