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Showing result 1 - 5 of 8 swedish dissertations matching the above criteria.
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1. Evolutionary Processes and Hybridization within the Peat Mosses, Sphagnum
Abstract : The aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. READ MORE
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2. Subarctic ecosystem responses to climate, catchment and permafrost dynamics in the Holocene
Abstract : This thesis assesses aspects of the wetland development, permafrost dynamics and associated changes in carbon and nutrient cycling of the Stordalen Mire in northern Sweden. Various ecological and biogeochemical analyses of one peat and two lake sediment sequences were conducted, including analyses of organic matter and carbonate content, mosses, diatoms, testate amoebae, pigments, carbon and nitrogen and their stable isotopes, near infrared spectroscopy and biogenic silica. READ MORE
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3. The ecological significance of sexual reproduction in peat mosses (Sphagnum)
Abstract : Peat mosses (Sphagnum) are widely distributed and are a major component of mire vegetation and peat throughout the boreal and temperate regions. Most boreal Sphagnum species regularly produce sporophytes, but the ecological role of the spore has been questioned. READ MORE
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4. Functional Traits in Sphagnum
Abstract : Peat mosses (Sphagnum) are ecosystem engineers that largely govern carbon sequestration in northern hemisphere peatlands. I investigated functional traits in Sphagnum species and addressed the questions: (I) Are growth, photosynthesis and decomposition and the trade-offs between these traits related to habitat or phylogeny?, (II) Which are the determinants of decomposition and are there trade-offs between metabolites that affect decomposition?, (III) How do macro-climate and local environment determine growth in Sphagnum across the Holarctic?, (IV) How does N2 fixation vary among different species and habitats?, (V) How do species from different microtopographic niches avoid or tolerate desiccation, and are leaf and structural traits adaptations to growth high above the water table?Photosynthetic rate and decomposition in laboratory conditions (innate growth and decay resistance) were related to growth and decomposition in their natural habitats. READ MORE
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5. The fate of airborne lead pollution in boreal forest soils
Abstract : Lead has a more than three-millennia-long pollution history in Europe. Metal production, burning of coal and use of leaded petrol resulted in a significant pollution of the atmosphere. As a consequence of atmospheric fallout, the Swedish boreal forest is strongly contaminated by airborne lead pollution. READ MORE