Search for dissertations about: "microcosm"

Showing result 1 - 5 of 43 swedish dissertations containing the word microcosm.

  2. 1. Denitrification as an adaptive trait in soil and groundwater bacteria

    Author : Christer Bergwall; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; microcosm; forest soil; aquifer; groundwater; reductase; nitrous oxide; nitric oxide; nitrite; nitrate; selection; adaptation; bacteria; nitrification; Denitrification; dissimilatory nitrate reduction to ammonium; fertiliser; 15NO3-; 15NH4 ; Ecology; Ekologi;

    Abstract : The focus of the thesis is on selection and adaptation processes in bacteria with emphasis on denitrifying bacteria in groundwater. Other nitrogen transformation processes such as dissimilatory nitrate reduction to ammonium (nitrate ammonification) and nitrification of forest soil bacteria are briefly discussed. READ MORE

  4. 2. Role of ecological processes in determining effects of contaminants in aquatic ecosystems

    Author : Anna-Lea Golz; Clare Bradshaw; Karen Kidd; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ecosystem approach; ionizing radiation; HBCDD; microcosm; species interactions; indirect effects; marin ekotoxikologi; Marine Ecotoxicology;

    Abstract : Aquatic ecosystems cover approximately 70% of the Earth’s surface and support a wide range of ecosystem services. Despite their importance, aquatic ecosystems are increasingly exposed to anthropogenic stressors, such as contaminants and climate change impacts. READ MORE

  5. 3. Assessing environmental and contaminant stressors in a benthic amphipod

    Author : Therese Jacobson; Brita Sundelin; Tamara Galloway; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Multiple stressors; Reproduction; Temperature; Food; Parasites; Fenarimol; PFOS; TBT; Endocrine disruption; Ecdysteroids; Microsporidia; Microcosm; Crustacea; Amhipoda; Monoporeia affinis; Biology; Biologi; Applied Environmental Science; tillämpad miljövetenskap;

    Abstract : Organisms in the aquatic environment encounter numerous stressors throughout their lifespan. Some of them are biotic such as food availability, predators and parasites. Others are abiotic and include shifting salinity and temperature change among others. READ MORE

  6. 4. Compositional clues to sources and sinks of terrestrial organic matter transported to the Eurasian Arctic shelf

    Author : Emma Karlsson; Örjan Gustafsson; Volker Brüchert; Thorsten Dittmar; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; organic carbon; degradation; microcosm; incubation; terrestrial biomarkers; acyl lipids; lignin phenols; radiocarbon; Eurasian Arctic shelf; East Siberian Sea; Laptev Sea; Lena River; colloidal matter; particulate matter; sedimentary matter; Applied Environmental Science; tillämpad miljövetenskap;

    Abstract : The amount of organic carbon (OC) present in Siberian Arctic permafrost soils is estimated at twice the amount of carbon currently in the atmosphere. The shelf seas of the Arctic Ocean receive large amounts of this terrestrial OC from Eurasian Arctic rivers and from coastal erosion. READ MORE

  7. 5. Ecotoxicological assessment by microcosm tests on plankton communities

    Author : Pardis Pirzadeh; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; aquatic ecology; limnology; Ecology; Ekologi; Hydrobiology; marine biology; musk substances; brominated flame retardants; structural effects; akvatisk ekologi; Environmental chemistry; Miljökemi; mesocosm;

    Abstract : The aim of this thesis is to present a short-term plankton community toxicity test in laboratory microcosms, with which the effect of the test substance on species abundance and composition of the community is evaluated. This laboratory microcosm is an intermediate between single-species tests and outdoor mesocosm tests. READ MORE