Sökning: "ecology"

Visar resultat 11 - 15 av 1819 avhandlingar innehållade ordet ecology.

  1. 11. The Threat to the Baltic Salmon - a Combination of Persistent Pollutants, Parasite and Oxidative Stress

    Författare :Maria Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Salmo salar; Atlantic salmon; polychlorinated biphenyls; Animal ecology; akvatisk ekologi; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; lake Vänern; lake Vättern; Baltic Sea; Eubothrium crassum; aryl hydrocarbon receptor; AHR; consumption advice; stable isotopes; astaxanthin; EROD; M74; antioxidants; biomagnification; cestodes; parasites; DDT; Djurekologi; Environmental chemistry; Miljökemi; PCB;

    Sammanfattning : Atlantic salmon (Salmo salar) from the Baltic Sea suffer from a reproduction disease known as the M74-syndrome. Newly hatched fry develop nerve disorders and die between 3-5 days after the first symptoms are seen. This is a maternally transmitted disease that is casued by a thiamine (vitamin B1) deficiency. LÄS MER

  3. 12. Biodiversity in Agricultural Landscapes: Landscape and Scale-Dependent Effects of Organic Farming

    Författare :Maj Rundlöf; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Djurekologi; Natural science; Naturvetenskap; Ekologi; Animal ecology; plants; spatial scales; species richness; Ecology; landscape ecology; agri-environment schemes; farming practice; conservation; butterflies; bumble bees;

    Sammanfattning : Declines in the distribution and abundance of many farmland species during recent decades have been attributed to agricultural intensification. Agri-environment schemes are commonly used in Europe to reduce this loss of farmland biodiversity, but their effectiveness may depend on several external factors. LÄS MER

  4. 13. Internal oxygen transport to below-ground parts: importance for emergent macrophytes

    Författare :Viveka Vretare Strand; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; water depth; zonation; phenotypic plasticity; biomass allocation; pressurised ventilation; oxygen; Phragmites australis; emergent macrophytes; common reed; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Sammanfattning : This thesis examines factors regulating growth and distribution of emergent plants with focus on effects of oxygen supply to the roots. Greenhouse experiments revealed that P. australis acclimatizes to specific water depths with phenotypic plasticity. LÄS MER

  5. 14. Environmental-flow assessments for current and future run-off in a large river system regulated for hydropower production

    Författare :Åsa Widén; Roland Jansson; Birgitta Malm-Renöfält; Michael McClain; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental flows; eco-hydrology; hydropower; river ecosystem; environmental benefits; climate change; collaboration; resource management; Ekologisk reglering; vattenkraft; produktionsoptimering; hydrologi; hydraulik; akvatiskt ekosystem; miljönytta; klimatförändringar; samverkan; vattenresurs management;

    Sammanfattning : In 2019, Sweden implemented legislative changes to renegotiate hydropower permits to both consider environmental rehabilitation and to ensure national supply of hydropower. This means that efforts for environmental rehabilitation of the 2,000 hydropower plants in Sweden need to be considered. LÄS MER

  7. 15. Butterfly Diversity and Dispersal in Fragmented Grasslands

    Författare :Erik Öckinger; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Naturvetenskap; Djurekologi; Animal ecology; Ekologi; Ecology; Lepidoptera; Landscape ecology; Insects; Species richness; Fragmentation; Mobility; Natural science; Source-sink dynamics; Metapopulations;

    Sammanfattning : During the last decades, the distribution and abundance of many European species of birds, plants and insects in agricultural landscapes have declined due to agricultural intensification. To be able to mitigate these declines, it is essential to know the relative importance on local and regional ecological processes on population persistence and patterns of species richness. LÄS MER