Sökning: "Ekologisk botanik"

Visar resultat 21 - 25 av 66 avhandlingar innehållade orden Ekologisk botanik.

  1. 21. Importance of tannins for responses of aspen to anthropogenic nitrogen enrichment

    Författare :Franziska Bandau; Benedicte Albrectsen; Michael Gundale; Lisbeth Josson; Umeå universitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; aspen; foliar condensed tannins; genetic variability; anthropogenic nitrogen enrichment; plant growth; plant defense; litter decomposition; Populus tremula; asp; kondenserade tanniner; genetisk variabilitet; antropogent kväve; tillväxt; växtförsvar; förna nedbrytning; Populus tremula; Environmental Science; miljövetenskap; ekologisk botanik; Ecological Botany; Entomology; entomologi; Physiological Botany; fysiologisk botanik; Population Biology; populationsbiologi;

    Sammanfattning : Boreal forests are often strongly nitrogen (N) limited. However, human activities are leading to increased N inputs into these ecosystems, through atmospheric N deposition and forest fertilization. LÄS MER

  2. 22. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem : Bottom-up effects in an aquatic food web

    Författare :Norbert Häubner; Pauli Snoeijs; Jon Ågren; Rhena Schumann; Markku Viitasalo; Uppsala universitet; []
    Nyckelord :Baltic Sea; carotenoids; astaxanthin; tocopherols; Vitamin E; thiamine; Vitamin B1; pelagic food web; eutrophication; M74; phytoplankton; zooplankton; sprat; Sprattus sprattus balticus; herring; Clupea harengus; salmon; Salmo salar; cod; Gadus morhua; High Performance Liquid Chromatography HPLC ; electrochemical detection ECD ;

    Sammanfattning : The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish. LÄS MER

  3. 23. Plant-Animal Interactions and Evolution of Floral Display and Flowering Phenology in Arabidopsis lyrata

    Författare :Saskia Sandring; Jon Ågren; Johan Ehrlén; José Gómez; Uppsala universitet; []
    Nyckelord :Ecology; Arabidopsis lyrata; natural selection; floral display; phenology; flowering time; plant-animal interactions; pollination; herbivory; selection gradients; population differentiation; local adaptation; Ekologi;

    Sammanfattning : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits, and population differentiation in the insect-pollinated, outcrossing, perennial herb Arabidopsis lyrata. More specifically, I (1) determined whether selection on flowering phenology and floral display can be attributed to interactions with pollinators and herbivores, (2) examined whether population differentiation in flowering phenology and floral display is correlated with current selection on these traits, and (3) tested for local adaptation from contrasting environments in Europe. LÄS MER

  4. 24. Plant Population Dynamics and Conservation in Wooded Hay-Meadows – Effects of Intensified Management

    Författare :Lotta Wallin; Brita M. Svensson; Mikael Lönn; Johan Ehrlén; Uppsala universitet; []
    Nyckelord :Biology; coordinates; demographic model; dispersal; hay-meadow; Hypochoeris maculata; litter; management; Polygala amarella; stochastic modelling; Succisa pratensis; Biologi;

    Sammanfattning : The decrease in number and area of managed hay-meadows over the last century, in combination with the reduction of traditional management, threatens the biodiversity connected to these habitats. I experimentally examined how management intensity affected meadow characteristics and long-term population viability of three vascular plant species in wooded hay-meadows on the Swedish island of Gotland in the Baltic Sea. LÄS MER

  5. 25. Metapopulations dynamics and sex-specific resource allocation in Silene dioica

    Författare :Elisabet Peedu; Pär Ingvarsson; Barbara Giles; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Silene dioica; Skeppvik Archipelago; Metapopulation Dynamics; Population Genetic Structuring; Genetic Diversity; Gene Flow; Sex-Specific Resource Allocation; Cost of Reproduction; Life-History Theory; Sexual Dimorphism; Reproductive Effort; biology; biologi; evolutionär genetik; evolutionary genetics; ekologisk botanik; Ecological Botany;

    Sammanfattning : Rising archipelagos provide unique settings for the study of the temporal and spatial dynamics of their biota. This offers the possibility to study the ecology and genetics of early successional processes; both between islands that differ in age and within islands when already established organisms have to keep pace with the changing environment. LÄS MER