Sökning: "[Ekologi]"

Visar resultat 1 - 5 av 1557 avhandlingar innehållade ordet [Ekologi].

  1. 1. Boreal vegetation responses to forestry as reflected in field trial and survey data and the quality of cover estimates and presence/absence in vegetation inventory

    Författare :Johan Bergstedt; Per Milberg; Göran Ståhl; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boreal forest; cutting intensity; scarification; cover estimates; presence absence; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : Den här avhandlingen belyser hur avverkning och markberedning påverkar markfloran i den svenska barrskogen. Dessutom utvärderas två inventeringsmetoder som används inom växtekologin. LÄS MER

  3. 2. Predators in low arctic tundra and their impact on community structure and dynamics

    Författare :Maano Aunapuu; Tarja Oksanen; Ola Atlegrim; Oswald J. Schmitz; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; arthropods; coexistence; community dynamics; competition; food webs; hypothesis of exploitation ecosystems; intraguild predation; small mustelids; trophic cascades; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

    Sammanfattning : The abundance of predators and their impact on ecosystem dynamics is a vividly discussed topic in current ecology. In my studies, incorporating field observations, field experiments and theoretical modeling, I explored the importance of predators and predation in a low arctic tundra ecosystem in northern Norway. LÄS MER

  4. 3. Biodiversity in fragmented boreal forests : assessing the past, the present and the future

    Författare :Håkan Berglund; Bengt Gunnar Jonsson; Jari Kouki; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; bryophytes; CWD; edge effects; fragmentation; fungi; habitat destruction; historical records; indicator; lichens; regression; species-area relationship; value pyramids; woody debris; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The aims of this thesis are to (1) analyze the predictability (indicators) of plant and fungal species diversity in old-growth forests, and (2) assess the history and biodiversity of woodland key habitats (WKHs) and their potential to maintain species diversity in fragmented boreal forest landscapes. Predictability was explored in Granlandet nature reserve, an unexploited landscape composed of discrete old-growth Picea forest patches of varying size isolated by wetland, reflecting conditions of insular biota at stochastic equilibrium. LÄS MER

  5. 4. Macroalgae in the Baltic Sea : responses to low salinity and nutrient enrichment in Ceramium and Fucus

    Författare :Lena Bergström; Lars Ericson; Lena Kautsky; Erik Bonsdorff; Christine A Maggs; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; adaptation; asexual reproduction; Baltic Sea; Gulf of Bothnia; salinity; macroalgae; nutrients; sexual reproduction; stress; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The brackish Baltic Sea is a marginal environment for both marine and freshwater species. The rate of ecological differentiation is presumably high due to strong selection pressure from a gradient of decreasing salinity that has been present in its current state for only about 3 000 years. LÄS MER

  7. 5. Spatial heterogeneity and biotic interactions : scaling from experiments to natural systems

    Författare :Ulf Bergström; Göran Englund; Erik Bonsdorff; Sebastian Diehl; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

    Sammanfattning : Much of current ecological theory stems from experimental studies. These studies have often been conducted in closed systems, at spatial scales that are much smaller than the systems of interest. LÄS MER